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COASTAL Z"NIE *~INFORMATIOIN CENTER o MARINE IfV% A cTECHNOLOGY ~ SOCIETY TRANSACTIONS OF O b- a ,T., - THE 2 ND ANNUAL lt/t MTS CONFERENCE & EXHIBIT COASTA ZONE JNORMATION CENTER .P, 3 O JUNE 27-29, 1966 _ S// MARINE _ TECHNOLOGY I> SOCIETY A Copyright O Marine Technology Society 1966 This piit51fcation may be obtained from Marine Technology Society, The Executive Building, 1030 15th Street N. W., Washington, D. C. 20005. Price $6. 00 each volume. Reprints of individual papers may be obtained from Kirby Lithographic Company5,4 tr SW, ashingtonD. C. Prices on request. companx Eddy"Pt r5 zl, D S ab �yr d -31 FOREWORD The Second Annual Conference and Exhibit of the Marine Technology Society has been developed to help the various industrial and government interests better to understand the problems involved with expanding ocean programs, and to discuss the most practical means of achieving goals of these different activities. The following organizations were associated with the Marine Technology Society in this development: Participants: American Mining Congress American Petroleum Institute Observers: American Bar Association: Section on International and Comparative Law, Section on Mineral and Natural Resources Law Cooperating Organizations: American Fisheries Society American Geophysical Union Institute of Navigation National Canners Association National Fisheries Institute Tuna Research Foundationi This volume contains the text of papers presented at the conference. They are published here in order to forward the policy of the Marine Technology Society to disseminate knowledge of the marine sciences. In organizing and developing these papers for presentation and dis- cussion, the assisting organizations and, even more importantly the individual authors, have made valuable contribution to the knowledge and understanding of the marine sciences. On behalf of the membership of the Marine Technology Society and of all participants at the conference and exhibit, grateful appreciation for this is affirmed. Richard C. Steere Chairman, Transactions Committee PREFACE During the year past the national interest in the oceans has grown at an accelerating rate with particularly strong em- phasis on resources important to our economy. It is not at all clear just what turn this increased interest will take in terms of commercial and industrial enterprise. One thing is clear, however, which this Conference Program reveals: we need much better information about the location, distribution and abun- dance of the resources of the oceans and about the economic factors and the technology of their removal as well as a clari- fication of the law regarding right of removal and ownership of the materials recovered. We hope this Conference will not only expose these issues but will provide a forum for their discus- sion by representatives of our federal and state governments, of industry and of the research and academic institutions con- cerned with the use of ocean resources for the national good. General Chairman "Exploiting The Ocean" CONFERENCE AND EXHIBIT COMMITTEE MTS Second Annual Conference & Exhibit The Executive Building 1030 15th Street, N. W. Washington, D.C. 20005 GENERAL CHAIRMAN Dr. James H. Wakelin, Jr., President VICE CHAIRMAN Scientific Engineering Institute Richard C. Vetter and formerly Assistant Secretary Executive Secretary, Committee of the Navy (Research and on Oceanography National Academy Development) of Sciences National Research Council HONORARY CHAIRMEN Honorable Arthur H. Dean, Esq. Dr. C. L. Bretschneider Chairman, U.S. Delegation 1958 & Vice President, National 1960, U.N. Conferences on the Engineering Science Company . Law of the Sea PROGRAM COMMITTEE R. G. Follis Chairman Chairman of Board Howard -H. Ekles Standard Oil Company of California Assistant to the Science Adviser Department of the Interior Dr. Melville Bell Grosvenor President and Editor Legal Aspects National Geographic Society Harry A. Inman, Esq. Dr. Augustus B. Kinzel Cdr. Larry G. Parks, USN, and The Salk Institute and President LCdr. Bruce Harlow, USN National Academy of Engineering Office of the Judge Advocate General of the Navy Admiral Arthur W. Radford U.S.N. (Ret.) Petroleum Aspects Formerly Chairman, Joint Chiefs Dr. Noyes D. Smith, Jr. of Staff Vice President, Shell Development Company Dr. Frederick Seitz, President National Academy of Sciences Mineral Aspects Robert W. Van Evera and Otis H. Smith, President Francis Bourne Upham III Fish Products Company American Mining Congress Clyde E. Weed, Chairman Fisheries Aspects Executive Committee, The Charles E. Jackson Anaconda Company and President Executive Vice President American Mining Congress International Shrimp Council PARTICIPANTS Social and Economic Aspects American Mining Congress James W. Oswald American Petroleum Institute Underseas Division Westinghouse Electric Corporation OBSERVERS Section on International and PUBLIC RELATIONS Comparative Law, and Section on Charles W. Covey Mineral and Natural Resources Law UnderSea Technology of the American Bar Association PRESS RELATIONS COOPERATING ORGANIZATIONS LCdr. C. W. Larson, USN American Fisheries Society Navy Deep Submergence Systems American Geophysical Union Program Institute of Navigation National Canners Association INTERNATIONAL RELATIONS National Fisheries Institute Ferdinand P. Diemer, Consultant Tuna Research Foundation Environmental Data Systems EXECUTIVE CHAIRMAN PROCEEDINGS RAdm. E. C. Stephan, USN (Ret.) Capt. R. C. Steere, USN (Ret.) Vice President, Ocean Systems, Inc. John I. Thompson & Company and President Marine Technology Society iii ARRANGEMENTS & SOCIAL AFFAIRS W. B. B. Lyons Kenneth H. Drummond Atlantic Research Corporation Texas Instruments Incorporated John C. Gelhard REGISTRATION General Electric Company Sydney 0. Marcus, Jr. National Oceanographic Data Center H. W. Porterfield John I. Thompson & Company FINANCE Gilbert L. Maton CONFERENCE MANAGER Executive Vice President Ted Evans John I. Thompson & Company The Conference Management Organization, Inc. TREASURER Julian Josephson EXHIBITION MANAGER Naval Oceanographic Office Frank Masters Trade Associates, Inc. V.I.P. _-dm. E. C. Stephan, USN (Ret.) EXECUTIVE SECRETARY Vice President, Ocean Systems, Inc. RAdm. M. H. Simons, Jr., USN (Ret.) Marine Technology Society Charles W. Skillas Sanders Associates, Inc. TABLE OF CONTENT.S Foreword.......................1 Preface by the General Chairman ................ Conference and Exhibit Committee ...............1i Table of Contents.................... V Authors Index .....................viii LEGAL ASPECTS OF OCEAN EXPLOITATION-STATUS AND OUTLOOK William T. Burke ..1................ GEOLOGICAL METHODS FOR LOCATING MINERAL DEPOSITS ON THE OCEAN FLOOR K. 0. Emery ....................24 SELECTING AREAS FAVORABLE FOR SUBSEA PROSPECTING V. E. McKelvey and Livingston Chase............44 REVIEW OF MINERAL VALUES ON AND UNDER THE OCEAN FLOOR John L. Mero ....................61 REVIEW OF AVAILABLE HARDWARE NEEDED FOR UNDERSEA MINING C. G. Welling and M. J. Cruickshank ............79 PETROLEUM RESOURCES OF THE CONTINENTAL MARGINS OF THE UNITED STATES T. W. Nelson and C. A. Burk ...............116 EXPLORATION ENGINEERING AND INSTRUMENTATION PROBLEMS IN THE MARINE ENVIROMENT B. W. Davis.....................134 POSITION DETERMINATION UNDER THE SEA Kenneth V. Mackenzie .................147 DYNAMIC ANCHORING OF FLOATING VESSELS K. W. Foster ....................158 ROLE OF GOVERNMENT IN OCEAN FISHERIES EXPLOITATION-AN INDUSTRY VIEW Lowell Wakefield...................173 FISHERY SCIENCE AND THE PREDICTION OF COMMERCIAL FISH LANDINGS Gordon C. Broadhead..................177 MINING INDUSTRY'S ROLE IN DEVELOPMENT OF UNDERSEA MINING IGordon 0. Pebrson ..................182 THE GOVERNMENT'S PROGRAM FOR ENCOURAGING THE DEVELOP- MENT OF A MARINE MINING INDUSTRY Walter R. Hibbard, Jr. ................197 LEGAL CLIMATE FOR UNDERSEAS MINING Elmer F. Bennett...................204 SOME ASPECTS OF WAVE FORECASTING ON THE PACIFIC COAST Richard Kent and R. R. Strange ..............211 V DRILLING IN THE SEA FROM FLOATING PLATFORMS N. E. Montgomery ................................... 230 MARINE COMPLETION SYSTEMS Leonard E. Williams ................................. 251 TELEMANIPULATOR SYSTEMS FOR DEEP-SEA OPERATIONS Dr. John W. Clark .................................. 279 UNDERWATER PIPELINES M. J. Lamb ....................................... 293 OCEAN ENVIROMENT AND FISH DISTRIBUTION AND ABUNDANCE Oscar E. Sette ..................................... 309 METHODS OF SEARCH AND CAPTURE IN OCEAN FISHERIES Dayton L. Alverson and Edward A. Schaefers ................. 319 THE KIND OF OCEANOGRAPHIC INFORMATION OF DIRECT USE TO THE FISHERMEN August Felando ..................................... 336 ENGINEERING NEEDS FOR FISHERY DEVELOPMENT Harvey R. Bullis, Jr ................................. 342 DEVELOPMENT OF LAW FOR OCEAN ACTIVITIES William L. Griffin ................................... 348 TOWARD A POLITICAL THEORY OF THE OCEAN James W. Oswald ................................... 358 THE LAWS GOVERNING EXPLOITATION OF THE MINERALS BENEATH THE SEA Northcutt Ely ...................................... 373 THE LEGAL STATUS OF MINERALS LOCATED ON OR BENEATH THE OCEAN FLOOR BEYOND THE CONTINENTAL SHELF William C. Tubman .................................. 379 OUR NEWEST FRONTIER: THE SEABOTTOM. SOME LEGAL ASPECTS OF THE CONTINENTAL SHELF STATUS Alban Weber ...................................... 405 THE ENGINEERING OF SEA SYSTEMS John P. Craven and Willard F. Searle ...................... 412 POWER UNDER THE SEA J. C. Louzader and G. F. Turner ......................... 424 THE DEVELOPMENT OF AN INTEGRATED LIFE SUPPORT SYSTEM FOR THE DEEP DIVING RESEARCH SUBMERSIBLE DS 4000 A. Pete Ianuzzi ..................................... 436 AUTOMATIC VERTICAL PROFILING OCEANOGRAPHIC DATA SYSTEMS A. Edward Wheeler .................................. 464 UNDERWATER ELECTRICAL CABLES & CONNECTORS ENGINEERED AS A SINGLE REQUIREMENT Don K. Walsh ...................................... 469 DYNAMIC TESTING OF CABLES J. C. Poffenberger, E. A. Capadona, R. B. Siter ............... 485 MAN IN THE SEA AND FISHERIES OF THE FUTURE Frank J. Hester .................................... 524 vi MARINE PROTEIN CONCENTRATE Donald G. Snyder...................530 THE FUTURE OF THE GREAT LAKES FISHERIES Claude Ver Duin ...................535 RECENT ADVANCES IN U. S. FISHING VESSEL DESIGN - FORECASTS AND TRENDS Robert F. Allen ...................542 MARINE TECHNOLOGY SOCIETY...............565 MTS CORPORATE MEMBERS ................566 CONFERENCE EXHIBITORS .................568 vii AU TR HORS3 IND EX (Mail addresses are listed for one author of each paper. Other authors collaborating, are listed by name only). Robert F. ALLEN.....................542 Marine Construction & Design Co. 2300 West Commodore Way Seattle, Washington 98199 Dayton L. ALVERSON ...................319 Bureau of Commercial Fisheries Department of the Interior Washington, D.C. 20240 Elmer F. BENNETT....................204 General Counsel, Public Land Law Review Commission 1730 K Street, N.W. Washington, D.C. 20006 Gordon C. BROADHEAD~...................177 Van Camp Seafood Company Division Ralston Purina Company 840 Van Camp Street Port of Long Beach 2, California Harvey R. BULLIS, Jr ...................342 Bureau of Commercial Fisheries Department of the interior Washington, D.C. 20240 C. A. BURK....................... 116 William T. BURKE ..1................. College of Law Ohio State University Columbus, Ohio 43210 H. A. CAPADONA. ....................48 5' Livings ton CHASE ....................44 Dr. John W. CLARK ...................279 Consultant 5252 Pendleton Street San Diego, Calif. 92109 John P. CRAVEN ....................412 Chief Scientist Special Projects Office Navy Department Washington, D.C. 20360 M. J. CRUICKSHANK ...................79 Northcutt ELY ......;................373 Ely and Duncan, Counsellors at Law Tower Building Washington, D.C. 20005 B. W. DAVIS ......................134 Texas Instruments Incorporated P.O. Box 5621 Dallas, Texas 75222 K. 0. EMERY......................24 Woods Hole Oceanographic Institution Woods Hole, Massachusetts August FELANDO ....................336 American Tuna Boat Association No. I Tuna Lane San Diego, California X. W. FOSTER .....................158 The Baylor Co., Inc. 5310 Glenmont Houston, Texas 77036 viii William L. GRIFFIN ...................348 Temple University School of Law 1715 North Broad Street Philadelphia Pa. 19122 Frank J. HESTER ....................524 U.S. Bureau of Commercial Fisheries Tana Resources Laboratory, P.O. Box 271 La Jolla., California 92037 Dr. Walter BR. HIBBARD, Jr .................197 Director, Bureau of Mines Department of the Interior Washington, D.C. 20240 A. Pete lanuzzi .....................436 Westinghouse Underseas Division P.O. Box 1797 Baltimore, Maryland 21203 Richard KENT .....................405 Oceanographic Services, Inc. 1911 De La Vina Street Santa Barbara, California 93101 MI. J. LAMB ......................293 Shell Pipe Line Corporation P.O. Box 2648 Houston, Texas 77001 J. C.LAUZADER ....................424 Senior Research Engineer Lockheed Missile & Space Company Sunnyvale, California Kenneth V. MACKENZIE..................147 Chief Scientist, Deep Submergence Program U.S. Navy Electronics Laboratory San Diego, California 92152 V. E. McKELVEY ....................44 U.S. Geological Survey Washington, D.C. 20240 John L. MERO .....................61 Ocean Resources, Inc. P.O. Box 2244 La Jolla, California N.H. MONTGOMERY...................230 Shell Oil Company 1008 West Sixth Street Los Angeles, California 90054 T. W. NELSON .....................116 Senior Vice President Socony Mobil Oil Company, Inc. 150 East 42 Street New York, New York 10017 James W. OSWALD....................358 Underseas Division, MS 1401 Westinghouse Electric Corp. P.O. Box 1797 Baltimore, Maryland 21203 Gordon C. PEHRSON ...................182 International Minerals and Chemical Corp. old Orchard Road Skokie, fIllinois ix J. C. POFFENBERGER .................................. 485 Preformed Line Products Company Research and Engineering Department 5300 St. Clair Avenue Cleveland, Ohio 44103 Edward A. SCHAEFERS .................................. 319 Willard F. SEARLE ..................................... 412 Oscar E. SETTE ....................................... 309 Bureau of Commercial Fisheries Biological Laboratory 450-B Jordan Hall Stanford, California 94305 R. B. SITER .......................................... 485 R. R. STRANGE .......................................211 Donald G. SYNDER ..................................... 530 Bureau of Commercial Fisheries Technical Laboratory College Park, Maryland William C. TUBMAN .................................... 379 Kennecott Copper Association 161 East 42nd Street New York 17, New York G. F. TURNER ........................................ 424 Claude VER DUIN ...................................... 535 Executive Vice President Chamber of Commerce One Washington Street Grand Haven, Michigan 49417 Lowell WAKEFIELD .................................... 173 Wakefield Fisheries Port Wakefield, Alaska 99615 Don K. WALSH ........................................ 469 Vice President MARSH & MARINE/Vector Cable Company 5616 Lawndale Avenue Houston, Texas 77023 Alban WEBER ........................................ 405 Captain USNR Northwestern University Evanston, Illinois C. G. WELLING .......................................79 Lockheed Missiles & Space Company Dept. 56-01, Bldg. 106, PL 1 P.O. Box 504 Sunnyvale, California A. Edward WHEELER ...................................464 Beckman Instruments, Inc. 2500 Harbor Boulevard Fullerton, California 92634 Leonard E. WILLIAMS ................................... 251 Cameron Iron Works, Inc. P.O. Box 1212 Houston, Texas 77001 x LEGAL ASPECTS OF OCEAN EXPLOITATION -- STATUS AND OUTLOOK* William T. Burke College of Law, Ohio State University Abstract The present status of the international law of the sea is found in previous decisions about the allocation of authority over, and use of, ocean areas. The principal method of exer- cising control over the ocean is that of extending state authority to particular, usually specifically defined, areas or zones of the ocean. Describing the law of the sea, there- fore, involves the examination of decisions pertaining to internal waters, territorial sea, continental shelf, contig- uous zones, and the high seas, all of which refer to zones within which authority is allocated among states in different ways. The principal provisions of the Geneva Conventions on the law of the sea, concluded in 1958, contain most of the important principles of law relating to ocean exploitation. The outlook for the future of ocean exploitation within the framework of the international legal system is projected in terms of the impact of law upon certain important ocean activ- ities, either actual or anticipated. The possible need for clarification of the existing structure of law and for addi- tions to such structure is examined in the context of recent and prospective developments in hard mineral mining, fishery exploitation, and claims to the ocean floor for purposes other than mining. The task undertaken here is that of examining the present status of, and the future outlook for, legal arrangements that may affect some types of exploitation and use of the ocean and the resources therein.l The law with which we are specifically concerned is the international law of the sea, i.e., the law involved in relations primarily between nation-states, although other groups, including private associations and individuals, are also on occasion subject to this law as well. This focus on international law is not by any means intended to imply that national law and policy are not important. Quite obviously we need wise planning for, and effective implementation of a coherent national policy concerning ocean exploitation. How- ever, the point to be emphasized is that this national policy must be created, and its implementation occur, within an inter- national system which requires that any interest in the world ocean, advanced by the United States (or by any other state) as meriting international legal protection, must be reciprocally recognized when that same interest and demand for protection are advanced by other states. In short, there can be no avoid- ance of the task of clarifying the common interests of all states of the world in the ocean, even when the immediate objec- tive is that of ascertaining the interests of a single state, such as the United States. It is, therefore, entirely appropriate here to center discussion upon the international law of the sea, for it is this law which seeks to secure the common interests of all states in their use of the sea. The overriding objective of the decision process we call the international law of the sea is, in most general state- ment, that of promoting, and permitting, the fullest, most pro- ductive, and peaceful use of the ocean by all participants for achieving all their individual goals in the greatest measure possible. With this very general statement of goal as a guide it may be possible later to offer some comment on the outlook for the law of the sea as regards ocean exploitation. It is necessary, first, to offer brief summary of the past deci- sions that, as a whole, comprise the "present status" of the law of the sea. This involves, to be explicit, merely a general de- scription of what has happened; nothing in this descriptive state- ment is intended to suggest what the future may be like. When predictions are considered, as they are in a later section, they are labelled as such. The principal justification for describing the law of the sea arises, of course, because that law impinges, or may do so, upon ocean uses of various kinds. We are all aware that, traditionally, fishing and transportation were the most important ways man em- ployed the sea for the general advantage. And today these uses are still important but others must also now be accommodated within the legal framework or, at least, contemplated in such context. These later, and potential, uses include oil exploita- tion, hard mineral mining, the various practices of scientific inquiry and investigation, military uses other than navigation or traditional exercises, and territorial claims to the ocean floor.4 Although discussion of texisting law" could proceed in terms of these actual or likely methods of.ocean exploitation, clar- ity is probably better served by considering the ways states have actually made claims to authority over the oceans and have recognized these claims. The principal method of asserting claims to control or to regulate activities in the ocean is that of extending or seek- ing to extend state authority to particular, usually specifical- ly defined, areas or zones of the ocean. Description can, there- fore, economically proceed by examining the law relating to in- ternal waters, territorial sea, continental shelf, contiguous zones, and the high seas, all of which refer to zones within which authority is allocated in different ways. This enter- prise obviously requires also that reference be made to the delimitation of the boundaries of these various areas.5 With- in this framework the main objective is to provide background for discussion of the Impact of law upon certain of the activ- ities mentioned above. In describing the present situation frequent reference is made hereafter to the four Geneva Conventions on the Law of the Sea adopted as a result of a conference of 86 states held in 1958.6 These treaties were the culmination of nearly a decade of con- sideration by some of the states and were affected most Impor- tantly by the work of the International Law Commission, a sub- sidiary organ of the United Nations General Assembly. The con- ventions deal with (1) the territorial sea and contiguous zone, (2) the continental shelf, (3) the high seas, and (4) conserva- tion of fishery resources. The first three of these treaties 2 are presently in effect as between the twenty-two or nmore states which have signified their acceptance by ratification. The United States is a party to these three. The fourth, on fishery conservation, is not at this writing in effect but probably will be shortly and, again, the United States will be a party since it has been ratified already. States not a party to these Con- ventions are not bound by them, but to avoid misunderstanding it must be noted that at least two of these treaties, those on the territorial sea and the high seas, are generally regarded as expressing customary international law. The principles re- corded therein are, hence, binding on states as part of this body of law. The third convention, dealing with the continental shelf, also probably reflects, in some important respects, cus- tomary law, but there may be disagreement about whether some of the detailed provisions of the convention are, in fact, already a part of customary law. The treaty on conservation is a depar- ture from previously accepted principles and it is unlikely that states generally regard these provisions as binding on them in the absence of ratification of the treaty or, at least, explicit pronouncement of acceptance. INTERNAL WATERS Previous decisions fully establish that each state has full authority and control over activities within the areas of in- ternal waters, such as ports and certain bays and gulfs. The entry of ships to such waters is, thus, in practically all in- stances subject to the consent of the coastal state. There are a very few situations, more or less unique, in which access to these waters may be claimed as a matter of right./ All resources in this area are within the complete disposition of the coastal state. TERRITORIAL SEA The scope of state control over the marginal waters accepted as within the territorial sea is similarly well established, though here there is one important issue that remains controverted by some. Generally speaking the coastal state has complete authority over the resources, fishery and all others including those of the seabed and subsoil, of the territorial sea. Coastal authority over the access of foreign vessels and objects to the territorial sea is also wide, but not unlimited. Foreign vessels have a right of innocent passage, which is understood to mean that vessels are normally entitled to pass through the territorial sea so long as the passage is not "prejudicial to the peace, good order or security of the coastal state. The wide range of coastal interests which might be subsumed under such terms of high-level generality as "peace, good order and security" as- sures the coastal state of ample, but not unlimited, authority to protect legitimate interests. In addition the "coastal state may, without discrimination amongst foreign ships, suspend temporarily in specified areas of its territorial sea the inno- cent passage of foreign ships if such suspension is essential for the protection of its security." Suspension cannot be made effective until after publication. The major issue still controverted concerns whether warships are entitled to invoke the right of innocent passage. Without entering into long explanation it is believed that warships do have such a right in virtually the same sense as private or merchant vessels. 3 THE LIMIT OF INTERNAL WATERS Traditionally the areas denominated as internal waters were limited, but recent decisions have opened the way to inclusion of rather large expanses of the ocean. It is now generally regarded as permissible completely to include certain indenta- tions into the coast if the width of the opening does not ex- ceed 24 miles in length, and if the opening is wider then the coastal state may draw a baseline at the first place the in- dentation narrows to 24 miles. The effect of placing the base- line further from the shore is to enlarge the area of internal waters, to extend the limit of the territorial sea and contiguous zones further out from the coast, and to affect the limit of the continental shelf in some situations. In certain conditions of water-land conformation, the coastal state may employ a straight baseline system, using isolated bits of rock and islands offshore as points on the line. The general situation contemplated is described in Article 4(1) of the Convention on the Territorial Sea and Contiguous Zone: 1"n localities where the coastline is deeply indented and cut into, or if there is a fringe of islands along the coast in its immediate vicinity, the method of straight baselines joining appropriate points may be employed in drawing the baseline from which the territorial sea is measured." The first application of this system, which preceded its in- clusion in the Convention, occurred in Norway and, when chal- lenged, was supported by the International Court as conforming with international law." Subsequently the Convention included the above provision and it promises to furnish the basis for sometimes marked extensions of internal waters. As is probably evident the use of this system can have considerable impact on foreign fishing activities in near coastal areas. THE LIMIT OF THE TERRITORIAL SEA One of the two critical issues left unresolved at Geneva in 1958, and again at a later conference in 1960 convened to deal with it, was that of the permissible breadth for the territorial sea. There are two main reasons this question was widely re- garded as important: both access to fisheries in coastal waters and access by military vessels to important straits are, or might be, affected by the width claimed or accepted for the territorial sea. It is still necessary to be tentative in discussing the existence of a general consensus among states on this problem. The United States position, the one we claim for ourselves and urge on others, is that three miles is the only limit universally agreed as permitted by international law.9 At the same time there ap- pears to be a pattern emerging which may, perhaps sooner than later, indicate general, if tacit, agreement that a 6-mile ter- ritorial sea is permissible. There are, however, a number of states which claim a 12-mile territorial sea and a very few claim an even wider limit. In nearly universal opinion the lat- ter claims are contrary to international law. 4 CONTIGUOUS ZONES FOR SPECIAL PURPOSES There is general recognition today, as there has been for many decades, that realistic protection of coastal interests requires the state to extend certain of its regulations, applicable to foreign vessels, beyond the limit of its territory as represented by the boundary of the territorial sea. States have done so for a considerable variety of purposes and they continue to do so today. The most important of the purposes presently being sought by establishing zones of limited authority beyond the territorial sea is that of acquiring exclusive coastal access to fishery re- sources. This form of contiguous zone is closely associated with the question of determining a limit for the territorial sea and at Geneva in 1958 the most prominent proposals for explicit agreement on the latter issue were combined with provision for special fisheries limits beyond the territorial sea. The United States-Canadian proposal at Geneva in 1960, which failed of adoption by only one vote, would have established a 6-mile ter- ritorial sea plus a further 6-mile fishing zone which, with some qualifications, would have conferred the same rights over the fish resources there as the coastal state possesses in the ter- ritorial sea. Although there was general willingness, if not quite the two- thirds approval required for adoption, to accept a contiguous zone for fisheries, this proposition was tied to the proposal for a 6-mile territorial sea and died when the latter was not accepted. Hence, the general provision on the contiguous zone adopted at Geneva, and incorporated in the Convention on the Territorial Sea as Article 24, does not mention fisheries as one of the purposes for which a contiguous zone is permissible. Nonetheless, the recent developments, especially in western Europe, have in substantial effect implemented the U.S.-Canadian proposal and there is reason to believe that special exclusive fishing zones are, or will be, permissible under international law. The Geneva Convention on fishery conservation is not, in so many words, concerned with establishing contiguous zones for conservation purposes but it is appropriate to mention this Convention here for it emphasizes the notion of coastal in- terest in adjacent fisheries. As will be indicated further below, one of the major consequences of effective recognition of freedom of the seas as international law doctrine is that the fishery resources of the high seas are regarded as open to all who may wish to exploit them and, in converse statement, that no one political authority is competent to regulate or limit access to them except by its own nationals. The only acceptable method in customary international law for extending conservation regulations to international fisheries, those which lie beyond state territory, is that of securing agreement among all the states whose nationals exploit them. If one or several states believe it is necessary or desirable to regulate a fishery, their efforts can be frustrated if another state, whose nationals engage in substantial exploitation, refuses to cooperate. Under such circumstances the conservation ef- forts of the cooperating states can be wholly vitiated by the non-complying fishermen. It was to meet this problem, at least partially, that the Conservation Convention was adopted. The scheme devised provides that under certain conditions, precedent and antecedent, the coastal state can unilaterally 5 promulgate certain conservation regulations for a stock or stocks of fishes if it is unable to secure agreement thereon from other states whose nationals also exploit the stocks. This is not the place to examine this Convention in detail,10 but it is advisable to note that this permission to extend unilaterally conceived regulations is accompanied by provi- sion for what amounts to compulsory international adjudica- tion for determining whether the necessary conditions have been met. Again without elaborating, it is notable, to this observer at least, that the requisite conditions for permissible unilateral regulations are sufficiently demanding that many states, especially those without extensive scien- tific establishments in fishery matters, will find it diffi- cult to justify their efforts at regulation. Perhaps it is no coincidence that of the four Geneva Conventions it is this one which has enjoyed the least favorable response and which is still not in effect as of this writing (February, 1966). THE CONTINENTAL SHELF Probably the international law relating to the continental shelf is relatively more familiar to non-lawyers than any other aspect of sea law, for, as the saying goes, this is where the action is. However, the Convention on the Conti- nental Shelf, despite both its brevity and the apparent simplicity of its solutions, merits close examination. The Convention seeks to accomplish several tasks: (a) es- tablish the authority of the coastal state over the adjacent shelf or submarine region; (b) define the limit of the shelf; (c) describe the resources subject to coastal disposition; and (d) provide for the accommodation of some of the various conflicting uses to which the shelf can be put. The follow- ing seeks to describe the provisions on these points. (a) COASTAL AUTHORITY Convention Article 2(1) provides: "The coastal state exercises overthe conti- nental shelf sovereign rights for the purpose of exploiting it and exploiting is natural resources. Perhaps the most important observation to be made about this provision for present purposes is that, contrary to some ap- parently informed opinion, it does not sanction the inclusion of the continental shelf (as defined in the Convention) as part of national territory. What it does accomplish is to establish that the coastal state has "sovereign rights" over the shelf for assuring exploration, and exploitation, of the natural resources to be found there. The competence thus conferred is not all-embracing and, in particular, it does not appear to include the full range of the legislative authority of the coastal state. (b) THE LIMIT OF THE CONTINENTAL SHELF There is wide understanding that the Convention definition of the continental shelf does not coincide with the usual geolog- ical conception. The shelf comprises, according to Article 1, 6 "the seabed and subsoil of the submarine areas adjacent to the coast but outside the area of the territorial sea, to a depth of 200 metres or, beyond that limit, to where the depth of the superjacent waters admits of the exploitation of the natural resources of the said areas; .... " The former of these two criteria is, indeed, often accepted as the conven- tional definition of the shelf, but as is known this is only a very rough approximation and has been said to give "a some- what restricted and oversimplified view of the character and location of the shelf edge."11l In any event wherever the 200 metre contour line may fall on the floor of the sea adjacent to a mainland or island coast the area within it is considered to be the shelf for the purposes of the Convention. Quite plainly the main element of concern in this definition is the second part which is open-ended and permits expansion of exclusive coastal authority outwards as technology permits exploitation in deeper waters, including those beyond the edge of the shelf in its geological conception. (c) RESOURCES SUBJECT TO EXCLUSIVE COASTAL DISPOSITION The Convention provision for mineral resources is straight- forward: all mineral and non-living resources of the seabed and subsoil fall within the exclusive control of the coastal state and cannot be explored or exploited without its consent. Animal resources are defined as those "living organisms be- longing to sedentary species, that is to say, organisms which, at the harvestable stage, either are immobile on or under the seabed or are unable to move except in constant physical con- tact with the seabed or the subsoil." The range of resources within this conception has been the subject of controversy among various states. (d) ACCOMMODATION OF CONFLICTING USES Some years before the 1958 Geneva Conference convened it was realized that it would be required to make provision for various uses of the shelf and the waters above which could interfere with coastal control over mineral resources or with which the latter could interfere. The following is a very general account of the principles adopted to meet this problem. In the first place, the adoption of the phrase "sovereign rights" for a particular purpose, as the description of coastal authority, does not by itself accord the coastal state primacy in the event of conflict with other uses. It was very clearly understood that there were limitations on coastal authority when conflict arose or seemed imminent. Several articles seek to spell out the general standards for accommodating these conflicts. One of the major problems perceived at Geneva, indeed perhaps the most important contemplated at the time, was that some states might seek to use the expression "sovereign rights" over the shelf for a particular purpose as a base for extending coastal rights over the fisheries in the waters above. What- ever considerations might be adduced In favor of this method of allocating these resources, the Convention provides no sup- port for it. Article 3 was adopted with the object of pre- cluding any interpretation of the Convention to this effect: 71 "The rights of the coastal state over the continental shelf do not affect the legal status of the superjacent waters as high seas, or that of the airspace above those waters.I" By referring to the companion Convention on the High Seas, which offers definition of the rights of all states in high seas areas, it may be seen that this Article preserves not only freedom to fish in the shelf waters (for those prey not included within the definition of natural resources in Article 2 of the Convention) but also freedom of navigation. At the same time it was widely understood and agreed that mineral exploitation of the shelf could not be stultified by absolute insistence upon non-interference with other activities in the area. It was necessary, therefore, to offer some guide- lines on the extent of permissible interference with these other activities. On this point the Convention speaks in very general terms indeed, because, no doubt, it was thought impos- sible to furnish more specific directions for the myriads of' possible situations. Article 5(1) thus provides: "The exploration of the continental shelf and the exploitation of its natural resources must not result in any unjustifiable interference with navigation, fishing or the conservation of the living resources of the sea, nor result in any interference with fundamental oceano- graphic or other scientific research carried out with the intention of open publication." It is apparent that this provision distinguishes the treatment of conflict with navigation, fishing and conservation on the one hand and scientific research on the other. For the former, interference is permissible if justifiable, though no criteria of justification are offered, but in the latter case no inter- ference at all is permissible. In the case of navigation, a later article makes clear that in some situations, namely in "recognized sea lanes essential to international navigation," no "installations or devices" can be established. Scientific research is also singled out for special treatment in a later article. Apparently acting on the belief that oil exploration activities may take the guise of scientific re- search (as is evidently possible), the Convention provides that "the consent of the coastal state shall be obtained in respect of any research concerning the continental shelf and undertaken there." This same article seeks to spell out con- ditions under which the state "shall not normally withhold its consent." The high-level generality of the terms employed perhaps provide some warning of the probability of future dif- ficulties In receivjng coastal consent to research in conti- nental shelf areas., THE HIGH SEAS Beyond the accepted territorial sea limits of the states, the waters of the oceans are referred to as high seas. In this area the ships of all states are regarded as free to move about for all legitimate purposes without interference by other states except as may be authorized by international law. Such author- ization, some of which we have previously mentioned, is not by 8 any means frequently available but on occasion it is. An illus- trative occasion that is still regarded by some as controversial involved the conduct of hydrogen bombs tests by the United States, resulting in the closing of hundreds of thousands of square miles of open ocean to the use of other states. Generally speaking, however, the major principle of the law re- garding the high seas is that it is open to the use of all and that no single state or group of states can subject it to ex- clusive control for any prolonged period of time. In terms of past resource exploitation this has meant that fishing vessels can engage in operations without deference to the law of any state except the state of registration. Insofar as the ocean floor is concerned the only consequential traditional use is that of cable-laying and this too is regarded as protected by the principle of freedom of the seas. In turning from this very brief, and necessarily incomplete, sketch of previous decisions, a few preliminary remarks are necessary about the nature of the legal process, and then the focus is turned upon certain new or intensified uses, actual or contemplated, which may give rise to international legal disputes. It should go without saying that the previous experience in resolution of disputes, recapitulated above as the present "status" of the law, is available either for avoiding future disputes or for assisting in decision of such controversies as cannot be avoided. Nevertheless it is necessary to emphasize, in view of what appears to be misunderstanding on this point, that we need not assume this previous experience is useless in newer contexts; although contexts are always in flux, this con- dition attends all legal decision-making. Neither are we re- quired to entertain the notion that past decisions can be simply extrapolated into the future in the blind belief that our herit- age of law is always adequate when new conditions of interaction confront us. This conception of simple extrapolation of the past without regard to potentially significant change in condi- tions is also foreign to modern conceptions of legal process. It would seem to be especially alien when considering a body of law as ancient as the international law of the sea. Hence the task involved here is the familiar one of confronting past formulations of authoritative policies with emerging and different problems not directly anticipated by previous decision- makers and of asking whether new prescriptions and policies, or different interpretations of old, should be devised to promote basic community goals. To raise questions of this kind or to suggest new or different solutions than those previously found acceptable does not at the same time require, or imply, the necessity of adopting any particular procedure or method for seeking these solutions. If observers express concern about the potential inadequacy of the previous international law of the sea, there is no need to see in this an urgent call to impetuous action. But failure to make preparation for possible action seems most unwise, especially since important initiatives in international law could be taken by any state or group of states. This latter consideration, incidentally, helps place in appropriate per- spective the expressed position of the United States State 9 Department which is that the Department is unaware of a need for study of any international law or relations problem relat- ing to the development of the natural resources of the ocean.13 Although adoption of the stance of the ostrich is regretable in the primary department of the government responsible for foreign policy, it is at least fortunate that this dismal attitude ap- pears to be unique to this department. The numerous possibilities in developing ocean exploitation could pose such a variety of more or less important legal problems that some selectivity is necessary in discussing fu- ture prospects. Exercising more or less arbitrary choice, the following remarks center upon mineral exploitation, fisheries, and potential claims to acquire portions of the ocean floor for purposes other than mineral exploitation. A. MINERAL EXPLOITATION The question of international legal arrangement for hard mineral exploration and exploitation is much discussed by a variety of people and no doubt much studied by corporate coun- sel. Insofar as lawyers are concerned, however, there are almost no published statements or reports assessing the situation--this, of course, is because the lawyers directly involved are either house counsel or retained by clients and neither of these groups is likely to become vocal about his specific problems. It is left, apparently, primarily to the academic lawyer, and to the engineers and fishermen, to speculate on these matters in public. This state of affairs is unfortunate and probably could be rem- edied if the lawyers, and their clients, thought they could benefit from freer communication. In my opinion they could both benefit from more open discussion and avoid the dangers of dis- closing proprietary information. TF-matters remain as they are, the hazard is that public consideration of the legal problems involved in ocean mineral mining will be too abstract to shed much light. Perhaps speakers at this M.T.S. meeting will begin to remedy these difficulties. The initial issue regarding ocean minerals has been framed as whether such resources may be appropriated by a single state (or group which will be protected by some state) or whether they must be regarded as beyond such appropriation i.e., they must be open to all who may wish to exploit them.14 This form of query may not seem particularly useful since it appears to pose as exclusive alternatives two courses of action which can, in fact, be employed simultaneously. That is to say: the mineral resources of a particular, relatively small, ocean area could be regarded as subject to exclusive appropriation while, at the same time, all other areas are open to similar exclusive appropriation by anyone who has the capacity to exploit and who does engage in exploitation within a reasonable period. If some form of limited exclusive appropriation is likely to eventuate, It seems useful to query, further, whether these ocean resources are to be acquired for the gain of a single group only, namely the appropriators, or whether this aspect of ocean exploitation can be made directly to benefit the world community as a whole. The alternatives posed here are whether the protection and regulation of ocean mining is to emanate from each state which has public or private groups engaging in this venture, or whether ocean mining is to be subject to organ- ized public international regulation or, even, exploitation. The possibility last mentioned, that of having the exploitation 10 of hard minerals under ocean waters carried out by a public international group, is the least likely to eventuate. Since it seems such a remote possibility there is no need now to assess whether this system would be desirable according to certain criteria. In longer term perspective, however, such inquiry could be most worthwhile. Another possibility is much more frequently recommended, that of allocating these resources for exploitation by individual public or private entrepreneurs through an established inter- national organization. Thus, sometimes it is said that the United Nations is the appropriate body to exercise the authority to allocate these resources and to derive some financial benefit therefrom. The assumption underlying this approach is, appar- ently, that all states would join together and by agreement con- fer the authority on the United Nations, or on an especially constituted organization devoted to this specific purpose, to prescribe the conditions under which private or public groups could acquire rights to exploit and undertake mining an processing operations. There are, of course, a great many permutations in organization and in detailed procedures which can be imagined if an international solution of this kind were to be adopted. Assessing these numerous possibilities is be- yond the purpose of this discussion, however it is desirable to call attention to the financial aspects of this suggestion for it is often assumed both that large sums of money would then become available to the international institution and that it is desirable to support the U.N., as presently constituted, in this way. There is, in the first place, good reason to doubt that these ocean resources represent a great source of wealth for the U.N. or a special international organization. For the foreseeable future, at least, it is probable that the problems of making ocean mining competitive with conventional land min- ing will preclude imposing substantial royalties or fees upon these enterprises. But assuming there might be some, even substantial, income for the international group, the existing political situation in the United Nations suggests that any international arrangement, especially if the United Nations is involved, must insure that the new wealth is expendable only for non-political purposes. The recent dispute over the financing of peacekeeping operations, which is still not satisfactorily resolved, and the continuing great disparity in the General Assembly between the voting power of the majority and their control of resources necessary to support the operations of the U.N. which they authorize by their votes are the principal factors leading to this conclusion. It is presently inconceivable that either side in the Cold War would acquiesce in a United Nations which has an independent source of finances and which can be dominated by a large group of states with little power or wealth of their own.15 Hence, If the international organization approach were otherwise de- sirable, it must be carefully designed to cope with this dif- ficulty. The pointhere is not to suggest that this difficulty is insurmountable but merely that hopes for stronger internation- al political institutions are unrealistic if based on the expecta- tion of income from this source and that ocean development is not likely to be expedited by looking to existing international in- stitutions. In discussing future prospects so far as the legal environment for ocean mining is concerned, the role of the observer is distinctly a modest one, especially in connection with predic- tions about what will happen. Lawyers directly concerned with 11 clients' problems are far better equipped with the information upon which predictions can be based. And officials with govern- ment responsibilities would seem natural sources of advice on the future. But, as noted above, the private lawyers do not ap- pear to be talking, at least in public, and the U.S. State De- partment, the critical executive agency for this purpose, takes the position that this is not a problem worth investigation. Should the question of protection of ocean mining soon become an urgent one the principal issue seems to be whether there are any current international law prescriptions which might be use- ful and effective. Some possibilities warrant consideration. It would be possible to begin with the proposition that these resources, insofar as they are beyond the jurisdiction and con- trol of any state, have much the same legal characteristic as other high seas resources, such as the ocean waters and fish. This would mean that mineral resources of the ocean floor are common property, open to exploitation by all comers and subject to appropriation by the first taker. Given certain conditions it seems very possible that initial mining ventures could be made secure through this approach. The critical condition is that exploiters are likely to be relatively few, at least ini- tially, so that in practical effect there would be no need to protect against encroachment by others upon the area subjected to exploitation. The only problem, and it would not seem dif- ficult, is in protection of the operation itself, presumably the ships from which equipment would be operated. Even assuming the ship were to remain virtually stationary, or move about only very slowly,-there are ample legal principles available for In- suring non-interference. The flag state, the United States pre- sumably but it could be any state, is entitled to assert sole authority over the craft and the ships of other states are not competent to exercise any control over the ship. Possibly it would be contended that ships of this type, serving primarily as platforms for conducting operations on the bottom below and therefore moving about very little, would constitute hazards to Navigation and impede free navigation by them. This does not seem to be a serious matter. We already permit the emplacement of thousands of drilling rigs and platforms in areas of the high seas and the accommodation made necessary between these instal- lations and shipping is regarded as wholly compatible with a realistic conception of freedom of movement on the ocean. Assuming the prospects for intensive exploitation of ocean areas made it seem likely that conflicts would arise over ac- quisition of rights, the notion of common property might be modified and made the basis for protecting the mining enterprise. If, as John Mero asserts, the mining venture requires an invest- ment in a particular area, because the mining equipment itself or the processing machinery m ust be tail ped to suit a particular location or a particular kind of nodule,1 then some kind of ex- clusive appropriation must be asserted by the enterprise or on its behalf by a state. As noted above this would require some modification of the notion of the common property characteristic of the resources. At least small parts of the total resources would have to be regarded as subject to exclusive appropriation. But as many have observed it is now believed that the mineral resources occur over so vast an area that for practical purposes open access would still be preserved. The removal of a small area for exclusive acquisition by one exploiter would still leave immense areas open to others. 12 If this approach were desirable as a means of promoting use of these resources the question remains about how it is to be ac- complished. Here too we have some experience to build upon. We are all familiar with the procedure employed to lay claim to the important resources of the continental shelf, namely by means of a unilateral proclamation by the President of the United States. It seems to be quite feasible to utilize the same method for acquiring control over high seas mineral re- sources in specific areas. The details of such a proclamation depend, of course, on the needs of the projected enterprises. The direction and extent of the claimed control over the re- sources of an area would have to be enunciated, as well as the conditions under which the enterprise would have to be operated in coordination with other uses of the areas concerned. The limits of the legal conception of the continental shelf are of course relevant in disucssing ocean mining operations. As mentioned above, the Convention on the Continental Shelf con- tains an open-ended definition which contemplates that the coastal states' limited sovereign rights will expand outward as technology permits exploitation to expand outward. The question this raises is at what point the coastal state must cease reliance, if it must cease reliance, on the Convention in asserting a claim to hard mineral resources and base its claim upon some other method of allocating them. Despite the literal wording of the Convention there are insufficient grounds for regarding it as authorizing unlimited expansion of coastal control outward. In the first place the policies which were sought in the convention rested upon the notion that the contiguity of the shelf to a particular coastal state engaged its interests in higher degree than those of other states. Ef- ficiency of exploitation, the economics of the enterprise and the impact of nearby off-shore activities on the coastal state's society were all thought to support the assumption of exclusive control by, or its grant to, the coastal state. At some point as activity moves outward and away from any particular state these factors lose their cogency as indicia of a need for con- trols in a particular state identified as coastal. Because no determinable line is clearly indicated by the factors mentioned, the solution to the dilemma may have to e in terms of purely arbitrary designation, as, for example, of the 1500 or 2000 foot contour line. Many difficulties in this supposed solution are rather easily discerned and principal among them is that states are not likely to be willing to agree on limits of ex- clusive control without knowledge of what it costs to do so. In other words, until we secure more accurate knowledge of the ocean environment states will be reluctant to concede a limit on their exclusive control. It may be helpful to note in this connection that this conven- tion provision can usefully be read in the context of the kinds of exploitation the Conference was concerned about. It is plain, if summary records yield such evidence, that the Con- ference was concerned with only one type of exploitation, oil- drilling from surface installations. The two preparatory docu- ments produced for the Conference, both by Dr. H. W. Mouton, from the Netherlands, focussed almost solely on the technology of oil exploration and exploitation.17 Indeed it is made ex- plicit that hard mineral exploitation was not even considered as a bearing on possible expansion of the shelf limit: 13 "In view of a certain fear of an ever outwards- moving boundary line of the legal 'continental shelf an inquiry was also made into the ques- tion whether the ocean floor contains any ex- ploitable minerals. The answers indicate that the sediment carpet covering most parts of the ocean floor does not contain minerals in any concentration worthwhile exploiting. "ln one place manganese ore has been found, but since this is available on land in sufficient quantity, exploitation from the ocean is not necessary and would not pay. The sediment carpet, being extremely thick, will in most places make exploitation of layers underneath impossible. In the few places where the sediment is thinner or non- existent, formations may be found with pros- pects of exploitation. Intrusions, such as the Mid-Atlantic Ridge, might have mineral deposits associated with them. The depth will, however, be an insurmountable obstacle for exploitation for a long time to come, quite apart from the commercial prospects which seem non-existent."lo These passages from the main preparatory document for the 1958 Geneva Conference are not offered to affirm the statements made therein but to provide additional support to the infer- ence drawn from the summary records that the Conference was not concerned with the aspects of mineral exploitation that cause some disquiet today. One final comment regarding ocean mining derives from the possibility that the relative proximity of a port may have a bearing upon the choice of exploitable deposits. If assurance of continued access to a particular port is important for a specific undertaking it would appear to be prudent to consider that access by foreign vessels to ports is not a matter of right unless explicit agreement to a right of entry is secured from the state concerned. Since most attention, so far as deep sea mining is concerned, focuses on the tropical Pacific it could be wise to pay particular heed to political develop- ments in this area and, especially, to the possibilities of complete independence for some of the island communities. The transformation of political status from colony or self-govern- ing territory to complete independence could conceivably have repercussions for mining operations dependent upon port fa- cilities in the new states. B. FISHERY EXPLOITATION Changes in the legal environment are but one influence among many having significant impact upon the conduct of fishing operations and it is doubtful if the demands leading to new legal claims have run their course. The major legal change, past and future, consists of the expansion in the areas over which states assert exclusive rights of access to fisheries. In seeking this expansion, supposedly necessary to protect local fishermen from more efficient competitors, states utilize three principal techniques either separately or in combination: adopting the straight baseline system for de- limiting internal waters and territorial sea with the objective 14 of enlarging the former and extending the latter over areas hitherto open to free exploitation, widening the area claimed to be within the territorial sea, and establishing a contig- uous zone for fishing which extends beyond the territorial sea. It should be emphasized that these techniques can be used simultaneously to reinforce each other and in combina- tion the expansion of exclusive access can be considerable. Although all these methods have the common effect of per- mitting greater exclusive access, each has different conse- quences in other respects, especially that involving use of a new straight baseline system. The effect of this extends to the delimitation of all other boundaries of state authority in the ocean, territorial sea, contiguous zones, and, in some situations, even the continental shelf. It is not possible to make confident general assertions about the compatibility of specific applications of these methods with international law. The 1958 Convention on the Territorial Sea does contain the provision, noted above, permitting the use of straight baselines in certain circumstances, hence states do have criteria for assessing the lawfulness of partic- ular systems. As seems obvious the various systems adopted will all be different and each must necessarily be appraised independently of the others. The one certain proposition to be advanced is that even with the criteria available disputes over particular claims are very probable. This probability approaches near certainty for certain claims, such as those by archipelago states, such as the Philippines, to draw base- lines connecting the outermost islands and to declare all waters within the lines to be Internal waters. Although this specific illustration refers to a situation for which the Territorial Sea Convention does not provide, i.e., for states composed entirely of islands, this Philippine claim may be contrasted with the new English baseline system which, while it greatly expands internal waters, does not seek to use the outermost islands as base points for the system. If this had been done, additional very large high seas areas would have been converted into internal waters. The expansion of exclusive access by means of creating special fisheries limits beyond the territorial sea is becoming so com- mon that it suggests a definite trend toward recognition-that such zones are in accord with international law. The same may be said for limited enlargements of the territorial sea beyond three miles. It is not necessary to regard either of these extensions as desirable policy to judge that their frequency records the emergence of new, or at least somewhat different, principles of international law. Taking the position that these specific methods of seeking to allocate marine fisheries exclusively to one community are not desirable as a general policy should not be understood as sup- port for the proposition that these resources should continue to be regarded as open to competitive exploitation. The con- ditions that seem likely to prevail in the future appear to assure that the fisheries will be under even more intensive exploitation, by far more sophisticated methods, than they are now. Even if the potential food resource in the ocean is never realized to the full, and it need not be assumed that it would be desirable even to try to achieve such a level of exploita- tion, more and more states are likely to exert more and more effort to reap benefits from the fisheries. It seems fair to 15 say, as have a great many more expert observers, that the major problem attendant to this development will be that of achieving an equitable allocation of the fisheries through some means of controlling access to them. This, I take it, is what is meant by the recurrent pleas for more effective international "management" of these international resources. The immensity and complexity of this task is not underestimated. Indeed the contemporary expansion of exclusive fishery limits by the means mentioned above provides contemporary evidence both that states regard the prospect of an allocation scheme as hopeless and prefer to rely instead on crude methods of excluding competitors in order to be assured of some part of the resource and that these states are unwilling, and perhaps unable, to engage in a competitive scramble for the resource. This expansion also possibly testifies to the belief that if a system of allocating high seas fisheries can be devised, the expanded exclusive fishing area gives the state concerned an assurance of a greater part of total resource available. It is appropriate to refer in this connection to the 1958 Conservation Convention since some contend that in this instru- ment we now have the means of achieving proper regulation of the resource. The most interesting point to be noted about these recommendations is the complete absence of explanation about how this treaty is to be used for the purpose of allocat- ing resources. Nothing in the treaty even remotely concerns itself with positive criteria for allocation; to the extent the treaty is relevant for this purpose it will be a hindrance not a help. Of course it can be said, and has been said, that by requiring negotiations between coastal and non-coastal states, supported by the sanction of compulsory arbitration, the treaty provides an incentive for agreement upon allocation of particular stocks. Perhaps the treaty will work this way, but if states value unimpeded access to particular stocks, or better access than the coastal state proposes, they may be willing to take their chances of defeating the proposed coast- al conservation measures in the subsequent arbitration or of obtaining a recommendation from the tribunal for more favorable measures. If, as the Convention directs, the tribunal can ap- prove only those measures which are non-discriminatory, in form and in fact, possibly the complainant state may feel there are advantages in litigation. Furthermore if the pro- posed measures do in fact effect an allocation of resources and are somehow approved by the arbitral tribunal, the latter will of necessity employ standards for allocation derived from some source other than the treaty since none are provided therein. If these events transpire, the contribution of the Conservation Convention can only be characterized as indirect, as providing a mechanism by which management criteria can be created on a case-by-case basis. A few concluding remarks are in order about prospects for the development of criteria for allocation of these resources. First, unless previous experience is vastly improved upon the prospects are dismal indeed. Only two of the multilateral in- ternational conservation agreements contain provisions for al- locating a resource and one of these, in the North Pacific treaty between Japan, Canada and the United States, reflects a rather unique situation which is characterized most importantly by the unusual circumstances attending the conclusion of the agreement. Moreover, even apart from doubts about this applica- tion of the abstention principle, the viability of this arrange- ment is now also in question. If prospects for continuation of 16 the North Pacific treaty in its present form are not bright, only frail expectation can be entertained for wider adoption of this principle of allocation. The fur seal treaty is the other agreement establishing a method of sharing the yield but no one pretends that the factors accounting for this ar- rangement occur generally. Among the bilateral treaties the salmon agreement does provide for a division of the catch but if the value of this experience, as observers remark, is to emphasize the importance of the homogeniety of the states con- cerned as a factor accounting for the agreement on dividing the catch then all we have learned is that agreements on al- location are going to be very difficult to achieve in the great majority of situations. Second, this relative absence of useful experience is an ac- curate barometer of the amount of attention devoted to the problem. If the dispute potential of conflicting demands for access to fisheries is as high as some think, then the lack of study of this problem, academic, industrial and especially governmental, is at best extremely regrettable, and at worst disgraceful. Some of this neglect is understandable since the state of knowledge of the resource requires improvement and investment in this task is also a priority matter. But in accounting for what is, I believe, an overemphasis on biologi- cal research into fishery exploitation in comparison to in- quiry into political, social and economic elements, a major explanation is found in the unwillingness, until recently, of the biologists to concede that their approach was not the ex- clusive remedy. This particular obstacle has probably been largely overcome in the last decade but we still await signif- icant increase in the resources committed to study from the wider perspectives mentioned. There are some signs, at least, that awareness of this problem is now spreading. The recent elevation of the Fisheries Division to a more prominent and prestigeful position within FAO and the recognition in FAO of the importance of economic considerations is promising. The Bureau of Commercial Fisheries now devotes more attention to international economic aspects. The academic world too, in- cluding law schools as'well as economic departments, has begun to place emphasis on this matter of allocating international resources. And within the internation fishing commissions it is evident that the focus of attention has widened somewhat in recent years to embrace considerations other than the physical state of the resources. Even with these improvements, however, the effort is still grossly inadequate in relation to the potential losses both from continued inefficient exploita- tion and from what might be unnecessary controversies. C. ACQUISITION OF THE OCEAN FLOOR FOR PURPOSES OTHER THAN MINERAL EXPLOITATION Virtually all that has been written or, at least published, about legal aspects of the ocean floor in the regions beyond the continental shelf is in terms of mineral exploitation and there is little or nothing beyond casual comment to be found on the issue of claims to an area for other or more comprehen- sive purposes. No involved process of thought is required to discern the reasons for this. The ocean floor has been used, to be sure, for a century for one specific purpose, the laying of submarine cables, but the legal questions involved in this activity have never involved any claim to exclusive use. The legal problems which did emerge were concerned only with the 17 conflict between fishing operations and the cables and these issues were resolved almost a century ago and partially re- iterated in the Convention on the High Seas in 1958. The latter not only incorporates certain provisions of the 1884 Convention on the protection of cables, without prejudice to the continuing effectiveness of other provisions, but explicitly records in Article 26 that "All states shall be entitled to lay submarine cables and pipelines on the bed of the high seas." The Convention on the Continental Shelf also makes provision for these instrumentarities on the shelf in seeking to provide for freedom of use compatible with coastal rights over the shelf. But even apart from mining operations, previously discussed, the recent dramatic changes in conditions of access to the deeper regions, and contemplated progress in overcoming the many obstacles, suggest that it might be worthwhile to devote some thought to more extensive claims to the floor, ranging from complete incorporation as national territory to more limited assertions, but still exclusive, of usage and authority. Initially, at least, the regions which appear most attractive for active utilization are the large number of seamounts found in all the oceans, since the acquisition of information and knowledge concerning the environment in shallower regions is now being actively pursued both in the United States and else- where. And it seems reasonable to believe that the more acces- sible ocean features, which would include some seamounts, will be employed before serious attention is devoted to deeper areas. Apparently not only are there large numbers of seamounts but the possibilities of productive use are numerous, for one com- mentator has declared that "The number of applications to which a manned seamount base could be put is limited only by the imagination of marine scientists. "19 The reference, it may be emphasized, is only to manned bases, although unmanned bases are not at all excluded. For purposes of the present discussion the most significant employment of seamounts would be for military activities, a category that includes a considerable range of operations with varying impact on expectations regarding the kind of state authority required vis-a-vis other participants in ocean use. The military potential of seamounts perhaps could extend to the emplacement of weapons systems or equipment indispensable to the operation of systems located elsewhere, including the waters surrounding the base. Other uses would appear to be considerably less strategic in nature such as the installation of experimental devices or temporary habitations, the conduct of research for direct military benefit, and the construction of shelters housing communications and navigation equipment. It may be a complicating factor, or even one simplifying the supposed legal problems, that some uses, especially those last mentioned, contribute not only specifically to military operations but also to general ocean development. Still other military applications might be the operation of repair facili- ties and supply depots. And suggestion has been made that strategically located seamounts could be useful in missile and space operations, as in permitting recovery of nose-cone and payload components. Perhaps it might also be considered desir- able to use such submerged bases for some tasks that could be performed as well on land but which for special reasons would benefit from a submerged location. 18 Scientific research, only remotely useful to military opera- tions, could be promoted on seamounts in a number of produc- tive ways because of unique conditions there. One inherent, valuable characteristic of seamounts stems from the obvious fact that it is enveloped in water and the further fact, ac- cording to recent report, that the water serves as a barrier to background radiation. From this it is concluded that 'experimentsin radiology, genetics and contamination could be conducted without heavily shielded laboratories."20 The depth of seamounts below sea level is another feature of the situation that might be turned to good account since this permits emplacement of remote data collection systems in a safe location below the turbulent surface waters and currents which wreak havoc with research buoys stationed therein. One observer also anticipates that "Geophysicists and oceanographers would have a stable, quiet platform from which to conduct long- term investigations of submarine acoustics, seismic sea waves (tsunamis), ^picroseismic activity, heat-flow and other physical phenomena.)"2T Investigations in marine biology and no doubt numerous other disciplines could be pursued effectively from stations on seamounts. I. POTENTIAL CLAIMS Perhaps the most important factor affecting the kinds of claims to exclusive use and regulation to be expected consists of the specific purpose or purposes for which a portion of the ocean floor is to be devoted. Certain of the military usages could very well entail the claim to subject an area to the most comprehensive and exclusive control a state could exert. Thus, for the most strategic uses, encompassing at least weapons systems or associated equipment, it is at least con- ceivable that states would regard it as important to occupy the area and to treat it for all practical purposes as part of national territory. Such treatment would embrace the ex- clusion of non-national vehicles either from the immediate area and perhaps from access to a surrounding region suitable for surveillance. If the exclusion were to extend to surface waters the possibility of controversy would probably be great- ly magnified. Other military uses might be regarded as less critical and necessary protection might be secured by lesser assertion of authority, considering the latter in terms of the scope of the activities affected, or the extent of the area involved, or the duration of any authority claimed. Some research aimed at producing direct military benefits might be conducted with efficient advantage even though other activities were carried on in the same area. General scientific research, such as a manned oceanographic laboratory or an unmanned installation of instruments, would appear to generate claims to exclusive authority in terms of the kinds of research conducted. Some types might require quiet and isolation, requiring extensive assertion of author- ity and others might not. 2. FACTORS RELEVANT TO POLICY The basic policy question is whether it is desirable, from the standpoint of the general community interest, to permit states 19 to claim exclusive use and authority over specified parts of the ocean floor and, if so, what degree of such use and author- ity should be permitted. The suggestion is that such acquisi- tion ought to be considered lawful when the claim is reasonable in light of all relevent factors in the context. Some of the factors which are considered to lend support to this conclusion may be considered briefly. The more important factors involve the scope of the competence claimed, such as those pertaining to the objectives sought; the characteristics of the situation in terms of the location and extent of the areas concerned, and the duration of the claim; the degree to which others are sought to be affected; and the outcome of the activity involved. The purpose or objective sought by the claimant state would appear to have an important, sometimes determinative, bearing an the permissibility of acquisitions. Certain goals, though pursued by unilateral claim to submarine territory, may be rather widely shared among many participants, including states, private associations and individuals. For example, the estab- lishment of a subsea installation as a laboratory for certain scientific experiments or as a strategically located oceano- graphic research facility could promote purposes sought also by groups associated with different states. Even if exclusive use is necessary and even if certain other activities in the region are precluded, the benefits sought from such use do not pertain exclusively to the claimant state. The general propbsi- tion this expresses is that the degree of exclusiveness or in- clusiveness in the specific objectives of acquiring a seamount should be weighed carefully in assessing the reasonableness of a claim. As mentioned previously, seamounts are expected to be found in all the oceans but they are at this time known to occur in most intensive concentration in the Pacific. In current esti- mate the 1400 known seamounts in the Pacific are but ten percent of the total in that basin alone. The significance of these numbers for policy is in the possibility that the regions for potential acquisition may be very numerous, especially for un- manned stations. Many seamounts are probably less appealing as sites for manned installations due to the problems posed by depth. But for either type of station the acquiring state might be enabled, because of the large number of possible sites, to exercise considerable selectivity and to choose on the basis of criteria related to the general interest in the use of the ocean. Specifically, selection of sites could be affected by the remoteness of a region from consequential con- flicting, or potentially conflicting, uses and by the relative proximity of various submarine regions to the territory of the claimant state. A wide range of choice might also indicate the importance of selecting locations which are remote from particular, non-claimant states. One factor relevant to the lawfulness of a particular claim to acquire a submarine area might be the degree of provacation implied in the selection of a site adjacent to another state. The extensiveness of the area involved includes both the size of the seamount or other region and the extent of any additional water area over which control is sought. Claims to seamounts with small surface area might be looked upon more favorably 20 than a claim to a very large part of the ocean floor, espe- cially if superjacent uses are wholly or partially precluded. Although seamounts may never reach a large size, so that the acquisition of territory is limited to localized areas, it may still be important whether the claim extends to the waters above the seamount or region. States are more likely to accept claims to exclusive use of the floor than those pertaining also to the waters above. The principal reason, mentioned below also, is that the latter would be more likely to affect other uses. A particular claim may vary a great deal in terms of its dura- tion, from assertion of permanent authority (though the degree of authority may be limited) to a temporary demand of a few weeks or months. It seems rather obvious that this feature of a claim may have significance when related to possible impacts upon the activities of others. In the beginning of ocean ex- ploitation, the phase we are now in, states may look with askance upon claims of indefinite duration, for these, if rec- ognized, could ultimately entail highly undesirable interfer- ence with uses presently unforeseen. However, when other factors are weighed in combination even permanent claims might be adjudged reasonable. The kind and degree of interference with others explicitly or implicitly demanded by a particular claim is of prime importance in appraisal of its reasonableness, as well as for general con- clusions about the policies at stake in this context. Obvious- ly claims to exclusive use which seek to displace only such other hypothetical use as might simultaneously be made of the identical location raise fewer difficulties than claims in- volving exclusion of other activities in a wider area. Assum- ing that preclusive effects are not in fact involved, the former type of claim would appear to promote policies of en- couraging full use and at the same time not offend any other policy. The greater the degree of impact on other productive activities the larger the burden of persuasion on the claimant state to justify the reasonableness of its claim. One of the reasons for suggesting it is lawful to acquire regions of the ocean floor is that it seems likely that particular claims will not have impact on other uses. The outcomes of emplacing stations, manned or unmanned, upon the ocean floor will probably differ for the various partici- pants. The use of these areas for military purposes may be, or may not be, deeply disturbing to the opponents of the claimant state in the sense that the opponent feels deprived as a result of the threat perceived. Security is a value which many believe, unfortunately, can only be acquired at the expense of someone else. But, on the other hand, and despite this view regarding security, even military installations on the ocean floor may have more inclusive beneficial impact than merely protection of the claimant state, since the stability such in- stallations could conceivably assist in creating would extend to all potentially involved. Certain kinds of floor stations are easily imaginable which might produce nothing but good for everybody, even though the immediate benefits accrue to a particular community. The extent to which outcomes have widely sharable benefits is obviously important for policy. It is even more important if such an outcome is explicitly sought by the claimant. 21 One final point may be conclusive on desirable policy con- cerning acquisition of the submarine regions of the high seas and that is the degree of analogous acquisition in past practice and the likelihood that states will in fact acquire such areas in the future. The alacrity with which states have allocated the continental shelves among themselves and the fact that mineral exploitation of the shelf must neces- sarily on occasion displace other uses provides a clue to the attitude that seems likely to be adopted as other submarine regions become accessible for productive use for mineral ex- ploitation and other types of activity. There is the major difference, o- course, that the shelves have been allocated to states only for particular purposes and not for all pur- poses, i.e., the shelves are not part of national territory. However, the regions beyond the shelf which may be open to effective use, other than for mining, are not thought to be extensive and in view of their remoteness more far-reaching claims to authority may be regarded with equanimity. Insofar, at least, as states determine that great benefit can be realized from exclusive acquisition of a portion of the floor beneath the high sea, and that such acquisition imposes only minor burden on others, it seems unrealistic to expect them to refrain from doing so and from protecting and supporting that claim. REFERENCES *The author acknowledges assistance in aid of research and publication from the Mershon Social Science Program of the Mershon Center for Education in National Security, The Ohio State University. I. The range of potential problems is extensive and this paper is limited to but three general subjects: hard mineral mining, fisheries, and territorial claims to the ocean floor. On the first two of these, recent detailed studies are avail- able: Mero, The Mineral Resources of the Sea (1965); Johnston, The International Law of Fisheries (1965); Christy and Scott, The Common Wealth in Ocean Fisheries (1965). For suggestions of other potential legal difficulties see Burke, Ocean Sciences, Technology and the Future International Law of the Sea (1966). 2. It is now recognized that the traditional notion, still not completely dispelled, that only states are subjects of international law is inaccurate descriptively, and furnishes neither desirable guidance for policy nor reliable basis for projecting future events. 3. A convenient summary of recent legislative efforts in this direction, and commentary thereon by informed persons, is in Hearings on National Oceanographic Program Legislation, Subcommittee on Oceanography of the House Committee on Merchant Marine and Fisheries, 89th Cong., Ist Sess. (1965). 4. For contemporary writing upon some of these problems see the Proceedings of the 1966 Law of the Sea Institute, scheduled for publication in 1967. 5. See, generally, for comprehensive discussion organized as this paragraph suggests, McOougal and Burke, The Public Order of the Oceans (1962). 22 6. For an extensive collection of national and inter- national documents, official governmental statements, views of writers, and assorted memoranda, bearing on the Geneva Conventions see 4 WHITEMAN, Digest of International Law (1965). 7. This right of access, apart from specific agreement, arises when a straight baseline system incorporates certain waters as internal. See discussion on this system below and see also Convention on the Territorial Sea and Contiguous Zone, Article 5. 8. Anglo-Norwegian Fisheries Case, 1951 I.C.J. Rep. 116. 9. At both the 1958 and 1960 Geneva Conferences the United States departed from this traditional position to support a 6-mile territorial sea, under certain conditions. When these proposals failed to obtain the necessary two-thirds approval for Conference adoption, the U.S. announced continued adherence to a 3-mile territorial sea. See, generally, 4 WHITEMAN, op. cit. supra note 6, at 88-137. 10. See,generally, McDougal and Burke, op. cit. supra note 5, at 968-1007; Johnston, op. cit. supra note I, at 344-57, 411-30. 11. Lyman, A Review of Present Knowledge Concerning the Continental Shelves of the Americas, in Geological Survey Bulletin 1067, p. 29 (1958). 12. See, for more detailed discussion, Burke, Technology and Ocean Law, 1966 Proceedings, Law of the Sea Institute. 13. See letter, dated May 3, 1965, from Douglas MacArthur II, Assistant Secretary of State for Congressional Relations to Chairman Bonner, House Committee on Merchant Marine and Fisheries, in Hearings, op. cit. supra, note 3, at 102. 14. See Burke, supra note I, at 53-4. 15. See, generally, Padelford, Financing Peacekeeping: Politics and Crisis, 19 Int. Org. 444, and especially 454 (1965). 16. Mero, op. cit. supra note 1, at 291-92. 17. Mouton, The Breadth of the Safety Zone for Installations Necessary for the Exploration and Exploitation of the Natural Resources of the Continental Shelf, U.N. Doc. No. A/Conf. 13/26 (1958) and Mouton, Recent Developments in the Technology of Ex- ploiting the Mineral Resources of the Continental Shelf, U.N. Doc. No. A/Conf. 13/25 (1958). 18. Id. at 24. 19. Palmer, Seamounts Will Act as Platforms, Undersea Tech- nology, August, 1965. 20. Ibid. 21. Ibid. 23 GEOLOGICAL METHODS FOR LOCATING MINERAL DEPOSITS ON THE OCEAN FLOOR K. O. Emery Woods Hole Oceanographic Institution ABSTRACT Geological considerations of the potential mineral resources on the ocean floor indicate that primary igneous mineral deposits are unimportant as com- pared with sedimentary mineral deposits. This difference is due to the thick cover of Tertiary sedimentary strata on most continental shelves and the gen- eral lack of deep weathering and erosion of igneous and metamorphic rocks in the few places where they are exposed on the continental shelves. The chief sedimentary mineral resource of the ocean floor at present and prob- ably in the future is oil and gas, which are almost restricted to thick marine sedimentary sequences. The only other minerals that have been recovered commercially are the heavy concentrates of placers (tin, diamonds, iron, gold) and cheap supplies of shell and other sediments in shallow nearshore areas. Much interest has been focused on ocean-floor deposits of phosphorite and manganese oxide, but the low quality of the deposits and the uncertainties in the costs of mining delay their possible exploitation. INTRODUCTION This Marine Technology Society contains many members who are great opti- mists about the potential of the oceans to supply mineral resources in quantity at costs that are competitive with resources from the land areas of the world. Perhaps the optimism is an occupational hazard of those whose livelihood is the selling of devices or services for marine exploration or exploitation. The truth probably lies between the beliefs of these optimists and the beliefs of the less well represented pessimists who have found neither gold nor diamonds in their thousands of ocean-floor samples. Let us attempt to set some general limits on our expectations of the ocean's bounty by using geological methods. Other limits are set by political and legal restrictions (Shalowitz, 1962) and by mechanical and economical factors that will change in time. Tangible resources of the ocean can be grouped into biological, chemical, and geological ones. Practically impossible to evaluate are other aspects such as transportation, recreation, military, and supply of water for desalination. Figure 1 shows that biological resources are presently the most exploited ones, and that during 1964 the United States harvested only about six per cent of the value of the world's crop of fish, mammals, and algae from the ocean. It also Contribution No. 1791 of the Woods Hole Oceanographic Institution 24 $ o 9 0 1 2 3 4 5 6 7 KIND BIOLOGICAL CHEMICAL GEOLOGICAL UNI TED S TA TES REST OF WORLD Figure 1. Value of marine resources recovered from the ocean during 1964. Data are from Gaber and Reynolds (1965a) and Weeks (1965a, 1965b). S fo9 o10 20 30 TYPE I LAND METALS LAND METALS SEA FLOOR NON-METALS LAND EXCEPT FUELS SEA FLOOR COAL LAND SEA FLOOR LAND OIL AND GAS SEA iFLOOR- I I I ! F'X7'YA UN/ TED STA TES REST OF WORLD Figure 2. Value of geological resources mined during 1964. Data are from D'Amico (1965), Gaber and Reynolds (1965a), and Weeks (1965a, 1965b). 25 recovered less than one-third of the salt (NaC1) but nearly all of the magne- sium and bromine that was chemically extracted from sea water. This report, however, is supposed to be concerned with the geological resources that are on the sea floor or far beneath it. In this field the United States recovered 20 per cent of the total world value, with United States' capital responsible for much of the remaining 80 per cent--such as products of the submarine oil fields of Lake Maracaibo and the Persian Gulf. The most important of the geological products obtained from the ocean floor adjacent to the United States is oil and gas ($700 million for 1964) and the closely associated sulfur from offshore salt domes ($15 million) (Fig. 2). Shell deposits dredged from shallow bays yielded $30 million in 1964. In proportion to recoveries from land, the offshore products are relatively small, but they are rapidly increasing in quantity and value. Ocean-floor recover- ies from other areas of the world include besides oil and gas the more exotic tin, diamonds, iron, and gold--but altogether their value was only $10 million during 1964. Why have the resources from off the United States not included diamonds and gold? Why does oil and gas dominate on most continental shelves? How does the type of resource control the method of geological ex- ploration? In order to answer these questions we should consider the geology of mineral deposits. ORIGIN OF MINERAL DEPOSITS Mineral deposits are classififed here in a way slightly different than the usual geological way, as an adaption to the marine environment. Most fundamental of all are the primary igneous mineral deposits, because some can be mined directly as ores and others have served as original sources for other kinds of ore deposits. These primary igneous deposits include magmatic segregation, pegmatites, deep-moderate-and-shallow veins, and contact metamorphism. All are virtually restricted to intrusive igneous and associated metamorphic rocks. Outcrops of these kinds of rocks are known at only three places on the continental shelf of the United States: the Gulf of Maine, Monterey Bay, and off the Golden Gate in California (Fig. 3). At none of these places have samples exhibited valuable mineralization. Many primary mineral deposits on land are too low grade to be mined as ores until after they have been enriched by weathering and erosion. Enrichment may take two forms: (1) solution and concentrated redeposition of the val- uable mineral (copper, silver) accompanied by erosion of some of the worthless residue left at the surface, or (2) solution and removal of the worthless mater- ial leaving at the surface a residual concentrate of the valuable mineral (iron, bauxite, diamonds). Both enrichment processes require many million years of exposure to weathering and erosion; thus, they are much less likely to be important on the ocean floor (even on the continental shelf) than on the long- exposed land areas. In fact, most igneous rocks that have been dredged from outcrops on the ocean floor are so fresh that any incipient weathering is a curiosity. A mineral deposit somewhat related to secondary concentration by solution and redeposition is produced by long-distance transportation and redeposition within sedimentary strata by ground water (lead, uranium). Although fresh ground-water has been found in drilled samples of sedimentary strata 100 km at sea (Bunce and others, 1965), its probably low hydrostatic pressure head must cause especially slow circulation that greatly reduces the likelihood of the development of such mineral deposits on the ocean floor. 26 Three kinds of direct sedimentary origin for mineral deposits are common. One is the placer deposit (gold, tin, diamonds) that is formed where streams or waves and currents cause heavy minerals to be selectively deposited in isolation from relatively worthless lighter minerals that are carried away. The minerals must previously have undergone extensive weathering and ero- sion from their original position within igneous and metamorphic rocks. Because the ocean floor lacked sufficient weathering and erosion, few if any placer deposits should have originated on it. Instead, placers on the ocean floor should be extensions of well-known ones on land--such as the gold of Alaska, the tin of Malaya and Cornwall, and the diamonds of Southwest Africa. Placers are unrelated to the composition of their substrate, but they occur only near their primary igneous or metamorphic source rocks. A second kind of sedimentary mineral deposit is a chemical or biochemical precipitate. The best example is manganese oxide in the form of nodules and crusts on the ocean floor. The manganese is independent of the type of substratebeing found on or in deep-sea sediments and on volcanic rock and limestone of seamounts. An essential condition for its formation is a slow rate of deposition of detrital or biogenic sediments because of their diluting effect. Two other sedimentary mineral deposits are phosphorite and glauco- nite, but the origin of each is complicated in some ocean-floor deposits by the inclusion of some material from reworked older deposits. Nevertheless, all three materials (manganese oxide, phosphorite, and glauconite) can be primary sedimentary deposits formed by precipitation from sea water. Their depth ranges overlap, but manganese nodules and crusts are best known from the deep-sea floor, and phosphorite and glauconite are mainly from the outer part of the continental shelf and the top of isolated banks. The last and most important sedimentary deposit to be considered here is oil and gas, which begin as organic matter grown largely by phytoplankton near the ocean surface. The organic matter is partly transformed through inges- tion by small and large marine animals and by bacteria. Eventually it is buried deep beneath detrital and biogenic sediments where further modifica- tion to oil and gas is followed by migration into structural or stratigraphic traps from which it may be released to the earth's surface through seeps or drilled wells. Alteration of the organic matter also causes most of the sulfate in the associated brines to be converted into elemental sulfur; deposits of this sulfur associated with salt domes can be melted by injected steam and pumped to the surface. In summary, the ocean floor is primarily a depositional region in which weath- ering has been insignificant and erosion minor in comparison with the possibly several kilometers of total weathering and erosion on land (Gilluly, 1964). Supergene enrichment or residual enrichment of primary igneous mineral depos- its should therefore be far less important on the ocean floor, even on the continental shelves, than on the continents. Even the unenriched primary igneous mineral deposits are likely to be deeply buried under a blanket of Late Cretaceous to Recent sediments that covers most of the shelves off the United States (Fig. 3) and probably the shelves of most of the rest of the world (Fig. 4) except where it was removed by Pleistocene glaciers. Accord- ingly, let us turn our attention more to the sedimentary mineral deposits than to the igneous ones. 27 1G- IQr- s0 A M L Figure 3. Simplified geological map of the United States and its adjacent continental shelves. Solid black indicates areas of exposed intrusive igneous and associated metamorphic rocks; cross- hatching indicates areas of marine Tertiary sedimentary strata whether exposed or covered by later sediments. From Goddard (1965). AkRA Figure 4. Simplified geological map of all continents. Symbols are the same as for Figure 3, but the geology of the shelves is omitted because of inadequate data. Sources are Beyschlag (1929), Director of the Geological Survey of India (1959), Goddard (1965), Hamilton (1963), Isakov (1953), Lobeck (1942), Lombard (1963), Nalivkin (1955), Stose (1950), Tectonic Map Committee, Geological Society of Australia (1960), and Warren (1965). 28 SAND AND GRAVEL Probably the simplest sedimentary deposits are those of sand, gravel, and shells. In areas of high population concentration these materials are needed for construction, earth fill, road material, and some minor miscellaneous purposes. About $890 million worth was mined in the United States during 1964 according to D'Amico (1965, Table 1). Only a small percentage came from the ocean floor, because of easier availability from stream valleys and older strata; however, Gaber and Reynolds (1965a, 1965b) reported the recov- ery of $30 million of shell from offshore--probably almost entirely from shallow bays of Florida, the Gulf of Mexico, and California. In addition, many new building sites are made by filling parts of salt marshes with dredg- ed sediment, but the value of the sediment is difficult to compute owing to the concomitant intent to deepen channels for navigation through other parts of the marshes. In some countries (Israel and Tordan, for example) sand for making concrete blocks has been mined so extensively that some beaches have virtually disappeared. In order to avoid similar losses of United States' beaches, the Coastal Engineering Research Center (U. S. Army) contracted for surveys of suitable construction sand and gravel farther offshore during 1964-1965. Extensive sampling of the surface of the continental shelf off the Atlantic coast by a joint undertaking of the U. S. Geological Survey and the Woods Hole Oceanographic Institution revealed a blanket of relict sand covering almost the entire width of the shelf (Fig. 5) (Emery, 1965). Relict gravels also are present locally (Schlee, 1964). The sand and gravel were deposited during times of glacially lowered sea level when large quantities of sediment were contributed to the ocean and when waves and currents were able to win- now out most of the clay and silt, leaving the coarser material as a sort of crude placer. Similar relict sands have been found on the continental shelves off the Gulf and Pacific coasts of the United States and off Brazil, China, Israel, and other countries (Emery, 1961). Surface samples and bottom photo- graphs provide the best data for locating the sands and gravels, but vibro- coring or drilling, supplemented by seismic reflection profiles are needed for determination of thicknesses. Mining and transportation should be cheap, commensurate with mining costs on land that permit the sand and gravel to be sold at about $1/ton. As the population along the coast increases (such as for the coming megalopolis between Washington, D.C. and Boston) demand for offshore supplies of sand and gravel probably will increase markedly. Concentrations of heavy minerals such as gold, tin, diamonds, and platinum are more classical types of placer deposits than are ordinary sand and gravel. They require much more wave and current energy to be transported than do the quartz and feldspar that comprise the bulk of sand deposits. Thus, most valu- able heavy mineral deposits form in high-energy shore zones. Changes in sea level during deposition caused the heavy minerals to be distributed in a thin and discontinuous blanket deposit interbedded with sand and gravel or lying just above bedrock. The main contribution that geology can make to the dis- covery of heavy-mineral placers is through knowledge of source areas and inferences about direction of movement in the shore zone. Evaluation must depend upon coring or drilling, coupled with seismic measurements of thick- ness of overlying sands and gravels. 29 TABLE I VALUE OF GEOLOGICAL RESOURCES MINED FROM THE OCEAN FLOOR DURING 1964 IN COMPARISON WITH THE VALUE OF THE SAME RESOURCES MINED ON LAND1 $ �o6 FROM OCEAN FLOOR FROM LAND UNIVTED REST OF UNITED REST OF RESOURCE STATES WORLD STATES WORLD SAND, GRAVEL, SHELLS 30 ? 860 ? IRON 0 0.7 800 4500 GOLD O 0 50 1500 TIN 0 5 0.02 600 DIAMONDS 0 4 0 7 PHOSPHORITE 0 0 160 215 MANGANESE OXIDE 0 0 3 420 OIL AND GAS 700 2900 10,500 17,000 SULFUR 15 0 100 140 iGABER AND REYNOLDS (1965b), WEEKS (1965a), AND D'AMICO (1965) 30 45 80 65' a 75� I I I 70 4 5 PORTLAND BOSTON (: NEW YORK 40 40� PETROLEUM WASHINGTON. 35-. 35' PETROLEUM PHOSPHORITE 30..t : . MANGANESE NODULES 30� . _ 30 oMIAMI )0 500 KM 80� 7I I I� I I 75� 70o Figure 5. Distribution of the most favorable areas for some potential mineral deposits off the Atlantic coast of the United States. 31 PHOSPHORITE Phosphorite, a complex calcium phosphate containing some fluorine, has long been used as a source of phosphate for fertilizer and chemicals. During 1964 phosphorite valued at $160 million was mined in Florida, Tennessee, and Idaho (and adjacent Montana, Utah, and Wyoming). At the present rate of mining, more than a thousand years' supply is present on land in the United States. A major part of the cost per ton at the point of use is for freight charges. If phosphorite can be mined from the sea floor near the point of use, the cost of mining can be greater than on land and yet the operation can be profitable. To-date, however, no commercial production from the ocean floor has been reported. Phosphorite was discovered in samples dredged from Agulhas Bank off Africa by H.M.S. Challenger in 1873 (Murray and Renard, 1891, p. 391). In 1937 it was found in samples from the tops of banks and locally from the outer parts of the mainland and island shelves off California by Dietz, Emery, and Shepard (1942). Subsequently, it was found off Florida (Gorsline and Milligan, 1963). In these areas (Figs. 5 and 6) and others it occurs as pellets, nodules, and crusts ranging up to about 60 cm in length and 75 kg in weight. Few analyses show P205 greater than 30 per cent, whereas the P205 in most of the phosphorite being mined on land is 31 to 36 per cent (Mero, 1965, p. 58). Prospecting for phosphorite can be guided by the known control exerted by rate of phosphate deposition and rate of dilution by detrital sediments. Pre- cipitation appears to be fastest in sea waters having a high concentration of dissolved phosphate--generally areas of great upwelling which support high concentrations of phytoplankton. The areas of greatest upwelling corres- ponding with deposits of phosphorite lie above shelves at mid-latitudes on the eastern sides of oceans (Fig. 7). Related high-phosphate waters occur in east-west trending belts at both low and high latitudes, but phosphorite deposits are not associated, probably because of the great depth of the ocean floor below these zones. The areas of upwelling are characterized by low rainfall on adjacent lands and absence of large rivers; thus, the rate that detrital sediments are contributed to the ocean is not great. A further de- crease in the rate of deposition of detrital sediments is produced by the topographic isolation from the sediment sources by offshore banks. After potentially rich areas of the ocean floor are selected on the basis of up- welling and isolated topography, the next step is field prospecting. Because phosphorite probably is restricted to a thin layer on the ocean floor, surface sampling is adequate. The best tools are large dredges and clear bottom photographs, perhaps supplemented by underwater television. Data provided by these tools are probably adequate to establish the volume of the deposit. At present, however, the question of profit in mining depends upon the costs of ocean-floor mining and of beneficiation, or processing, of the deposits. Estimates of these costs vary so much that o~inion is strongly divided about whether the ocean-floor deposits can be competitive with the land ones (Mero, 1965). One commercial test off southern California was aborted by the presence of an associated naval ordnance dump. We await the results of other tests with interest. MANGANESE OXIDE Manganese largely for metallurgical purposes is presently in short supply in the United States. Only $3 million worth of manganese was mined in this country during 1964, in comparison with about $420 million from the rest of 32 ---- ~ ----X~ ~SEA FLOOR OFF SOUTHERN CALIFORNIA PHOSPHORITE u VI, PROBABLE Figure 6. Distribution of phosphorite off southern California. From Emery (1960, p. 69). Figure 7. Most favorable areas for ocean-floor deposits of phosphorite on the basis of continental shelves associated with upwelled water rich in dissolved phosphate and absence of diluting sediment from rivers and glaciers. 33 the world. Imports during 1964 amounted to about $100 million worth of ores averaging more than 35 per cent manganese (DeHuff, 1965). Because of in- sufficient domestic production, the government offers a subsidy amounting to 50 per cent of approved exploration costs. Nodules of black manganese oxide have been known for about one hundred years to occur on the ocean floor. In fact, some of the best descriptions and pictures of the nodules were published in the reports of the famous Challenger Expedition of 1872-76 (Murray and Renard, 1891). The nodules from the ocean floor are widespread as a surface or near-surface deposit, but they are not very rich in manganese. Mero's (1965) 181 analyses for worldwide samples average 18 per cent manganese; those for the Blake Plateau off the Atlantic coast of the United States average 13 per cent of total weight. Only six of the analyses contained more than 35 per cent of manganese. For all analyses silicon averages 8.1 per cent. The usual method of extraction by chemical reduction allows silicon to withhold about twice its weight of manganese; thus, most or all of the manganese must be considered a waste product of the nodules until a better method of extraction becomes economi- cal (Institute of Marine Resources, University of California, 1965, pp. 13-1 to 13-29). According to Mero (1965), the associated 0.2 to 2.0 per cent of copper, nickel, and cobalt may justify the mining of manganese nodules, but these concentrations correspond to only marginal or low-grade ore deposits. Manganese nodules and crusts are widespread on the deep-ocean floor, appearing in many photographs and samples by American, Soviet, and British expeditions. They are concentrated at the surface but do occur at depths of at least a few meters (Bender, Ku, and Broecker, 1966). The origin of the deposits is not well known, thus their distribution cannot be inferred from origin but only by empirical methods. These methods fail to predict the pat- terns of distribution and concentration, and so recourse must be made to dredges, large grab samplers, corers, and cameras. Using such devices, Pratt and McFarlin (1966) outlined in detail an area of manganese oxide on the Blake Plateau (Fig. 8) that previously was sampled by Mero (1965) and others. The middle of the area has a pavement-like concentration of crusts, and it is surrounded by an annular area in which nodules are concentrated. Phosphorite nodules present at the landward side of the area of manganese oxide may be coincidental--a result of proximity to the known phosphorite deposits on the adjacent continental shelf and the gentle slope between the shelf and the Blake Plateau. Probably detailed mapping of nodules and crusts of manganese oxide in other oceanic regions will reveal distribution patterns that are different but perhaps as complex as that of the Blake Plateau. Whether the nodules can profitably be mined in any region is uncertain, but the author is pessimistic about the matter. OIL AND GAS Most of the world's oil and gas comes from Tertiary marine strata. These strata underlie coastal plains of all continents, and where the geology is known, they thicken seaward beneath the adjacent continental shelves (Fig. 3). This thickening increases the likelihood of future discoveries of oil and gas resources on the shelf within suitable structures or stratigraphic traps. Most present production is from seaward extensions of structures originally dis- covered on land (southern California, Lake Maracaibo, Persian Gulf), or from structures having a distribution pattern related to similar structures previously discovered on land (salt domes off Louisiana and Texas). In only a few 34 I I o I 0 I 0 33� =Area of manganese pavement o 0 7 \\Area of phosphate nodules o // Area of manganese nodules 0 A Camera stations o Dredge stations 0 DEPTH I AMETERS 0 0 321 '0 0-e '' ,t / o �� 3 790 78 Figure 8. Distribution of manganese oxide crusts and nodules off Georgia and Florida. From Pratt and McFarlin (1966). 35 3, instances (Australia, Persian Gulf) has production developed from ocean- floor discoveries of structures unrelated to those of the adjacent land. Wells on the ocean floor cost considerably more than wells on land; thus the prospecting for suitable structures is more rigorous than .on land. The chief geophysical method is a form of seismic profiling, commonly supple- mented by magnetic or gravimetric surveys. Final tests require actual drill- ing and examination of the strata. Both geophysical and geological studies must be detailed and closely spaced because of the small percentage of the continental shelf that is occupied by individual structures. This Society probably has no particular interest in the results of such de- tailed studies as are necessary to identify and delimit potential oil-bearing structures, but it may like to see the results of a general seismic reflection survey of the entire Atlantic coast of the United States. Forty-four profiles made at right angles to the continental shelf (Uchupi and Emery, in press) reveal a thickness of 200 to 800 meters of Tertiary strata beneath the contin- ental shelf (Fig. 9). The beds continue farther seaward beneath the contin- ental slope and locally beneath the continental rise. Seaward growth of the continental shelf from 5 to 10 km between Nova Scotia and Cape Hatteras to more than 35 km in the area of the Blake Plateau off Florida and Georgia occurred during the Tertiary. The profiles also depict many buried erosional surfaces. Geological testing of the geophysical results was accomplished by a series of six holes drilled during 1965 off northern Florida to maximum depths of 320 meters into the bottom beneath maximum water depths of 1032 meters (Fig. 10). The bulk of the prism of sedimentary strata overlying basement rocks off the Atlantic coast is believed to be Cretaceous limestones and shales. Seismic refraction measurements summarized by Drake, Ewing, and Sutton (1959), Hersey, Bunce, Wyrick, and Dietz (1959), and Antoine and Henry (1965) re- veal major variations in the total thickness of these strata. Greatest thicknesses off New England occur in two trenches that may join to form a single trench south of Cape Hatteras. The ridge between the two trenches may contain minor structures and traps whose identification may lead to off- shore oil fields along the Atlantic coast. An extension of this ridge off eastern Canada is actively being explored by several oil companies. Other potential oil fields may be associated with large cross structures known off New York (Drake, Heirtzler, and Hirshman, 1963) and southwest of Cape Hatteras (Hersey, Bunce, Wyrick, and Dietz, 1959) (Fig. 5). At present, oil companies are producing annually about $700 million worth of oil and gas from the continental shelves off Louisiana, California, and Texas. Bonus payments,(leases), rentals, and royalties for this production have found their way into federal, state, and coastal community treasuries. Revenue to the federal treasury alone for the years 1960 to 1964 was $1,234 million, considerably more than the $469 million that was returned to the ocean in the form of support for oceanography during the same period (Fig. 11). One can confidently predict that future activities by oil companies will pro- duce a steady rise in the recovery of offshore oil above the present 16 per cent of the total number of barrels produced from all of the world's oil fields. Probably offshore production will rise to 25 per cent of the total during the next 25 years. 36 KM FROM SHELF-BREAK 34 118 i~~~~~~~~~o ~ ~ ~ 3 ~~~~- . ~~~~~~~~~~ 55 ~ ~ ~ ~ ~ ~ T T9 70' 137 DISTANCE IN KM o 1oo �' �� . 200 300 400 500 r0 . LO SEA LEVEL-- 4 I---T- w200 X600: LOWER EOCENE ~95881LO coO UPPER CRETACEOUS VERTICAL EXAGGERATION=222 X 1200 - LAND 1CONTINENTAL SHELF1 FLORIDA- BSLAKE PLATEAU IBLAKE AHATTERAS ESCARPMENT Figure 10. Results of drilling off Georgia by JOIDES (joint Oceanographic Institutions' Deep Earth Sampling program). See Bunce and others (1965) for additional details. Discovery of oil and gas accumula- tions must be based upon similar drill holes positioned according to results of geological and geophysical surveys. 38 1906 $ fo6 0 400 200 300 400 500 600 3I I I I I I 3 ' ' 4 - m BONUS (LEASE) ROYALTY, RENTAL 1955 *Z OCEANOGRAPHY BUDGET 6 7 8 9 5/YE AR 19601 4 1965 Z///?// ESTIMATED 6 ,,3,, PROPOSED I I I I I I Figure 11. Federal revenue from oil, gas, and sulfur compared with federal support of oceanography. From Conservation Division (1965) and Interagency Committee on Oceanography (1961, 1962, 1963, 1964, 1965). 39 CONCLUSIONS Mineral deposits on the ocean floor have been considered by many men as surrounded with a kind of mystery akin to that given all mineral deposits during medieval times. The fact that the deposits are covered by water should not blind us to the need for geological investigations to locate them. Elaborate instrumentation may help, but often it hinders, and it cannot sub- stitute for geological thinking based upon data obtained by conventional techniques. A good example is provided by oil companies that have been highly successful in their use of modifications of the same techniques and the same geological thinking that are used on land to locate oil fields on the ocean floor. Oil, gas, and associated sulfur dominate the inventory of successful recoveries from the ocean floor around the United States and off the coasts of other countries as well. The reason for the importance of oil and gas is the typical presence of thick Tertiary sedimentary strata be- neath probably most continental shelves. In addition, once the wells have been completed production of oil and gas requires little supervision unlike, for example, any form of strip mining. Most published lists of potential mineral resources of the ocean floor are dominated by heavy mineral placer deposits. These are real and some have been mined, but all are extensions of placers known on the adjacent land and derived from nearby igneous or metamorphic source rocks. Where suit- able source rocks are unknown on land, a search for heavy mineral placers on the ocean floor is unprofitable. Sand and gravel deposits also constitute a form of placer, because the originally accompanying silt and clay has been winnowed away; moreover, sand and gravel can be derived from many kinds of abundant source rocks. Though cheap per unit weight compared with dia- monds and gold, sand and gravel is probably a far more important mineral resource of the ocean floor owing to its abundance and general lack of cover. Phosphorite and manganese oxide are abundant as nodules and crusts in certain areas of the ocean floor, but only in thin blankets. In the author's opinion, their generally great depth of water and great distance from shore, coupled with the low concentration of the desired elements, are heavily weighted against profitable exploitation. .Engineering breakthroughs in effi- cient recovery from the ocean floor or the assignment of large subsidies can change this forecast, but improvements in methods of beneficiation of the material are more likely to bring vast low-grade deposits on land into competition. Primary igneous mineral deposits may be present on the ocean floor but prob- ably with little secondary enrichment. They are most likely to be found off coasts having abundant exposures of igneous and metamorphic rocks on land and where a cover of sediments or of sedimentary rocks is absent or thin. No continental shelves that have been well studied to-date qualify, but per- haps some shelves at high latitudes are worth field investigation because Pleistocene glaciers may have removed sedimentary covers. Nevertheless, if the rocks on the adjacent land contain no valuable primary igneous mineral deposits, a good hard look at the general geology of the ocean floor should precede expensive diamond drilling. 40 REFERENCES Antoine, J. W., and Henry, V.J., Jr., 1965, Seismic refraction study of shallow part of continental shelf off Georgia coast: Bull. Amer. Assoc. Petroleum Geologists, vol. 49, pp. 601-609. Beyschlag, Franz, 1929, Geological Map of the Earth, scale 1:15,000,000, 12 sheets: GebrUder Borntraeger, Berlin. Bender, M. L., Ku, Teh-Lung, and Broecker, W. S., 1966, Manganese nodules: Their evolution: Science, vol. 151, pp. 325-328. Bunce, E. T., Emery, K.O., Gerard, R.D., Knott, S.T., Lidz, Louis, Saito, Tsunemasa, Schlee, John (for JOIDES), 1965, Ocean drilling on the continental margin: Science, vol. 150, pp. 709-716. Conservation Division, 1964, Annual and accrued mineral production, royalty income, and related statistics (oil, gas, and other leasable minerals): U. S. Geol. Survey, 127 pp. D'Amico, KathleenJ., 1965, Statistical summary: Minerals Yearbook for 1964, U. S. Bureau of Mines, vol. 1, pp. 105-151. DeHuff, G. L., 1965, Manganese: Minerals Yearbook for 1964, U. S. Bureau of Mines, vol. 1, pp. 735-754. Dietz, R. S., Emery, K.O., and Shepard, F. P., 1942, Phosphorite deposits on the sea floor off southern California: Bull. Geol. Soc. America, vol. 53, pp. 815-848. Director of the Geological Survey of India, 1959, Geological Map of Asia and the Far East, scale 1:5, 000, 000, six sheets, Secretariat of the United Nations Economic Commission for Asia and the Far East, Bangkok, Thailand. Drake, C. L., Ewing, M., and Sutton, G. H., 1959, Continental margins and geosynclines: The east coast of North America north of Cape Hatteras: Physics and Chemistry of the Earth (Editors--L. H. Ahrens, Frank Press, Kalervo Rankama, and S. K. Runcorn), Pergamon Press, New York, vol. 3, pp. 110-198. Drake, C. L., Heirtzler, I., and Hirshman, J., 1963, Magnetic anomalies off eastern North America: Jour. Geophys. Research, vol. 68, pp. 5259-5275. Emery, K.O., 1960, The Sea off Southern California: A Modern Habitat of Petroleum: John Wiley & Sons, Inc., New fork, 366 pp. Emery, K.O., 1961, Submerged marine terraces and their sediments: Zeitschrift fur Geomorphologie, Supplement vol. 3, pp. 17-29. Emery, K. O., 1965, Geology of the continental margin off eastern United States: Submarine Geology and Geophysics (Editors-W. F. Whittard and R. Bradshaw), Proc. 17th Symposium of the Colston Research Soc., Univ. Bristol, April 5-9, Butterworth, London, pp. 1-20. 41 Gaber, N.H. and Reynolds, D.F., Jr., 1965a. Ocean engineering and oceanography from the businessman's viewpoint: Ocean Science and Ocean Engineering, Marine Tech. Soc. and Amer. Soc. Limn. and Oceanog., Trans. Joint Conf. 14-17 June 1965, Washington, D.C. vol. 1, pp. 128-148. Gaber, N. H., and Reynolds, D. F., Jr., 1965b, Economic opportunities in the oceans: Battelle Technical Review, vol. 14, no. 12, pp. 5-11. Gilluly, James, 1964, Atlantic sediments, erosion rates, and the evolution of the continental shelf: Some speculations: Bull. Geol. Soc. America, vol. 75, pp. 483-492. Goddard, E. N. (Chairman), 1965, Geologic Map of North America, scale 1:5,000,000, 2 sheets: U. S. Geol. Survey. Gorsline, D.S., and Milligan, D.B., 1963, Phosphatic deposits along the margin of the Pourtalbs Terrace, Florida: Deep-Sea Research, vol. 10, pp. 259-262. Hamilton, Warren, 1963, Antarctic tectonics and continental drift: Polar Wandering and Continental Drift: Soc. Econ. Paleontologists and Mineralogists, Sp. Publ. 10, pp. 74-93. Hersey, J. B., Bunce, E. T., Wyrick, R.F., and Dietz, F. T., 1959, Geophysical investigations of the continental margin between Cape Henry, Virginia, and Jacksonville, Florida: Bull. Geol. Soc. America, vol. 70, pp. 437-466. Institute of Marine Resources, University of California, 1965, California and use of the ocean: A planning study of marine resources: Prepared for the California State Office of Planning, October 1965: IMR Ref. 65-21. Interagency Committee on Oceanography, 1961, National Oceanographic Program, Fiscal Year 1962: Federal Council for Science and Technology, 27 pp. Interagency Committee on Oceanography, 1962, National Oceanographic Program, Fiscal Year 1963: Federal Council for Science and Technology, ICO Pamphlet No. 3, 31 pp. Interagency Committee on Oceanography, 1963, National Oceanographic Program, Fiscal Year 1964: Federal Council for Science and Technology, ICO Pamphlet No. 11, 67 pp. Interagency Committee on Oceanography, 1964, National Oceanographic Program, Fiscal Year 1965: Federal Council for Science and Technology, ICO Pamphlet No. 15, 50 pp. Interagency Committee on Oceanography, 1965, National Oceanographic Program, Fiscal Year 1966: Federal Council for Science and Technology, ICO Pamphlet No. 17, 73 pp. Isakov, I. S. (Chief), 1953, Morskoi Atlas: Ministry of the Navy of the U.S.S.R., vol. 2, plate 10. 42 Lobeck, A. K., 1942, Geologic Map of Europe, scale 1:5,000,000, 1 sheet: The Geological Press, Columbia University, New York. Lombard, Jean (General Coordinator), 1963, Geological Map of Africa, scale 1:5,000,000, 9 sheets, Association of African Geological Surveys, United Nations Educational, Scientific and Cultural Organization, Paris. Mero, J. L., 1965, The Mineral Resources of the Sea: Elsevier Publ. Co., New York, 312 pp. Murray, John and Renard, A. F., 1891, Report on Deep-Sea Deposits Based on the Specimens Collected during the Voyage of H. M.S. Challenger in the Years 1872 to 1876: Her Majesty's Stationery Office, London, 525 pp. Nalivkin, D. V., (Editor-in-chief), 1955, The Geological Map of the U.S.S.R., scale 1:5,000,000, 8 sheets: The Ministry of Geology of the U. S. S. R., Moscow. Pratt, R. M., and McFarlin, P.F., 1966, Manganese pavements on the Blake Plateau: Science, vol. 151, pp. 1080-1082. Schlee, John, 1964, New Jersey offshore gravel deposit: Pit and Quarry, vol. 57, pp. 80, 81, 95. Shalowitz, A. L., 1962, Shore and Sea Boundaries: With Special Reference to the Interpretation and Use of Coast and Geodetic Survey Data: U. S. Dept. Commerce, Coast and Geodetic Survey Publ. 10-1, vol. 1, pp. 209-276. Stose, G. W., 1950, Geologic Map of South America, scale 1:5,000,000, 2 sheets, Geol. Soc. America. Tectonic Map Committee, Geological Society of Australia, 1960, Tectonic Map of Australia: Scale 1:2,534,400, 4 sheets: Bur. Mineral Resources, Geol. and Geophys., Dept. Natural Development. Uchupi, Elazar and Emery, K. O., in press, Structure of the continental margin off the Atlantic coast of the United States: Bull. Amer. Assoc. Petroleum Geologists, vol. Warren, Guyon, 1965, Geology of Antarctica: Antarctica (Editor--Trevor Hatherton): Methuen & Co., Ltd., London, pp. 279-320. Weeks, L. G., 1965a, Offshore Oil: The Oil and Gas Journal, 21 June 1965, pp. 127-134, 138, 140, 142, 143, 145, 147, 148. Weeks, L. G., 1965b, World offshore petroleum resources: Bull. Amer. Assoc. Petroleum Geologists, vol. 49, pp. 1680-1693. 43 SELECTING AREAS FAVORABLE FOR SUBSEA PROSPECTING By V. E. McKelvey and Livingston Chase U. S. Geological Survey, Washington, D.C. Abstract Submarine mining technology is well enough developed to permit produc- tion of rich deposits of several minerals almost anywhere they can be found. The search for these exceptional deposits can be expensive, however, and it is desirable to narrow the target for prospecting by identifying areas favorable for their occurrence. Geologic and oceanographic principles are adequate to define some sub- marine provinces favorable for the occurrence of several important minerals, particularly those in two broad groups: 1) minerals genetically related directly or indirectly to sea water and 2) residual minerals of terrigenous origin. Most important among the first group are those related to upwelling nutrient-rich waters--phosphorite, oil, several minor elements, and oceanic salines--and for these many favorable areas can be defined from existing knowledge of oceanic circulation. Residual deposits include sand, gravel, gold, diamond, monazite, ilmenite, cassiterite and other resistates, and alumina-rich clays and other hydrolyzates. Some favorable provinces for these minerals can be defined from analysis of local source terrane, climate, geomorphology, and tectonics. A third group of minerals--high-grade, localized hot-springs deposits of manganese oxides,iron-sulfides, and other minerals--is also a target for prospecting but one more difficult to define; knowledge of submarine volcanism may help. The demonstrated utility of available submarine prospecting methods indicates that the incentive of a profitable target can be matched by the capability for finding it. Much can be accomplished by reconnaissance surveys, but full realization of the submarine mineral potential requires geologic mapping as a base for both prospecting and exploration. Inasmuch as the presently valuable mineral deposits are largely confined to the shelf environment, it would be desirable to extend systematic geologic mapping and related geophysical surveys over the continental shelves. Publication authorized by the Director, U. S. Geological Survey. 44 INTRODUCTION The potential mineral resources of the ocean and the rocks beneath it include dozens of minerals (Mero, 1965; Hess, 1965; Byrne, 1964; Pepper, 1958). For many of these, the prospecting problem is not as pressing now as mining, beneficiation, recovery, or utilization problems. With millions of square kilometers of the ocean floor already known to contain manganese nodules, and other large areas known to contain glauconite, calcareous ooze, or siliceous ooze, there is not much reason to be concerned about finding additional deposits of the same kind until economical means are found to recover and use those already known. The prospecting problem, however, is extremely important for most of the minerals that are now being produced from the sea bottom or that will be produced in the near future (for current production, see Gaber and Reynolds, 1965). For oil and gas, sulfur, and many placer minerals, extractive technology is already developed to the extent that they can be produced nearly anywhere on the shallower parts of the continental shelves from deposits of sufficient size and quality. And several less valuable materials, including sand and gravel, shells or other forms of calcium carbonate, salt, and phosphorite are or could be produced from sizeable deposits of good quality in areas where scarcity permits a higher cost. Even manganese could be produced economically now if deposits similar in quality and composition to those mined on land could be found on the sea bottom, for they would not present the difficult processing problems posed by the deep-sea nodules. In the practical world of marine mining, then, the problem of finding concentrations of minerals that can be produced at competitive costs is one of first-rank importance. Minable deposits of these valuable minerals are rare, and most of them are relatively small, even tiny in size compared with the extent of the terrane in which they occur. Fortunately, there are effective techniques and instruments for use in finding them in the submarine environment. Dredging and coring devices are now relatively well advanced, as are submarine photographic and television techniques. Means to allow the prospector to make direct observations on the sea bottom are rapidly developing. A wide variety of geophysical methods are also available for use in marine prospecting, and some of them are valuable as direct ore finders. The magnetometer and radiation detectors are already in this class, and McOulloh's (1966) recent work indicates that high-precision gravimeters may be useful in detecting anomalies that are produced by accumulations of oil and gas. Some of the oil companies are using scanning devices that measure hydrocarbon content of sea water as a means of identifying submarine petroleum seeps, and detectors for silver, gold, beryllium, and other metals are becoming available and may be adaptable for marine use. The success already achieved in submarine exploration for oil and gas, sulfur, tin, and diamonds demonstrates the utility of these field proce- dures and instruments in prospecting, and clearly shows that the incentive of a profitable target can be matched by the capability for finding it. The ocean, however, is a big place, too big to scan systematically even with direct ore finders. Moreover, in view of the difficulty and high cost of marine prospecting, the limitations of presently available extraction technology, and the unfavorable geologic character of large parts of the ocean floor, presently findable and workable deposits of many minerals are relatively much less abundant than on land. Those searching for presently minable subsea mineral deposits must therefore find effective means to cut the odds against discovery. One of the best ways to do this is to reduce the size of the prospecting target to the most favorable areas, and it is to this subject--the use of available data 45 and principles in selecting favorable mineral provinces--that we will devote our principal attention here. In particular, we will focus on three groups of minerals: 1) those that are genetically related to upwelling nutrient-rich waters, 2) residual minerals of terrigenous origin, and 3) localized hot-spring deposits of manganese oxide and other minerals. MINERALS GENETICALLY RELATED TO UPWELLING The process known as upwelling, in which deep, cold, nutrient-rich waters rise to the surface, produces a chain of chemical, biologic, and climatic phenomena that are reflected in a considerable variety of depositional products of direct or indirect economic importance, including phosphorite, oil shale, oil and gas, several saline minerals, sulfur, and a number of minor metals associated with phosphorite and black shale. Knowledge of this genetically related rock assemblage and of the processes involved has come partly from the study of the ocean and its present sediments (e.g., see Murray and Renard, 1891; Sverdrup et al, 1946; Dietz et al, 1942; Brongersma-Sanders, 1948, 1957) and partly from the study of fossil marine phosphorites and associated sediments (Kazakov, 1937; McKelvey et al, 1953, 1959; McKelvey, 1959, 1963; Cheney and Sheldon, 1959; Sheldon, 1964a). During the last several years, these relations have been successfully applied to the search for phosphate on land in several countries (Sheldon, 1964b), and they may be even more useful in marine prospecting. The fundamental processes and products are as follows (mainly repeated from McKelvey, 1963). The solubility of phosphate in sea water increases with decreasing pH and temperature (Sverdrup and others, 1946, p. 241 and 788), and for this reason it is most concentrated in deep cold waters. Nitrate, the other critical nutrient element in the sea, closely parallels phosphate in its distribution; to some extent silicate (a nutrient element for some organisms) does also (idem, p. 242, 245). Oceanic circulation, which mainly reflects atmospheric circulation brought about by solar heating combined with the rotation of the earth, deep plows the sea and brings these nutrient-rich waters to the zone of photosynthesis in local areas. In an idealized ocean, the main elements of the current system consist of a large circulating gyral in each hemisphere (fig. 1); water cooled in polar latitudes moves toward the equator along the east edges of the ocean, and water warmed in equatorial latitudes moves poleward along the west edges (see also Fleming 1957). In this system, cold nutrient-rich waters are brought to the surface in four situations: 1) where a current diverges from a coast, or where two currents diverge from each other. The effects of cold currents moving toward the equator in bringing cold phosphate-rich water along the coast are abetted by the seaward movement of coastal surface water that results from the combined effects of prevailing wind and Coriolis force, for as the surface water moves seaward, deep cold water wells up to replace it; 2) where two currents meet to produce turbulence; 3) along the west edge of poleward-moving density currents; 4) in high latitudes where highly saline water from the tropics tends to sink as a result of winter cooling. Pronounced climatic, biologic, and geologic effects accompany this deep plowing of the sea, especially in the areas of upwelling produced by divergence. The presence of cold waters along coasts produces coastal fogs and humid-air deserts. Some of the driest areas of the world are of this type--humid air, perhaps some hygrophytic vegetation, but no rain. The Peruvian and southwest African deserts are present-day examples. The naturally fertilized waters that lie alongside these deserts are the lushest gardens of the sea, for the upwelling cold waters support tremendous quantities of organisms (Sverdrup and others, 1946, p. 786-787; Ryther, 1953), 46 ~~~~.,1 900 Sr mx.ing E quatorial Curren g c Equtrd Current c 90o XX Turbulent mixing Upwelling caused by divergence //// o Mixing as result of Dynamically caused upwelling winter cooling FIGURE I. SURFACE CURRENTS IN AN IDEALIZED OCEAN, SHOWING AREAS OF ASCENDING, NUTRIENT-RICH WATER (See Fleming, 1957) 47 with diatoms and other phytoplankton at one end of the food chain, and fish, whales, and fish-eating sea fowl at the other. Blooms of dinoflagellates (red tides) and diatoms are characteristic biologic phenomena in upwelling areas, as are the mass mortalities of fish that accompany red tides and may be a consequence of them (Brongersma-Sanders, 1957). The geologic phenomena accompanying upwelling are perhaps most complex of all. Phosphate in the upwelling water becomes less soluble as the pH and temperature increase near the surface and is precipitated either inorgan- ically or biochemically. In either case, the mineral formed is apatite, a complex calcium fluorophosphate that characteristically also contains minor but perhaps commercially significant amounts of several elements, including uranium and rare earths. Because phosphate is a relatively minor constituent of sea water, concentrations of apatite only develop in the absence of diluting clastics and carbonates. This prerequisite is not uncommonly met, however, in areas of pronounced coastal upwelling for the waters are too cold for carbonate deposition and the aridity of the adjacent land does not favor a high influx of elastics. Some of the organic matter produced in the zone of photosynthesis is winnowed away and dispersed or destroyed by surface currents, but much of it settles to the bottom, producing reducing conditions even along the open sea (Brongersma-Sanders, 1948). The abundance of the organic matter and the reducing conditions favor the accumulation of oil, gas, sulfur, and several metals, particularly vanadium, molybdenum, zinc, and nickel. In this same general environment, silica is precipitated biochemically through diatoms, silico-flagellates, and sponges; carbonates are pre- cipitated either chemically or biochemically in warmer coastal waters; and salines may form in lagoons that extend into the adjacent deserts. And, of course, guano and guanotized rock are also characteristically associated with this environment. These several phenomena may be observed today in many areas of upwelling, especially those along the western margins of the continents, and nearly all the phosphate deposits known on the present sea bottom lie in such areas of divergent upwelling (fig. 2). The geologic effects are well illustrated by the Permian Phosphoria Formation and associated rocks in the western United States, and by many other phosphorite formations. For example, the sedimentary facies that are found in this environment are summarized in figure 3, which represents an idealized section of rocks deposited synchronously in the Phosphoria sea in Idaho and Wyoming. As shown there, dark carbonaceous shale typically grades shoalward into phosphatic shale, phosphorite, and dolomite; chert; several facies of carbonate rock; and saline deposits and light-colored and red shale. Epeirogenic movements cause these environments to shift laterally. As the sea transgresses and regresses the lateral sequence shown in figure 3 is produced, in whole or in part, in the same or in reverse order in vertical section; over the region as a whole shoalward facies overlap and intertongue with deeper water facies in vertical section. An example of such an intertongued sequence of sediments is shown by the reconstructed cross section of the Phosphoria Formation and its stratigraphic equiva- lents in figure 4. Some of the beds of the Phosphoria are oil shales, but in the main, petroleum is now found in the fringing carbonate facies, where it is believed to have migrated from the shale (Sheldon, 196) . As indicated in figure 3, the upwelling environment is significant in the origin of petroleum, not only in producing large quantities of source materials and creating the reducing conditions necessary for their preser- vation (Smith, 1954), but also in producing as facies equivalents the reservoir rocks and sealing beds necessary for the entrapment of petroleum. The assemblage of sediments illustrated in figures 3 and 4 is typical of marine phosphorites associated with strong, divergent upwelling, such as 48 ISO 160 f40 120 '00 so 60 40 20 0 00 40 60 so 100 100 140 lED ISO 40 A RED WATER, NO MASS MORTALITY X RED WATER, COINCIDING WITH MASS MORTALITY 60 ~~~~~~~~~~~~~~~~~~A MASS MORTALITY PROBABLY COINCIDING WIT" RED WATER 60 0 DIATOM OOZE (OR MUD; BROAD BANDS OF DIATOM OOZE IN ARCTIC AND ANTARCTIC REGION$ NOT INDICATED) UPINELLING WATER --PHOSPHATE DEPOSITS too 60 14010 100 soS 8 60 40 20 0 20 40 60 so 100 120 140 160 I SO Figure P. Distribution of upwalling water and rotated phenomena in modern oceans (modified Brongermam- Sanders, 1957, to Include date on the distribution of phosphate deposits). WEST EAST source beds 4 reservoir beds - -sealing beds- - -----osea level soo - - -- upwelling current - = - - - dark fossiliferou. fossiliferous pelletal alga onhydrite,ond = - =- - -- |phosphotic chaert limestone dolomite dolomite dolomite light-colored ond -_~-_-- ..-- .shale,' red shole -_-==_--j| phosphorite === I---~__~' ~ and dark carbonaceous dolomite shale Figure 3 -Lateral sequence of environments and sediments in the Phosphoria sea (Cheney and Sheldon, 1959). OUTHERN WESTERN WINO RIVER CENTRAL SOUTHEASTERN IDAHO' WYOMING MOUNTAINS WTOMING WYOMING _lg~ I. Z I G 2 S U;_."*-_, ................................. ....., k:.?f ... ~~' _tT|;':;~ ~' .!EXPLAATION 11[es., Egtta'.tel M=rmatio C.a hugwIte. MO*M= To l I d Vhg P l i i ~ i . ~JlaP 5. e . idets o .Pe~isa FCiue' udS t o neatonte oPark ee d eon Idhor Gn(Mcenle ndoher Phmphohont N aoisono st ec ole Figure4.-Stratigraphic relations of the Phosphorioa, Park City, and Chugwater formations In Idaho and Wyoming (McKelvey and others, 1959). 50rm~ occurs along the west coasts of the continents. Another phosphorite assemblage, consisting of phosphatic limestone or sandstone without associated black shale or chert, appears to form along the eastern margins of the continents. These deposits, illustrated by those of Miocene age in southeastern United States and the Receife area, Brazil, may have formed in areas of dynamic upwelling or turbulent mixing along the western edge of the warm currents that occur along the west side of the oceans (fig. 1). Alternatively, they may have been deposited in estuaries, similar to those of the present day along the coast of Georgia, where the phosphate content of the water is built to high levels by organisms that "trap" phosphate brought by rivers or by tidal exchange with the ocean (Pevear, 1966). Judging from the fossil record, primary deposits of this type are low grade; workable deposits are those that have been later upgraded by weathering and submarine reworking and even these are generally less phosphatic than those associated with divergent upwelling. These relationships have been successfully applied in recent years to the search for phosphate in several countries (McKelvey, 1963; Sheldon, 1964b), using both oceanographic and geologic clues. There are still promising possibilities for applying these relationships to prospecting on land, but they are equally applicable to prospecting in the marine environment. The localities in which phosphate has been dredged from the sea bottom (fig. 2) are prime prospects, of course, particularly those on the west coasts of the continents or in other areas of strong upwelling. Upwelling environ- ments in general are favorable, whether or not phosphate has already been reported from the sea bottom. Most of the areas of prominent upwelling have probably already been identified, but additions and refinements probably will be made as more knowledge of marine circulation is gained, and such future developments will be worth watching for their bearing on prospecting. Whether or not submarine phosphorite can be mined economically in close competition with land deposits is perhaps debatable, but for countries that do not have land deposits, those offshore should prove valuable. Chile is a prime example of a country that apparently has rather poor prospects for land deposits but excellent prospects for good deposits offshore. The critical question, as always with low-value deposits, is not whether submarine phosphorite can be produced for the world market but whether it can compete with world sources in the local market. Most of the phosphate dredged from the sea bottom thus far consists of nodules and crusts that contain a maximum of about 29 percent P205. Experience with fossil deposits tells us that this may be about the maximum grade expectable, for the somewhat higher P205 content found in many land deposits generally seems to be due to enrichment by weathering. Many of the occurrences of phosphate shown on fig. 2 probably will be found to consist of only a thin surface layer of crusts of nodules, too poor for profitable recovery except where better sources are far removed. In some areas, however, we should also expect to find submarine deposits of phosphate pellets a few feet to, rarely, several tens of feet in thickness, and in places, successive layers should be found beneath the sea bottom. Some phosphorite will be mixed with organic matter, some with diatoms and other siliceous organic remains, and some with sand. With regard to phosphatic sands, it is well to keep in mind that they can occur as beaches and bars. Phosphorite pellets have a density of about 3.0 and are concentrated as placers under favorable circumstances. The offshore bar near Santa Rosalia, Baja California (Wyatt, 1956) is a good example of such a deposit. The total phosphate content of such sands may be only a few percent, but the phosphate grains can be concentrated cheaply. This type of occurrence should be kept in mind in examining placers primar- ily valuable for other minerals. For example, phosphate is known to occur off the coast of Southwest Africa; do the diamond-bearing placers there also contain recoverable quantities of phosphate? 51 It is possible that saline deposits may be found at shallow depths beneath the sea bottom in some areas of upwelling, and it is also possible that potassium- and magnesium-rich brines may be found in estuaries and ground water in the coastal deserts adjacent to strong areas of upwelling. Such brines have been discovered in recent years in the Sechura desert of Peru, and they should be sought elsewhere, particularly in Baja California, and along the west coast of Africa. The organic-rich muds that should be associated with some phosphate deposits on the present sea bottom have been little explored thus far, but from knowledge of fossil deposits some of them may be presumed to be rich in hydrocarbons (Brongersma-Sanders, 1948), sulfur, and minor metals. Even though there may be no present commercial interest in hydrocarbons in muds on the present sea bottom, the upwelling province generally has excellent prospects for oil and gas, both on the continental shelf and the adjacent coastal plain. By no means is all petroleum derived from source beds deposited in the upwelling envirornment; in fact, the petroleum in most fields probably has no genetic relation to upwelling. Nevertheless, the rate of production of organic matter in the upwelling environment is much greater than that in other environments (Ryther, 1963; Wooster and Reid, 1963), and the petroleum fields that appear to be genetically related to such source beds (some of those of California and Venezuela, for example) are extremely rich. The areas of upwelling shown on fig. 2, particularly those of divergent upwelling, are therefore favorable provinces for offshore petroleum exploration. Another submarine terrane, not necessarily related to upwelling, that deserves consideration for its petroleum potential is that beneath the deep ocean floor and continental slope (Hess, 1962, McKelvey, 1966). Thus far these environments have barely been mentioned as possible petroleum-bearing provinces, but the success of the Mohole drilling indicates that they may soon become accessible to the drill. The question is, then, do they contain petroleum? It is easy to think of reasons why they do not contain signifi- cant amounts--the thin sedimentary section, high chance of destruction of organic matter prior to burial, probable lack of warping or folding over many areas and consequent lack of drive for migration and of traps for accumulation. But the ocean floor is complex geologically. We may assume that much, perhaps even most, of it does not contain recoverable petroleum, just as most of the land area does not, but this could leave a still enormous province. Consider, for example, the nutrient-rich waters along the equatorial currents and those in polar regions that are so productive of organisms. Consider the possible local accumulation of moderately thick sediments generated within the ocean by volcanic, chemical, or bio- chemical processes, or brought to it by turbidity currents. And consider evidence for diastrophic movements of the ocean floor, suggested by its topography and by geophysical observations. Areal coincidence or concatenation of these phenomena might well lead to the accumulation of petroleum. And with the possible lateral shift of ocean currents over geologic time with polar migration and continental and island development, favorable environments might be widely distributed. Oil seeps are known in the Gulf of Mexico beyond the limits of the contin- ental shelves (Pepper, 1958), and numerous structures suggestive of salt domes have been identified there in the Sigsbee Deep and on the upper continental slope (Ewing, Worzel, and Ewing, 1962; Ewing and Antoine, 1966; Murray, 1966). The Mozambique Channel between Madagascar and the African continent is believed by Pepper and Everhart (1963) to be under- lain by a large synclinorium, and seismic profiling has identified many areas in all the oceans in which there appear to be sediments 4 to 5 km in thickness (Ewing and Tirey, 1961). It is not possible yet to say that these or other structures contain recoverable petroleum, and it may be some time before petroleum exploration on the deep ocean floor is practical. But in view of the magnitude of future needs for petroleum, the possibility that 52 recoverable petroleum occurs beneath the ocean floor surely deserves serious study. RESIDUAL DEPOSITS OF TERRIGENOUS ORIGIN Residual deposits of terrigenous origin include sand, gravel, gold, platinum, diamond, monazite, cassiterite, magnetite, ilmenite, rutile, scheelite, chromite, and other resistates; and aluminum-rich clays and other hydrolyzates. Of these, it is the heavy mineral placers that are of chief current interest, and that will be the principal subject of the discussion here. Placers in the marine environment are mainly confined to the inner edge of the continental shelves in beaches, raised beaches, submerged beaches, offshore bars, and buried river channels. In some areas, however, there are offshore deposits related to bottom topography and offshore currents rather than to beach or alluvial processes (Griggs, 1945). The geographic distribution of placers is controlled by a number of variables that may be essentially independent of one another, including: petrography of the source terrane, climatic and tectonic history in both source terrane and depositional environment, present and ancestral drain- age pattern, and present oceanic circulation. In attempting to define areas favorable for submarine placers, one of the simplest and surest approaches is to begin with the known beach placers (see Hess, 1965, for a good summary). Figure 5 shows those that are past or present producers, and most of these localities would be prime targets for exploration off- shore. It was this type of clue, for example, that led to the recent discovery of diamonds off the coast of Southwest Africa (Bascom, 1964) and that has stimulated exploration for gold off the coast of Alaska. One promising lead of this type has been identified by W. C. Overstreet (Olson and Overstreet, 1964, p. 30), who points out that "the interesting pos- sibility, apparently as yet unexplored, exists that in the Gulf of Mannar area, shallow-water deposits along Adams Bridge between India and Ceylon may contain monazite. Beach placers are present on opposite shores of the Gulf. Currents setting northeastward through the Gulf may effect along-shore transport of monazite and concentrate it, as a great natural riffle, on the beaches near and in the shallow water of the Adams Bridge area." Also of much interest to the prospector are occurrences of beach placers not yet under production (fig. 5); there are many of these, and some may well provide clues to workable offshore deposits. Drowned channels of rivers that contain placers upstream, or of rivers that cross terranes known to have lode deposits may also be considered favor- able areas. The offshore tin deposits of Billiton, Indonesia (Van Over- eem, 1960), and some of those of Thailand are drowned alluvial deposits discovered from this kind of evidence. Beyond these clues provided by known mineral deposits, there are some general principles that may help define broad areas promising for marine placers. Nearly all valuable placer minerals are formed by igneous, hydrothermal, or metamorphic processes, so of course the regional proximity of source terranes that contain intrusive igneous and metamorphic rocks is a generally favorable feature, even though many individual placers are formed by the reworking of older marine or alluvial deposits. The presence of older coastal plain sediments seaward from the source terrane is also a favorable feature, for such deposits often form a protore from which the present beach sands are concentrated (W. C. Overstreet, unpub. data). For example, belts of monazite-bearing sediments back up the beach placers in India, southeastern United States, and Brazil, and older sediments are in part the source of the chromite beach placers of Oregon (Griggs, 1945) and the ilmenite placers along the southern coast of Queensland, Australia (Gardner, 1955). 53 130 ISO 140 Ito 00 8o 00 40 00 0 00 40 60 so 100 100 140 16O 180 401~~~~~~~~~~~~~~~~~~~~~I3 00 60 ~~~~~~~~~~~~~~~~~~~~Post or preetpoue Prospect, .knownpouto Arrow poiots to offshore producer or prospect ISO 560 140 100 too 80 60 40 00 0 20 40 60 00 100 020 140 160 00o Figure 5. World distribution of coastal placer dePOSits Equally important is the climatic history of the source terrane. Deep chemical weathering sets the stage for placer development by decomposing many of the silicate minerals of the host rock and increasing the ratio of the heavy, valuable mineral grains to the light, nonvaluable ones. It is significant that many of the world's great placer districts--India, Ceylon, Thailand, Indonesia, and Brazil, for example--are in areas of tropical or subtropical climate (W. C. Overstreet, unpub. data); other placers, such as those in California, were derived during periods of deep weathering in the Tertiary (Chaney, 1932; Jenkins, 1935). In a totally different climate, rapid physical disintegration of host rocks accomplished through frost weathering is also effective in liberating heavy minerals from source terrane. According to David Hopkins (oral communication, 1966), frost weathering is a key agent in the formation of Alaskan placers. Glaciation, however, particularly continental placiation, generally makes a negative rather than positive contribution to placer formation, for it mixes and hence dilutes rich source materials with the lean on a vast scale. Workable placers, therefore, are rarely derived from drift and are uncommon in glacial outwash (Jenkins, 1935). Aside from submerged residual and alluvial placers, the marine placers are concentrated by waves and currents, and it has long been observed (Raeburn and Milner, 1927, p. 48) that big seas and a persistent wind direction are favorable for the development of placers on modern beaches. Strong along- shore currents also may lead to the development of placers, perhaps a long distance from the source terrane. Grain size is commonly reduced during such transport, and there is some tendency for enrichment in rutile and zircon in the heavy-mineral assemblage as weak minerals (e.g., gold, magnetite, and monazite) are destroyed by abrasion, solution, or attrition. The efficiency of the bedrock or substrate in trapping heavy minerals is also an important factor in the localization of placer deposits (McKinstry, 1948, p. 227) and may be an element worthy of scrutiny in prospecting, particularly in searching for minable deposits within favorable areas. Rocks whose surfaces tend to be pitted or cracked are more effective traps than those with smooth or homogeneous surfaces. Tectonism may also influence the formation of marine placers. In the fossil record, the most pronounced basal conglomerates are associated with transgression, and in modern placers in areas where there are several shorelines, the richest deposits are generally associated with the highest beach. Shorelines of submergence, particularly where open, heavy seas are transgressing deeply weathered favorable source terrane, are good areas for prospecting, whether or not beach placers are already known to occur in the area. Aluminum-rich clay and bauxite in the marine environment are not of much interest now, but they may have some potential. Along with the heavy residual minerals, they are best developed in areas of deep weathering. Known deposits over the world are mainly in areas of tropical and sub- tropical weathering, and Goldberg (1964)has shown that even in the deep sea, sediments at low latitudes are enriched in hydrolyzate minerals. It goes without saying that residual clays and hydraulic placers are locally antithetic, even though both may be found within the same climatic environment. Residual clays may be preserved on the bottom in trans- gressing seas where wave and current action is not intense, and transported clays may be looked for in deeper, quieter water than is favorable for the concentration of placers. HOT-SPRINGS MANGANESE DEPOSITS Interest in manganese in the marine environment has focused largely on the manganese oxide nodules, which are extremely widespread in both deep (ero, 1965) and shallow (Manheim, 1965) water. Extensive though these deposits may be, they are comparatively low grade and pose difficult recovery problems. There is a potential in marine sediments, however, for 55 a different kind of deposit; the thick, high-grade deposits of manganese oxides or carbonates associated with submarine hot springs or volcanic exhalations. D. F. Hewett (1966) has described these deposits rather fully from the fossil record, and has presented ample evidence for their hot-spring origin. Iron and manganese precipitates have recently been identified from the submarine Banu Wuhu volcano, Indonesia (Zelenov, 1964), and hot brines from which iron oxides, manganese oxide and carbonate, and other metals are precipitating have been found in deeps of the Red Sea (Miller et al, 1965). Manganese-rich nodules of this apparent origin have also been found off the southeastern coast of Japan (Niino, 1959). Judging from the fossil record, some strata-bound iron sulfide (Kinkel, 1966), iron oxide, and cinnabar deposits may also be of hot-spring origin, and other metals are not uncommonly present with the manganese oxides. The origin of the deep sea manganese nodules has been controversial, but is not at issue here. Regardless of how the scattered and widely dis- tributed nodules may form, there is no doubt that some manganese deposits do form in the submarine environment from hydrothermal solutions related to centers of volcanism. From the evidence of the fossil deposits, some of these should be of high quality, range from a few to scores of feet in thickness, and should be composed of either manganese oxide or manganese carbonate, often in a nonnodular texture (Hewett, 1966). Unlike many of the nodule occurrences, which are scattered over wide areas and accumulate very slowly, the stratified deposits are lens shaped and are confined to areas a few or a few tens of square miles or less in size, and they apparently accumulate relatively rapidly. High-grade deposits of this type probably contain only a fraction of the total manganese and other metals in the deep-sea nodules, but many could be mined now if found, and they constitute a practical target for current exploration. Areas of active or recently active volcanism are the prime regional targets for such deposits, and within them points or trends (in shallow water perhaps identifiable as thermal anomalies by aerial infrared surveying) of hot- spring discharge may be clues to the location of specific deposits. CONCLUSION The sea bottom represents an enormous future source of minerals, for even if only a fraction of it is underlain by usable deposits its great size insures a tremendous potential. Even though the marine minerals industry already has an annual production worth nearly $4 billion, it is still in its infancy, and the potential of the marine environment is largely unexplored. The success already achieved in submarine exploration for oil and gas, sulfur, tin, and diamonds demonstrates the utility of available field procedures and instruments in prospecting and clearly shows that the incentive of a profitable target can be matched by the capability for finding it. Full use of available data and principles to select the most favorable areas for prospecting should both improve its effectiveness and reduce its cost. In seeking to narrow the prospecting target, it is perhaps worth empha- sizing that it is the continental shelves and the shallower parts of the sea that are not only most accessible to exploration and mining, but that contain most of the presently valuable deposits. For the more distant future, the entire ocean floor is fair game, and if parts of it should prove to contain petroleum and if means are found to prospect and mine hypogene minerals such as may exist in some of the submarine ridges, the deep ocean may yield a variety of important minerals. It appears, however, that large areas of the sea floor are likely to contain not much more than a very narrow spectrum of low-grade and low-value deposits--nothing to compare in variety or richness of concentration with many minerals in the 56 shelf environment. For the immediate future, then, activities directed toward subsea mineral prospecting and development should focus on the shelves. Within highly favorable areas, reconnaissance prospecting can be highly effective, and it need not await the availability of geologic maps and related data. Prospecting on the sea bottom, as on land, will be most effective, however, when it can be carried out in the light of good understanding or areal geology. Recognizing the shelf as the broadly favorable area of the marine environment, it would, accordingly, be highly desirable to extend systematic geologic mapping and related geophysical surveys at scales of 1:1,000,000 and larger over the continental shelves. REFERENCES Bascom, W., 1964, Exploring the Diamond Coast: Geotimes, v. 9, no. 2, p. 9-12. Brongersma-Sanders, M., 1948, The importance of upwelling water to vertebrate paleontology and oil geology: K. Nederlandsche Akad. Wetensch. Afd. Natuurk., Tweede Sect., deel XLV, no. 4, 112 p. 1957, Mass mortality in the sea, in Treatise on marine ecology and paleoecology, v. 1, Ecology: Geol. Soec. America Mem. 67, p. 941-1010. Byrne, John V., 1964, The oceans: a neglected mining frontier: Oregon Dept. of Geology and Mineral Industries, The Ore Bin, v. 26, p. 57-69. Chaney, R. W., 1932, Notes on the occurrence and age of fossil plants found in the auriferous gravels of Sierra Nevada: Mining in Cali- fornia, v. 28, nos. 3/4, p. 299-302. Cheney, T. M., and Sheldon, R. P., 1959, Permian stratigraphy and oil potential, Wyoming and Utah: Intermountain Assoc. Petroleum Geol. Guidebook Tenth Ann. Field Conf., p. 90-100. Dietz, R. S., Emery, K. O., and Shepard, F. P., 1942, Phosphorite deposits on the sea floor off southern California: Geol. Soec. America Bull., v. 53, p. 815-848. Ewing, J. I., and Tirey, G. B., 1961, Seismic profiler: Jour. Geophys. Research, v. 66, no. 9, p. 2917-2927. Ewing, J., Worzel, J. L., and Ewing, M., 1962, Sediments and oceanic structural history of the Gulf of Mexico: Jour. Geophys. Research, v. 67, p. 2509-2527. Ewing, M., and Antoine, J., 1966, New seismic data concerning sediments and diapiric structures in Sigsbee Deep and upper continental slope, Gulf of Mexico: Am. Assoc. Petroleum Geologists Bull., v. 50, p. 479-504. Fleming, R. H., 1957, General features of the oceans, in Treatise on marine ecology and paleoecology, v. 1, Ecology: Geol. Soc. America Mem. 67, p. 87-108. Gaber, N. J., and Reynolds, D. F., Jr., 1965, Ocean engineering and oceano- graphy....from the businessman's viewpoint: Ocean Sci. and Ocean Eng., Marine Tech. Soec. and Amer. Soec. Limnology and Oceanography, Trans. Joint Conf., June, 1965, p. 128-148. 57 Gardner, D. E., 1955, Beach-sand heavy-mineral deposits of eastern Australia: Australia Bur. Mineral Resources, Geology, and Geophysics, Bull. 28, 103 p. Goldberg, E. D., 1964, The oceans as a geological system: New York Acad. Sci. Trans. ser II, v. 27, p. 7-19. Griggs, A. B., 1945, Chromite-bearing sands of the southern part of the coast of Oregon: U. S. Geol. Survey Bull. 945-E, p. 113-150. Hess, H. D., 1965, The ocean: mining's newest frontier: Eng. and Mining Jour., v. 166, Aug., p. 91. Hess, H. H., 1962, Geotimes, v. 6, no. 5, p. 23. Hewett, D. F., 1966, Stratified deposits of the oxides and carbonates of manganese: Econ. Geology, in press. Jenkins, O. P., 1935, New techniques applicable to the study of placers: California Jour. Mines and Geology, v. 31, no. 2, p. 143-210; reprinted as California Div. Mines Bull. 135, p. 149-216, 1946. Kazakov, A. V., 1937, The phosphorite facies and the genesis of phos- phorites: Sci. Inst. Fertilizers and Insecto-Fungicides, Trans. no. 142 (published for the 17th Internat. Geol. Cong.), Leningrad, p. 95-113. Kinkel, A. R., Jr., 1966, Massive pyritic deposits related to volcanism, and possible methods of emplacement: Econ. Geology, in press. Manheim, F. T., 1965, Manganese-iron accumulations in the shallow marine environment: Univ. of Rhode Island Narragansett Marine Laboratory, Occasional Pub. 3-1965. McCulloh, Thane, 1966, Gravimetric effects of petroleum accumulations-- a preliminary summary: U. S. Geol. Survey Circ. 530. McKelvey, V. E., 1959, Relation of upwelling marine waters to phosphorite and oil (abs.): Geol. Soc. America Bull., v. 70, p. 1783. 1963, Successful new techniques in prospecting for phosphate deposits: U. S. Papers for UN Conf. on Application of Sci. and Tech. for the Benefit of the Less Developed Areas, v. 2, Natural Resources, Minerals and Mining, Mapping and Geodetic Control, Washington, U. S. Gov't Print. Office, p. 163-172. 1966, Changes in patterns of energy consumption and their bearing on exploration: Indian Minerals, in press. McKelvey, V. E., Swanson, R. W., and Sheldon, R. P., 1953, The Permian phosphate deposits of western United States: Internat. Geol. Cong. 19th, Algiers, 1952, Comptes Rendus, sec. XI, p. 45-64. McKelvey, V. E., Williams, J., Sheldon, R. P., Cressman, E. R., Cheney, T. M., and Swanson, R. W., 1959, The Phosphoria, Park City, and Shedhorn formations in the western phosphate field: U. S. Gaol. Survey Prof. Paper 313-A, p. 1-47. McKinstry, H. E., 1948, Mining geology: Prentice-Hall, New York, 680 p. eMaro, John L., 1965, The mineral resources of the sea: Elsevier, New York, 312 p. 58 Miller, A. R., Densmore, C. D., Degens, E. T., Hathaway, J. C., Manheim, F. T., McFarlin, P. F., Pocklington, R., and Jokela, A., 1965, Hot brines and recent iron deposits in deeps of the Red Sea: U. S. Geol. Survey, open-file report; Geochimica et Cosmochimica Acta., in press. Murray, G. E., 1966, Salt structures of Gulf of Mexico basin--a review: Am. Assoc. Petroleum Geologists Bull., v. 50, p. 439-478. Murray, J., and Renard, A., 1891, Report on deep-sea deposits, in Report on the Scientific Results of the voyage of H.M.S. "Challenger": Eyre and Spottiswoode, London, v. 5, p. 1-525. Niino, H., 1959, Manganese nodules from shallow water off Japan: in Sears, M., (editor), Internat. Oceanog. Cong. Preprints, Am. Assoc. Adv. Sci., p. 646. Olson, J. C., and Overstreet, W. C., 1964, Geologic distribution of resources of thorium: U. S. Geol. Survey Bull. 1204, 61 p. Pepper, J. F., 1958, Potential mineral resources of the continental shelves of the Western Hemisphere: U. S. Geol. Survey Bull. 1067, p. 43-66. Pepper, J. F., and Everhart, G. M., 1963, The Indian Ocean, the geology of its bordering lands and the configuration of its floor: U. S. Geol. Survey, Misc. Geol. Inv. Map 1-380. Pevear, D. R., 1966, The estuarine formation of United States Atlantic coastal plain phosphorite: Econ. Geology, v. 61, p. 251-256. Raeburn, C., and Milner, H. B., 1927, Alluvial prospecting: Thomas Murby, London, 478 p. Ryther, J. H., 1963, Geographic variations in productivity: In Hill, M. N., (editor), The sea, v. 2. Interscience, New York, p. 347-380. Sheldon, R. P., 1964a, Paleolatitudinal and paleogeographic distribution of phosphorite: U. S. Geol. Survey Prof. Paper 501-C, p. C106-0113. 1964b, Exploration for phosphorite in Turkey--a case history: Econ. Geology, v. 59, p. 1159-1175. 196_, Long-distance migration of oil in Wyoming: ECAFE, Third symposium on the development of petroleum resources of Asia and the Far East, Tokyo, Japan, Proc., in press. Smith, P. V., 1954, Studies on origin of petroleum--occurrence of hydro- carbons in recent sediments: Am. Assoc. Petroleum Geologists Bull. v. 38, p. 377-404. Sverdrup, H. U., Johnson, M. W., and Fleming, R. H., 1946, The oceans: Prentice-Hall, New York, 1086 p. Van Overeem, A. J. A., 1960, The geology of the cassiterite placers of Billiton, Indonesia: Geologie en Mijnbouw, v. 39, p. 444-457. Wooster, W. S., and Reid, J. L., 1963, Eastern boundary currents: In Hill, M. N., (editor), The sea, v. 2. Interscience, New York, p. 347-380. Wyatt, M., 1956, Phosphate deposits in Baja California, Mexico: Int. Geol. Cong., 20th, Mexico City, 1956, Resumenes de los trabajos presentados, p. 108. 59 Zelenov, KC. KC., 1964, Iron and manganese in exhalations of the submarine Dana Wuhu volcano (Indonesia): Akad. Nauk SSSR, Dokiady, p. 155, p. 1317-1320 (AGI transi.). 3, 5,-t. n- ~ ~ ~ ~ ~ tt- - ~~~60 . -J- REVIEW OF MINERAL VALUES ON AND UNDER THE OCEAN FLOOR John L. Mero, Ocean Resources, Inc. ABSTRACT For consideration of mineral deposits, the ocean can be divided into several regions, the beaches, seawater, the continental shelf, the deep-sea floor, and the rocks underlying the ocean floor. In the offshore beaches are found placer deposits of gold, platinum, diamonds, magnetite, ilmenite, zircon, rutile, cassiterite, scheelite, calcium carbonate, sand and gravels, and columbite. Reserves of economic mineral deposits in the offshore beaches have never been defined adequately, but are estimated to be several times that of the known on- shore beaches. From seawater is obtained bromine, mag- nesium, common salt, potash, magnesium compounds, soda gypsum, uranium and fresh water. Seawater is also a potential economic source of sulphur, borax and fluorine using present technological methods of extraction. A recently developed technique may make seawater a poten- tial source of many minerals. Reserves of any material taken from seawater are essentially unlimited. The con- tinental shelves hold deposits of calcareous shells, phosphorite, glauconite, barium sulphate nodules, and placer deposits of heavy minerals in submerged river chan- nels. The economic phosphate reserves of te shelf are estimated to be in excess of 200 billion tons. The sub- sea floor rocks contain deposits of oil, gas, sulphur, salt, coal, iron ore, and, possibly, other mineral de- posits in veins as on land. On the deep-sea floor are found essentially unlimited deposits of manganese, nic- kel, cobalt, copper, iron, molybdenum, vanadium, diato- maceous earth, limestone, and other metals. In most cases, deposits of the minerals found in the deep sea are forming at rates greatly in excess of present day world consumption of these materials. Introduction While the ocean contains innumerable mineral deposits, only a fraction of these deposits can be considered economically exploitable at the present time. Neverthe- less, those deposits which are economically exploitable are of sufficient volume to provide the world with its total consumption of many industrially important minerals for thousands of years at present rates of consumption. Given this knowledge, why is it that the minerals in- dustry is moving so cautiously into the offshore? It is not because the deposits of solid minerals are not in the offshore area for they definitely are. And, in many cases they are very high-grade deposits. It is also not because these offshore mineral deposits are difficult to find, for sea-floor accumulations of gold, diamonds, platinum, tin, manganese, nickel, cobalt, copper, phosphorite, and so on are among the least difficult of mineral deposits on earth to discover and explore. The bulk of these deposits are 61 either lying directly offshore of deposits exploited from the adjacent onshore area or they are lying exposed at the surface of the sea floor. It is also not because these deposits are difficult to exploit for gravels, sands, and nodules lying exposed at the surface of the offshore sed- iments are among the least difficult of materials on earth to mine. When considering, however, that almost 60 years elapsed between the time offshore oil deposits were discovered and the time they were being exploited on a large scale, it may be premature to assume that the mining industry is moving too slowly into the offshore area. For many of the sea floor mineral deposits have only comparatively recent- ly been recognized for their economic value. Then too, while the offshore oil deposits are substantially no different in their geologic character than those onshore, many of the offshore solid mineral deposits are. Ocean miners, consequently, are faced with a doubly difficult task of dealing, not only with a new environment in which to work, but a new type of deposit as well. Thus, the major reasons for the default of the mining industry in moving aggressively into the offshore can apparently be summed up as due to a lack of dissemination of adequate information as to the nature of the mineral deposits of the sea and due to underdeveloped technologies for ex- tracting many of the minerals found therein. We must also include in this default the extreme caution of the min- erals industry throughout the world in approaching new ,technologies. It is, however, a caution bred from the hazards of working with an environment that is difficult to understand, capricious in its reaction to men's efforts to subdue it, and only grudgingly yielding of its riches. THE DEPOSITS OF THE SEA Annually, the rivers of the world dump hundreds of mil- lions of tons of material into the sea. Most of the elastic sediments rapidly settle to the seafloor in near shore areas. The dissolved load of the rivers, however, mixes with seawater and is gradually dispersed over the total oceanic envelop of the earth. While the kinetics of chemical reactions in the sea is generally almost im- measurably slow, because of its immense size, the ocean is acting on a significant scale to separate, recombine, and eventually concentrate on the seafloor many of those minerals which are found to be necessary in an industrial society. As a result of this concentrating process, the ocean floor holds many mineral deposits which, if found on the continents, would be considered high-grade ores. Because of the nature of the minerals contained therein, it is convenient to consider the deposits of the sea as occurring in several environments: 1) marine beaches; 2) seawater; 3) continental shelves; 4) subsea-floor consolidated rocks; and, 5) the deep-sea floor. Miner- als are presently mined from all of these regions save for the deep-sea floor which has only recently been recognized 62 as a repository for mineral deposits of unbelievable ex- tent and truly significant economic value. The types of minerals found in the offshore areas are indicated in Table I. Marine Beach Deposits Because of the crushing, grinding, and concentrating action of the ocean surf, much of the processing of miner- als in the beaches has been done by nature. What mining and processing is left to do is, in general, uncomplicated and inexpensive. Beach deposits of unusually low-grade, thus, are often economic to exploit. From marine beaches come diamonds, gold, magnetite, columbite, ilmenite, zircon, scheelite, monazite, platinum, and silica, to men- tion the most important commercial minerals. Beaches have been mined for many years in some areas of the world with periodic storms, in some cases, replenishing tne mined out areas such as in Ceylon where the same areas of the same beaches are mined on a seasonable basis. In general, ]however, present beach deposits tend to be of a limited extent. In the offshore areas, however, can generally be found a series of beaches which contain minerals of the same type as the onshore beaches. During the Ice Ages, sealevel was appreciably lowered as the ocean water was transferred to the continental glaciers. Because of the cyclic nature of the Ice Ages and the intervening warm periods, a series of beaches were formed in areas offshore present beach deposits. Thus, the offshore potential is generally much greater tnan the onshore for mineral pro- duction. With recently developed sonic devices, it is not difficult to locate and delineate these submerged beaches. At the present time, it is quite impossible to assess the total mineral content of the offshore beaches, however, it is safe to assume that this potential is at least five to ten times the onshore potential. An interesting facit of beach deposits it that they tend to contain mineral streaks that are abnormally rich. Along the south shore of the Seward Peninsula in Alaska, beach deposits have been located which contain as much as $250 worth of gold per cubic yard of gravel (Brooks, et al., 1901). While these paystreaks tend to be limited in size (normally yielding less than about $1 million in total values) they..are highly economic to exploit and, thus, most important as capital resource generators. Because of the large number of beaches to be found in the offshore area, it can be expected that the number of these high- grade paystreaks will also be large and that the total values contained therein will be substantially more than found in the present sea level beaches. While the tech- niques of finding and blocking out such deposits are rather sophisticated, it is only recently that industry has considered the problems involved in exploiting these offshore placer deposits. Offshore mining technology, however, is developing at an accelerating pace, and it can be expected that substantial advances will be made in this field in the next few years. 63 Table 1 Mineral Deposits of the Sea Region Minerals of Interest MARINE BEACHES Placer deposits of gold, platinum, diamonds, magnetite, ilmenite, zircon, rutile, columbite, chromite, cassiterite, scheelite, worlframite, monazite, quartz, calcium carbonate, sand and gravels. CONTINENTAL Calcareous shell deposits, phosphorite, glauconite, barium sulphate nodules, sand SHELVES and gravels, placer deposits in drowned river valleys of tin, platinum, gold, and other minerals. SUBSEA-FLOOR Oil, gas, sulphur, salt, coal, iron ore, and, possibly other mineral deposits in ROCKS veins and other forms as in the rocks on land. SEAWATER Common salt, magnesium metal, magnesium compounds, bromine, potash, soda, gypsum, and potentially, sulphur, strontium, borax. Most other elements can be found in seawater and given recently developed extraction techniques seawater is a potential source of uranium,..liolybdenum, etc. DEEP-SEA FLOOR Clays - for structural uses, possibly also for alumina, copper, cobalt, nickel and other metals. Calcareous Oozes - as cement rock and other calcium carbonate applications. Siliceous Oozes - as silica and in diatomaceous earth applications. Animal Remains - as a possible source of phosphates and metals such as tin, lead, silver, and nickel. Zeolites - as a source of potash. Manganese Nodules - as a source of manganese, iron, cobalt, nickel, copper, molybdenum, vanadium, and possibly many other metals. Seawater Seawater is generally considered to have dissolved in it all of the natural elements. Covering an area of about 140 million square miles at a mean depth of about 2.5 miles, the sea holds about 330 million cubic miles of water. Seawater contains an average of about 3.5 percent of elements in solution, thus, each cubic mile of seawater, weighing about 4.7 billion tons, holds about 166 million tons of solids. Nine of the most abundant elements con- stitute over 99 percent of the total dissolved solids in seawater. Only four of these elements are commercially extracted at the present time to a notable extent; sodium and chlorine in the form of common salt, magnesium and some of its compounds, and bromine. Several calcium and potassium compounds are produced as by-products in salt or magnesium extraction processes, and, with the continued interest in fertilizer production, the day is probably not far off when potash will be commercially extracted from the sea. The commercial extraction of any element or compound from the sea, of course, immediately makes reserves of that material unlimited, and such is the case for magnesium and bromine, the bulk of which are extracted from seawater for consumption in the United States. Bromine is almost purely a marine element; over 99 percent of the bromine in the earth's crust is in the ocean. There is about $0.02 worth of bromine per ton of seawater, thus, when being processed for this element, seawater is probably the lowest-grade ore known. More significant, the $0.02 per ton of contained element value is probably the lower limit of ore grade when considering seawater as a source of any element by using conventional extraction techniques, that is, by taking the water out of the ocean, pumping it through a plant, adding some reagent to the water, per- forming a chemical or physical separation technique, and exhausting the barren seawater in a manner so as not to contaminate the incoming seawater. Unconventional techniques have recently been developed, however, which may permit the recovery from seawater of many elements with a concentration much less than that of bromine. The National Physical Laboratory in Great Britain recently announced the development of a technique which permits the recovery of uranium from seawater at a cost competitive with that of winning uranium from low-grade continental ores. This technique utilizes an ion exchange resin which is highly selective for uranium ions in the presence of the vast excess of other ions present in sea- water, and tidal currents to flush the seawater through the resin beds. There is about $0.0001 worth of uranium per ton of seawater, however, considering the nature of this process, we cannot assume that this concentration is at all a lower limit to the value of an element that can be extracted from seawater using this technique. Table 2 lists several of the elements that may be extracted by this process. Extension of this technique to any other of 65 Table 2 Chemical Analyses of Sea-Floor Phosphorite Off California Element Southern California Northern California Florida Phosphate Offshore Area Offshore Area Rock, Typical P205 31.9 32.2 31.3 C02 4.8 4.8 3.67 Fe 1.9 0.88 1.0 Mg 0.56 0.44 0.22 SiO2 4.25 7.43 9.55 Al 3.46 1.74 0.67 F 3.51 3.34 3.70 C1 0.028 0.027 0.020 Ca 33.08 32.0 32.8 Na 1.41 1.45 0.16 K 0.36 0.26 0.13 Moisture 1.54* 1.26* - *Samples were crushed, pulverized and dried at 100�C to constant weight prior to analysis. the elements in seawater, of course, immediately makes reserves of that element, as far as world consumption is concerned, unlimited. It would be entirely practical to anchor porous bags of these resins in areas of the ocean of high current flow or in the outfall of the cooling systems of seaside power plants or possibly to tow such bags behind merchant ships. Imaginative engineering such as the British have brought to bear on this matter, thus, could turn seawater into a major source of almost all minerals necessary to industrial societies. Another concept which should be evaluated when consider- ing seawater as a source of minerals is that of orebodies within seawater itself. As concerns the major elements dissolved in seawater, seawater is fairly uniform in com- position. Where the trace elements are concerned, seawater is not of a uniform composition. Values of gold in sea- water as high as 60 mg per ton have been found. Such a concentration works out to be about $0.06 worth of gold per ton of seawater. Even using conventional extraction techniques, a body of seawater containing 60 mg of gold per ton could be considered a high-grade gold mine if that body of water were of sufficient size. Thus far, very little work has been done to assess the size of these "high-grade" bodies of water within the ocean. In his general reconnaissance of the ocean, Haber (1927) found that the average content of gold in seawater was only about 0.004 mg per ton, or about $4 x 10-0 worth of gold per ton. Recently a body of water was found in the Red Sea that contains from 1000 to 50,000 times as much of such elements as iron, copper, manganese, and lead as does normal seawater (Miller, et al., 1965). Given the evap- orating conditions of the desert along the Red Sea, this body of water can probably be considered a mine of these elements and possibly several others. There are other bodies of water notably the Mediterranean Sea, in which such "orebodies" can possibly be found. Thus, it is possible to consider the seawater in the same context as the land as far as mineral deposits are concerned, that is, that the sea is not uniform in its composition, any more than the solid crust of the earth is uniform in its com- position. Deposits, or bodies of water, of unusually high concentrations of elements exist in the sea as in ore de- posits on land. FRESH WATER Fresh water, although not normally considered a mineral, is, potentially, one of the most important materials that can be extracted from seawater. In a few areas of the world such as Curacao Island and Kuwait for economic rea- sons, and Guantanamo Bay for political reasons, fresh water for domestic and industrial purposes is extracted from sea- water. In the United States, a number of plants have been constructed and placed into operation to study the various methods of extracting fresh water from the ocean. In gen- 67 eral, the production cost of the most efficient of the processes capable of recovering fresh water on a large scale from seawater at present is several times the cost of obtaining it from the ground or water sheds. Proposed large-scale nuclear reactor plants, which would produce electrical energy in conjunction with fresh water, however, appear to have very favorable production costs, especially in water short areas such as Southern California. Removal of water, of course, leaves the seawater enriched in salts and frequently higher in temperature. In conjunction with a seawater conversion plant, therefore, it would probably be profitable to operate a minerals extraction facility. Preliminary calculations have indicated that the produc- tion cost of fresh water can be lowered several cents per thousand gallons by extracting minerals from the effluent of such plants. If operated on a scale necessary to water some of the world's great seaside deserts, however, the production of minerals from seawater conversion plant effluents would grossly exceed present world consumption of a number of minerals such as salt or mganesium, but would produce disposable quantities of potassium, sulphur, or boron minerals. Continental Shelves The continental shelves of the world cover an area of about 10 million square miles or about 20 percent of the above water continental area of the earth. As the rocks of the continental shelves are basically similar to those of the adjacent continental areas, it can be expected that the mineral producing potential of the shelf rocks should be similar to that of the onshore orcks. And, in the case of petroleum, at least in the Gulf of Mexico area and off California, such is proving to be the case. Because of their cover of water, however, the continental shelves hold other types of mineral deposits which are economic to exploit with present day methods. CALCAREOUS DEPOSITS Calcareous shells are mined from offshore deposits in a number of locations, notably in the Gulf of Mexico, in San Francisco Bay and off Iceland. Since 1940 over 60 million tons of shells have been recovered from the area off eastern Texas for use in various chemical processes. One notable use is in the manufacture of lime for use in the precipita- tion of magnesium from seawater at the Dow Chemical Company plant at Freeport, Texas. An interesting shell deposit is mined about five miles off the southwest coast of Iceland to provide the raw material for a local cement industry in that country. A shoal of rock lying west of the deposit is home to a large popula- tion of various kinds of shelled animals. The winter waves break the shells free, crushing and grinding them. Tidal currents sweep the particles into Faxa Bay. The influx of shell material far exceeds the rate of extraction; thus, this deposit is a replenishing mineral deposit as opposed to land mineral deposits which are generally considered as depleting resources when mined. This renewing feature is 68 a common, and highly significant, feature of mineral de- posits in the sea. Calcareous deposits are also mined off the coasts of Hawaii and the Bahama Islands. GLAUCONITE Glauconite is an interesting authigenic mineral found in considerable quantity in various offshore locations. Fre- quently, it is found in deposits relatively uncontaminated with other materials. Being fine-grained and having no overburden would allow mining costs of less than $1 per ton for this material. Containing from four to nine percent of K20, the sea floor glauconite might be a source of potassium for agricultural fertilizers considering that its occurrence off the coasts of a number of nations would appreciably lower transport costs in moving this material to market. Glauconite is also used as a soil conditioner, in which application, the sea floor material could be utilized without expensive upgrading processes. PLACER DEPOSITS ON THE SHELF In Malaysia, Thailand, and Indonesia, tin is mined from river placers onshore to the present sealevel. These de- posits in many cases extend into the offshore areas. About ten dredges are presently operating in the Southeast Asian offshore tin fields and several new dredges are under con- struction for future operations in this area. Such de- posits are beginning to show up with increasing frequency, mainly because of the use of new seismic prospecting methods which allow rapid delineation of these sea-floor features even though the valleys and adjacent ridges are now completely buried by sediments. Drowned river valleys may also hold substantial placer deposits of gold and platinum off Alaska and of diamonds off the mouth of the Orange River in South-West Africa. What is the estimate of the values in these offshore river channels? This value is almost impossible to ascertain given the present data, however, we can expect it to be at least equal to the onshore potential considering the enormous extent of the continental shelf in the areas where such offshore placers are being found. If sealevel were to be lowered about 300 feet, an area almost as large as above water Alaska would show up in the Bering Sea, and, in Southeast Asia, such a lowering of sealevel would un- cover a land area as large as Australia. SEA-FLOOR PHOSPHORITE Of some interest at present are the phosphorite deposits found on the shelves off the coasts of many nations of the world. Thus far, phosphorite deposits have been found off Peru, Chile, Mexico, the west and east coasts of the United States, off Argentina, South Africa, Japan, and on the submerged parts of several islands around the Indian Ocean. At least 50 percent of the continental shelf area of Australia is presently under concession for phosphorite exploration. Such deposits, if found in this area, would be extremely valuable because the soils in Australia are 69 phosphate-poor, forcing that country to import large quan- tities of this material Off California, the sea-floor phosphorite occurs as nodules which vary in shape from flat slabs, several feet across, to oolites. The nodules are commonly found on the sea floor as a monolayer at the surface of coarse-grained sed- iments. The composition of the phosphorite from the California offshore area is surprisingly uniform. As in- dicated in Table 3, these offshore phosphorite deposits contain economically attractive amounts of phosphorous. While it is estimated that there are about one billion tons of phosphorite in the California offshore area (Emery, 1960), probably not more than 100 million tons of this phosphorite would be economic to mine at the present time. Much of this offshore phosphorite is found in topographic environments from which it would be ex- tremely difficult to recover and much of the near shore phosphorite is intermixed with gangue materials from which it would be difficult to separate at a reasonable cost. Still, the 100 million tons which are probably economic to mine would constitute a 200 year reserve at the present rate of consumption in the state of California. World-wide tonnage estimates of offshore phosphorite would probably be at least 100 times the amount estimated to be in the Southern California offshore area. Just recently, a new type of sea-floor phosphorite de- posit has shown up off the west coast of Mexico. This fine-grained, unconsolidated deposit of marine apatite lies in about 70 meters of water. Its total extent has yet to be assessed, however, its known dimensions are at least 60 by 160 kilometers in lateral extent. Its depth has also yet to be determined, however, a seismic probe survey indicates a depth of this deposit of at least 20 meters. The grade of this deposit is not overly spectac- ular, averaging possibly about 15 percent apatite, however, one section of the deposit covering an area of about 20 by 30 kilometers assays as high as 40 percent apatite. The only overburden on this deposit is water and the technology of nrining it has been worked out in the shell mining operation off Iceland. The apatite grain size distribution is quite limited and, since most of the gangue materials are contained in a clay-sized fraction, phosphate material from this deposit should be quite easy to concentrate to an acceptable grade. Considering only the high-grade section of this deposit, there should be at least 200 billion tons of recoverable phosphate mat- erials which is about 4,000 years reserves at the present rate of world consumption of this very important mineral commodity. The very recent discovery of this deposit was almost totally accidental. No one was looking for it. How many other such deposits can be found on the continental shelves of the world? We really won't know until we start looking for them in earnest. 70 Table 3 Status of Economic Extraction Technologies for Various Minerals from Seawater Concentration Total Amount Value of Material Reserves of Material Status of Material in Seawater of Material in a Ton of at Present World Extraction (mg/l) in Seawater Average Seawater Consumption Rates Technology* (Tons) ($) (Millions of Years) NaCl 29,500 45.6 x 1015 0.31 +1000 E. Magnesium 1,350 2.1 x 1015 1.00 +1000 E. Sulphur 885 1.4 x 1015 0.03 200 E. KC1 760 1.2 x 1015 0.024 300 E. Bromine 65 100 x 102 0.02 1000 E. Borax 50 70 x 1012 0.003 700 N.E. MoO3 0.1 25 x 109 0.0003 1 P.I.E. U308 0.006 10 x 109 0.0001 0.5 E.I.E. Silver 0.0003 5 x 108 10 x 10-6 0.1 E.I.E. Gold 0.000004 6 x 106 4 x 10-6 - P.I.E. Tin 0.003 5 x 109 6 x 10-6 0.1 P.I.E. Nickel 0.002 3 x 109 4 x 10-6 0.01 P.I.E. Copper 0.003 5 x 109 6 x 10-6 0.001 P.I.E. Cobalt 0.0005 1 x 109 1 x 10-6 0.1 P.I.E. *E. = Economic with present extraction techniques. N.E. = Not economic with present conventional extraction techniques. P.I.E. = Possibly economic with ion exchange extraction techniques. E.I.E. = Economic at present with ion exchange extraction techniques. SAND AND GRAVEL Probably the most prosaic of mineral commodities is sand and gravel, however, from a tonnage standpoint, it is easily the most important mineral commodity mined in the world. All industrial societies need copious quantities of this material in the manufacture of concrete, for fill, and for a myriad of other uses. Until recently, such material was generally extracted from pits near the market. Zoning regulations, however, are making the opening of new pits near cities impractical. In many areas construction gravels are now costing the user as much as $6 per ton, about 75 percent of this charge being transport costs. Especially along seaboard areas is the shortage of con- struction gravels acute. The offshore areas, of course, are well supplied with sand and gravel deposits, and, in some areas, notably off England, exploitation of these deposits has been initiated. Off the northeast coast of New Jersey an extensive deposit of this material has recently been discovered (Schlee, 1964) which deposit could easily supply the New York area at very favorable rates. Because much of the world's population is concentrating in the seacoast areas, the offshore gravel deposits will become increasingly import- ant sources of this material. Estimates of offshore re- serves of gravels cannot be realistically made at this time, however, data are now being gathered which should shortly allow cursory estimates to be made for the United States east coast area and for the Southern California area. An important application for offshore sand and gravel is in the building or replenishing of beaches. Off Florida, sand is mined to replenish eroded beaches on Jupiter Island. In California authorities are finding it more economic to build addtional beach area for recrea- tional purposes rather tnan buy waterfront footages which may cost in excess of $1 million per acre. Subsea-Floor Consolidated Rocks In areas offshore England, Japan, Newfoundland, and Finland, coal and iron ore are mined from subsea-floor rocks. These deposits are generally exploited by sinking shafts in the onshore rocks and driving drifts out under the sea and into the orebodies. Offshore methods, however, are used to discover and delineate these orebodies. Sulphur deposits are also found in the offshore areas, notably in the caps of salt domes. One such deposit was located while drilling for oil about seven miles off Grand Isle, Louisiana. This deposit is now mined by the Frasch process from the largest steel island ever built by man in the sea. Much of the sulphur of the United States is pro- duced from salt domes in the onshore areas around the Gulf of Mexico. Indications are that the concentration of salt domes offshore in this area is about the same as that on- shore and it can beexpected that the proportion of those domes containing mineable deposits of sulphur is about the 72 same also. Just recently a group of about 10 companies bid an aggregate of over $33 million for leases on about 75,000 acres of potentially sulphur porducing ground about 60 miles off Galveston, Texas. One of the successful bid- ders on one tract in this area plans to start exploration drilling within the next few months. The rocks of the continental shelf are basically similar in their geologic character to the rocks of the adjacent land area and it can be expected that the mineral pro- ducing potential is the same also. While we can expect to find vein and bedded mineral deposits within the rocks of the continental shelf, unless they can be exploited by conventional methods via shafts and drifts, it is unlikely that these deposits can be economically exploited with our present level of offshore mining technology. The Deep-Sea Floor It is the pelagic areas of the ocean, however, where nature is working on a truly grand scale to separate and concen- trate many of the elements that enter seawater. The min- erals that are formed in the deep sea are frequently found in high concentrations as in these areas of the ocean there is relatively little clastic material deposited to dilute the chemical precipitates. Eventually, the common igneous rocks of the continents may serve as a source of the min- erals needed in any industrial society. The pelagic sedi- ments of the ocean, however, will probably be considered first for these sediments contain an average of about ten times the amount of the industrially important metals as do the igneous rocks of the continents. These ocean- floor sediments also possess other advantages when being considered as a material to mine, that of being politically free and royalty free materials, they are widely distri- buted near most markets and are available to all on an equal basis. In addition, they are fine-grained, uncon- solidated, and in a water atmosphere which makes the use of automated hydraulic systems for recovery practical. RED CLAY Red clay covers about 102 million square kilometers of the ocean floor. At an average depth of about 200 meters, there would be some 1016 tons of red clay on the ocean floors. At an average rate of formation of five milli- meters per 1,000 years, the annual rate of accumulation of the red clays is about 5 x 10 tons. Table 4 lists some statistics concerning the amount of and rate at which the elements are annually accumulating in these sediments. While, from a mineral resource standpoint, the composition of the red clays is not particularily exciting, this mat- erial may nave some value as a raw material to be used in the manufacture of products such as construction materials or it may, in the future, serve as a source of various metals. While the average assay for alumina is about 15 percent, individual samples of red clay have assayed in excess of 25 percent alumina. Copper contents as high as 0.20 percent have been found in some red clays. 73 Table 4 Statistics on Amount of and Rate of Accumulation of Various Elements in Red Clay* Rate of World Ratio Ratio Abundance Amount in Accumulation Rate of (Amount (Rate of Element in Red Clay Red Clay in Red Clay Consumption in Red Clay) Accumulation) (Weight (Trillions (Millions of (Millions of (Annual (Rate of Percent) of Tons) Tons/Year) Tons/Year) Consumgtion) Consumption) Al 9.2 920. 46. 4.72 200. 10 Mn 1.25 125. 6.3 6.7 19. 1 Ti 0.73 73. 3.7 1.3 56. 3 V 0.045 4.5 0.23 0.008 550. 28 Fe 6.5 650. 32.5 262.5 2.5 0.1 Co 0.016 1.6 0.08 0.015 110. 5 Ni 0.032 3.2 0.16 0.36 8.9 0.5 Cu 0.074 7.4 0.37 4.6 1.6 0.1 Zr 0.018 1.8 0.09 0.002 900. 45. Pb 0.015 1.5 0.08 2.4 0.6 0.03 Mo 0.0045 0.45 0.023 0.040 11. 0.6 *After Mero, 1965. Nickel, cobalt, vanadium, lead, zirconium and several of the rare earth elements show up in red clays in amounts of several hundredths of a percent. An interesting aspect of the red clays is that the valuable minerals are generally contained in grains with a size range of 0.5 to 1 milli- meter while the gangue materials are generally contained in clay-sized particles. Thus, a sizing process could easily produce a concentrate of the valuable metals from these ocean floor clays. CALCAREOUS OOZES Calcareous oozes cover some 128 million square kilometers of the ocean floor or about 36 percent of its total area. The average thickness of the calcareous ooze layers has been estimated to be about 400 meters. Thus, there should be at least 1016 tons of calcareous oozes in the ocean. These oozes are estimated to be forming at an average rate of about 1 centimeter per 1,000 years, thus, each year some 1.5 billion tons of calcareous ooze is added to the ocean floor. Limestone, for which these oozes could be substituted, is presently mined at an annual rate of about 0.4 billion tons worldwide. If only ten percent of the ocean-floor deposits proved mineable, the reserves would be about five million years at our present rate of consumption. More interesting is that the calcareous oozes are accumulating about four times as fast as the world is presently consuming limestone. SILICEOUS OOZES Siliceous oozes cover about 38 million square kilometers of the ocean floor. At an assumed thickness of about 200 meters, there should be some 1015 tons of these oozes on the ocean floor. Normally, these oozes could serve in most of the applications for which diatomaceous earth is used, that is for fire and sound insulation, in light- weight concretes, as filters, as soil conditioners and so forth. MANGANESE NODULES Probably the most interesting of the oceanic sediments, especially from an economic standpoint,are the manganese nodules. These small, black to brown, friable concretions were discovered to be widely distributed throughout the three major oceans of the world almost 100 years ago by the famous Challenger and Albatross expeditions. It is estimated that there are some 1.5 trillion tons of mangan- ese nodules on the Pacific Ocean floor alone and that they are forming in this ocean at an annual rate of about 10 million tons. Averaging about four centimeters in diameter and lying loose at the surface of the sea-floor sediments in concentrations as high as 100,000 tons per square mile, the manganese nodules, from all calculations thus far made, are indicated to be highly economic to mine at the present time. Grading as high as 2.5 percent copper, 2.0 percent nickel, 0.3 percent cobalt, and 36 percent manganese, all in the same deposit, or as high as 2.1 percent cobalt or 75 50 percent manganese in other individual deposits, the ocean-floor manganese nodules would be considered as high- grade ores if found on the continents. Another interest- ing aspect of these nodules is that, over large lateral distances, their composition varies markedly. Thus, the mine site can be shifted into those deposits with a mix of metals that is most amenable to market conditions. Flexibility such as this in choosing the grade of mater- ial to be mined is a great advantage and one which the mining industry does not normally have in land mines. Table 5 lists statistics concerning the amounts of various elements in the nodules and the land deposits. Even if only ten percent of the nodule deposits prove economic to mine, it can be seen that many elements are accumulat- ing in the manganese nodules now forming on the Pacific Ocean floor faster than they are presently being con- sumed, in fact, three times as fast in the case of man- ganese, twice as fast in the case of cobalt, as fast in the case of nickel and so on. As is the case with many mineral deposits of the sea, the manganese nodules would be a renewable resource. The fact that many deposits of the sea are renewable resources is, of course, of academic interest only, for the reserves of the minerals contained in presently mineable deposits are generally measured in terms of hundreds of thousands or millions of years. Although the sea can certainly be claimed as a potential source of many important industrial minerals, it is not now, nore will it ever be, the source of all the minerals needed in an industrial society. Transportation economics will probably always dictate that such minerals as common salt will be mined near the market. Within the next sev- eral decades, however, I feel that the ocean will be an economic source of important quantities of such materials as potash, nickel, copper, cobalt, manganese, gold, pla- tinum, limestone, silica, diamonds, rare earths, iron ore, titanium, sulphur, fluorine, molybdenum, zirconium, vana- dium, phosphates, lead, and uranium, in addition to the salt, magnesium, bromine, tin, oil, gas, iron ore, and limestone which are now extracted from the sea on an economic basis. Whether or not the sea becomes a great mineral storehouse for humanity, of course, will be entirely based on the effort we choose to put into it. In an entirely new enter- prise, vision and faith are factors, sometimes of more importance than even capital. But simply on an economic basis, the sea-floor deposits merit serious consideration of all groups in the mining industry concerned with provid- ing society with necessary mineral conmmnodities at the lowest price possible consonant with good business practices. 76 Table 5 Reserves of Metals in Manganese Nodules of the Pacific Ocean* Amodnt of Reserves in Approximate Ratio of Rate of U.S. Rate of Ratio of Element Nodules at World Land (Reserves Consumption Accumulation (Rate of Element in Consumption Reserves of in Nodules) of Element of Element Accumulation) Nodules Rate of 1964 Element (Reserves in 1964 in Nodules (Rate of U.S. on Land) Consumption) (Billions (Years) (Years) (Millions of (Millions of of Tons) Tons/Year) Tons/Year) Mg 25. 600,000 L*- 0.04 0.18 4.5 Al 43. 20,000 100 200 2.0 0.30 0.15 Ti 9.9 2,000,000 L - 0.30 0.069 0.23 V 0.8 400,000 L - 0.002 0.0056 2.8 Mn 358. 400,000 100 4,000 0.8 2.5 3.0 Fe 207. 2,000 500 4 100. 1.4 0.01 Co 5.2 200,000 40 5,000 0.008 0.036 4.5 Ni 14.7 150,000 100 1,500 0.11 0.102 1.0 Cu 7.9 6,000 40 150 1.2 0.055 0.05 Zn 0.7 1,000 100 10 0.9 0.0048 0.005 Ga 0.015 150,000 - - 0.0001 0.0001 1.0 Zr 0.93 100,000 100 1,000 0.0013 0.0065 5.0 Mo 0.77 30,000 500 60 0.025 0.0054 0.2 Ag 0.001 100 100 1 0.006 0.00003 0.005 Pb 1.3 1,000 40 50 1.0 0.009 0.009 *After Mero, 1965. **Present reserves so large as to be essentially unlimited at present rates of consumption. References 1) Brooks, A. H., Richardson, G. B., and Collier, A. J., 1901, Reconnaissances in the Cape Nome and Norton Bay Regions, Alaska, in 1900. Special Publication of the U. S. Geologic Survey. 2) Emery, K. O., 1960. The Sea Off Southern California. Wiley, New York, N. Y., 366 pp. 3) Haber, F., 1927. Das Gold im Meerwassers. Z. Angew. Chem., 40: 303-317. 4) Mero, J. L., 1965. The Mineral Resources of the Sea. American Elsevier Publishing Co., New York, N. Y. 320 pp. 5) Miller, A. R., Densmore, C. D., Degens, E. T., Hathaway, J. C., Manheim, F. T., McFarlin, P. F., Pocklington, R., and Jokela, A., 1965. Hot Brines and Recent Iron Deposits in Deeps of the Red Sea. Woods Hole Oceanographic Institution Publication No. 65-38, Woods Hole, Mass. 6) Schlee, J., 1964. New Jersey Offshore Gravel Deposit. Pit and Quarry, December, 1964. 78 REVIEW OF AVAILABLE HARDWARE NEEDED FOR UNDERSEA MINING C. G. Welling/M. J. Cruickshank Co-Authors ABSTRACT In any mining system, five basic steps are involved. These are: location of the deposits, evaluation of the ore-body, extraction of the ore, beneficiation, and transportation. Cur- rent available hardware is reviewed with emphasis on the evalua- tion and extraction phases. The review considers the types of deposits that will be mined under the sea. These fall under two basic categories: consolidated and unconsolidated deposits analogous to hard rock and alluvial deposits on land. This clas- sification is further subdivided into surficial deposits which are those exposed on the sea floor and in situ deposits which are contained in the sediment or rock beneath. Current undersea mining operations are limited to underground mines worked con- ventionally from land or island base, in situ solution mining from off-shore platforms and shallow alluvial deposits close to shore worked by dredging. In all cases, the hardware involved is adapted from mining and petroleum industry tools. As is normally the case, each ore deposit represents an unique situa- tion. Therefore, it is emphasized that no one method will ful- fill the systems requirements for all mining operations. Avail- able tools are many and varied and hardware requirements become well established as new deposits are sought and discovered. The ultimate success of future undersea mining operations depends strongly upon the selection or development of the optimum equip- ment and systems for the particular task. INTRODUCTION The prospects of finding and recovering minerals from the shelves, slopes and basins of the ocean have generated considerable in- terest. While it is still very early in the phase of this new activity, some good beginnings have been made. The activities vary from broad economic and technical studies to actual opera- tions at sea. At the present time, it would be hazardous to guess at what rate undersea mining will grow, or what size the industry will ultimately become. If one is to learn anything from history, it is that enough attention will be given this new activity in the forthcoming years to provide a reasonable and sound basis for satisfactory growth. A review of the offshore oil industry reveals some interesting guide lines that may provide assistance in projecting a reason- able growth structure. However, one must be careful in any analogy and recognize the similarities and differences. Hind- sight is a wonderful thing, and it is very easy to rationalize now, for instance, that the growth of the offshore oil industry was practically assured. Very few believed this fifteen to twenty years ago. However, it was the extension of the oil field into the shallow waters off the Coast of Louisiana that provided the path for growth. For years, the drilling companies had been operating in swamps, bayous and rivers of Louisiana. The land drill- ing rigs were adapted to barges, piers and platforms. Very little was new except some of the operating procedures. It wasn't until 79 the water depth increased beyond the practical limits of fixed platforms and barges that the jack-up and semi-submerged plat- forms came into existence. The offshore oil industry has demonstrated considerable ingenuity in adapting extensive land know-how and equipment to the ocean environment on the continen- tal shelf. We now are witnessing the beginnings of a look be- yond the continental shelf. Seismic profiles indicate the pos- sible existence of oil in many parts of the basin of the Gulf of Mexico. It may be a few years before it is technically feasible and economical to explore or produce from such deep fields, but their possible existence acts as a goal for continuously increas- ing the ability to operate in deeper water. One need not postulate that undersea mining will evolve in a pat- tern similar to the offshore oil industry. However, it may be worthwhile to review where conditions are similar and where they are different. The projected increasing demands for many minerals should pro- vide, as it did in petroleum, a necessary attention to the under- sea areas. The probable existence of minerals in commercial quantities in some areas in the shallow water of the coastal regions will provide an evolutionary path for development. The extension of ore deposits from land into the shallow waters as a counterpart of the oil fields of Louisiana exists in several areas of the world - the two most well known are the diamonds of South- west Africa and the tin of Southeast Asia. In the case of the tin dredging in Southeast Asia, the evolution of offshore waters is beginning to take place with the apparent adapting of land tech- niques. There was more of a step function or change in the dia- mond operations off Southwest Africa. Here the environment of rugged coast line and generally rough seas demanded a new approach to diamond mining. Certainly such ores as manganese nodules which are not known to exist in shallow waters, will require an essen- tially new mining system. In spite of this, the principles and techniques developed in offshore oil platforms andmodern dredges may provide some necessary elements of these new systems. It is worthwile to state a few of the important dissimilarities between the offshore oil industry and the potential undersea mining industry. The market, or total dollar volume of petroleum exceeds by an order of magnitude or more, most other minerals. This has a strong impact upon the amount of risk capital available for development. It also is reasonable to state that ore deposits, their composition and location have a variation considerably greater than petroleum. This is true at least in the effect these deposit characteristics have upon the methods of locating and mining them. Therefore, operating methods and equipment should vary considerably. In this review one must of necessity limit the categories of equipment for practical reasons. Boats and ships that may be converted for survey and mining are not reviewed, nor is the large variety of general oceanographic equipment. With this as a background, I believe a review of available hard- ware needed for undersea mining will provide the required founda- tion for projecting the probable development of future equipment. One can divide the essential operations of land and marine mining into five separate activities: (1) The location of the deposits; (2) The evaluation of the deposits; 80 &;' MINERAL DEPOSITS' OFFSORE CONSOLIDATED UNCONSOLIDATED SURFICIAL IN SITU SURFICGIAL IN SITU EXPOSED STRATIFIED MASSIVE,VEIN OR SHALLOW PLACERS, BURIED RIVER AND DEPOSITS (COAL, TABULAR DEPOSITS BEACH OR OFFSHORE BEACH PLACERS, IRONSTONE, LIMESTONE, SULFUR, COPPER, IRON,SANDS, SILICA DIAMONDS, PLATINUM, CORALS) IRON, COAL, TIN, SANDS, LIMESANDS GOLD, TIN AUTHIGENIC GOLD, ETC. AUTHIGENIC NODULAR COATINGS (MANGANESE, DEPOSITS (Mn.,Co., Ni, PHOSPHORITE) Cu) PHOSPHORITE DEEP OCEAN FLOOR DEPOSITS, RED CLAYS, OOZES, ETC. Figure 1 (3) The extraction of the ore; (4) The beneficiation, and (5) The transportation. THE LOCATION OF THE DEPOSITS Before proceeding, it might be desirable to review the environ- ment of the mineral deposits to be expected off shore. Figure 1 is a graphic illustration in which the deposits are subdivided into consolidated and unconsolidated, and further subdividedinto surficial and in situ classifications. Starting at the right hand side of the chart, in the shallow water the deposits which are believed to be the easiest to recover are the buried river and beach placers, including, diamonds, platinum, gold, and tin. These minerals are the heavy group and normally canbe found resting on bedrock or impermeable clay covered by sediment. The uncon- solidated surficial deposits include the shallow placers either on beach or off shore, including iron sands, silica sands or lime sands. A second grouping includes the authigenic nodular depos- its. The phosphorite nodules normally are found in the shallower water of the continental shelf and the manganese deposits normally in the deeper waters. A third grouping includes the deep ocean floor deposits of red clay and oozes. The consolidated in situ deposits are the massive, vein, or tabular deposits including sul- phur, copper, iron coal, tin, gold, etc. The consolidated sur- ficial deposits include exposed stratified deposits such as coal, ironstone, limestone, and corals, and authigenic coatings of manganese and phosphorite. At the present time information available on marine mineral deposits is largely limited to the unconsolidated surficial deposits. Because of this, the discus- sion will be limited to available equipment that can be used, either directly or without great modification, to the mining of these deposits. Probably the two most important factors of direct bearing upon hardware in marine mining are the depth of water at the mine site, and the sea state condition of the water surface. Dredging for many years has been accomplished in shallow protected water. This environment is quite different from the open seas and the importance of this difference on design and operation of reliable equipment cannot be too strongly emphasized. Therefore, two characteristics - stability and mobility, may at times be the dominent characteristics of an ocean mining system. Other factors of importance are subsurface waves and currents which have been discovered in recent years and about which little is known at the present time. The sea environment also creates a problem for accurate positioning and location, particularly when the opera- tions are out of sight of land. While there are many other dif- ferences between land mining and undersea mining, these are believed to be areas where the environment produces the greatest differential. The activities and hardware used in the location of the deposits can be divided into three different categories: ship operation, survey and sampling. Because of the extensive amount of oceanog- raphic, hydrographic and geological work that has been done at sea, especially since World War II, an extensive variety of hard- ware has been developed and is available for ocean mineral survey work. This applies specifically to seismic survey equipment, magnetometers, and gravity meters used extensively by the offshore oil exploration industry. In addition to this, there is a wide varietyof equipment such as sampling tools, underwater television, cameras, and standard oceanographic equipment applicable to sea floor studies. 82 Ship Operations One of the most important factors in the location of undersea minerals is accurate navigation. Ore bodies must be relocated after being found and must be accurately delineated and defined. The accuracy required depends upon the phase of operations. Initially, in general surveys, errors of a thousand feet or more may be tolerated. However, once an ore body is believed to exist in a given area, maximum errors of less than 100 feet are desirable. These maximum tolerated errors may be further reduced to a few feet in detailed ore body delineation and extraction. The positioning accuracy desired is dependent upon many factors, costs, operating procedures, characteristics of ore body, etc. The development of electronic navigation systems starting with World War IIprovides, in many cases, systems with the required accuracy (Table 1). There are basically two types as shown in Figure 2. Hyperbolic pattern systems with a master and two slave stations at surveyed sites on shore, require a receiver aboard the survey vessel. There are many types available, of which the best known are Loran and Decca. There is no limit on the number of units or ships that can use the system simultaneously. Accuracy depends upon type of system, the location of the ship in the pattern and the distance of the ship from the stations. The ranging systemuses a master station aboard ship with two slave stations at surveyed sights on shore. In general only one ship can use this system at any one time. There are a variety of types available for use with accuracies from 3000' down to approximately 3'. Loran, Lorac, and Decca are permanently installed in various locations throughout the world as shown in Figure 3. Small portable systems are avail- able for local use that provide high accuracy within 30 to 50 mile ranges. Positioning During coring and mining operations, the vessel must be held steady over a selected spot on the ocean floor. The two proce- dures that have been fairly well developed are the multiple anchoring system, and the dynamic positioning system. Illustrated in Figure 4 is a three point anchoring system of value for a coring vessel working close to the surf. A series of cores may be obtained along the line of operations by winch- ing in the forward anchors and releasing the stern anchor. Good positive control over the vessel can be obtained with this sys- tem. If conditions warrant, a four point anchoring system may be used. Increased holding power can be obtained by multiple anchoring at each point. Illustrated in Figure 5 is a dynamic positioning system. It is useful in deeper water where anchoring may not be practical or allows too much movement of the ship. The ship is kept in posi- tion by use of auxiliary outboard propeller drive units. These can be placed both fore and aft to provide excellent maneuver- ability. The sonar transponders are held submerged at a depth of minimum disturbance. Ranges are obtained from the ship to the transducers by use of sonar. The auxiliary power units are then controlled to keep the ranges at a constant value. This can be done manually or automatically by use of a computer. 83 *TABLE OF ELECTRONIC POSITIONING SYSTEMS Range Accuracy Signal Area Name Naut-Miles Feet Type System Users Coverage Manufacturer Long Range>500 Miles Loran A 8-1400 1000' Pulsed Hyperbolic Multi See Chart Various Loran E 1500 500' Pulsed Hyperbolic Multi See Chart Various OMEGA 6000 3000' Pulsed Hyperbolic Multi Experimental Omega CONSOL 700 36-144,000 C.W. Azimuthal Multi Not in ?U.K. general use DELRAC 3000 60,000 Pulsed Hyperbolic Multi Not in Decca U.K. general use TRANSIT Worldwide High C.W. Sattelite Multi Experimental A.P.L. (U.S.N) U.S. Intermediate Range 100-500 Miles Loran B 250 45-300 Pulsed Hyperbolic Multi See Chart Various Loran A 200 10-150 C.W. Hyperbolic Multi See Chart Seiscor Okla. Loran B 300 10-150 C.W. Hyperbolic Multi See Chart Seiscor Okla. Decca Navigator 250-500 1500-12000 C.W. Hyperbolic Multi See Chart Decca Navigator Co. Eng. Decca Survey 200 25-300 C.W. Hyperbolic Multi See Chart Decca Navigator Co. Eng. Low Ambiguity 150-400 25-250 C.W. Ranging 1 Local Decca Navigator Co. Eng. Decca Decca 2 Range 150- 12- C.W. Ranging 1 Local Decca Navigator Co. Eng. Table 1 "'TABLE OF ELECTRONIC POSITIONING SYISTEMS Accuracy Signal Area Name Naut-Miles Feet Type System Users coverage Manufacturer Decca Hi Fix 200 3- C.W. Hyper or I Local Decca Navigator Co. Eng. Range E.P.I. 0 01~O 95-1500 Pulsed Ranging I Local D.M. Raydist 1OO-250 l-l5O C.W. Range- 2 Local Hayetings Raydist Inc. Hyperbolic Va. RANA 841~-29 60-120 C.W. Range -France HIRAN ~ 55 2 (?) C.W.(?) Range I Local Raydist ()U.S. Shiort Range>lOO Miles cmoRadar 30 300 C.W. Range or I Local multi Azimuth P.R.S. 50 150 C.W. Ranging 1 Local Alpine Geophys. Co. Tax. R.O.F. 50 5OCO C.W. Azimuth Multi Local multi Hi Fix 30 12-100 C.W. Ranging I Local Decca Navigator Co. Eng. Skioran 30 30-50 Pulsed Ranging I Local Raydist (?) Hi Fix 40. 25-150 C.W. Hyperbolic Multi See Chart Dacca Navigator Co. Eng. Hydrodist 25 C.W. Ranging I Local Hastings Raydist (?) M.P.F.S. 30 < 5O C.W. Azimuthal Multi N. Canada Canada Raydist 7515-150 C.W. Composite 2 Local Haystins Raydist Va. Table I (Contd) *TABLE OF ELECTRONIC POSITIONING SYSTEMS Range Accuracy Signal Area Name Naut-Miles Feet Type System Users Coverage Manufacturer Auto Tape 60 3+ C.W. Ranging 1 Local Cubic Corp. U.3. Mini Fix 30 2.5-7 C.W. Ranging or 1 See Chart Decca Navigator Co. Eng. Hyperbolic Doppler Very C.W. Sonic 1 Local Raytheon Co. R.I. Navigator Accurate Ranging Deep Sub- 10 5 degrees Azimuth Local Oceanographic Eng. Co. mergence Calif. R.O.F. Electro Tape < 50 > 0.01 C.W.U.H.F. Ranging 1 Local Cubic Corp. U.S. *Based upon information published or made available by the manufacturer. Table 1 (Contd) *NAVIGATION & SHIP POSITIONING: DEPTH RECORDERS Depth No. of Subbottom Weight Manufacturer Name of System Ft Scales Accuracy Recorder Penetration lbs Alden Electronics & P.S.G.R. 18000 12 Yes Yes Impulse Recording 18000 12 Yes Yes Equip. Co. Inc. Mass. 18000 12 Yes Alpine Geophysical PESR (Precision 24000 6 .01% Freq. Yes Yes 125 Associates, Inc.N.J. Echo Sounder Recdr.) Shift Yes Apelco Calif. Depth Sounder/ 360 2 5% Yes No 8 Recorder 360 2 5% No No 8 Bludworth Marine Survey Depth 245 4 2% Yes No 31 Div. S.E.C. N.Y. Recorder 245 4 0.5% Yes No 39 Daystrom Inc. Depth Indicator 3000 3 1% No No Elec. Div. N.Y. System E.D.D. Corp. N.Y. Depth Recorder 24000 3 Yes - 370 Survey Depth Recdr. 920 4 0.5% Yes Electro Acoustic Echograph 1080-3960 8 Yes No 130-750 G.M.G.H. W. Ger. 420- Fischlupe 1800 2 Scope No 94-176 Miniscope 490 4 Scope No 30-45 Ocean Sonic, Inc. Precision Sonar 12000 7 Yes Yes Calif. Recorder Raytheon Co. Precision Fathom- 24000 3 0.04% Yes No 175 Electrographic Sys. eter Recorder Dept R.I. Depth Alarm 10-150 1 No No 22 Litton Industries, PDR (Precision 24000 3 Yes No 250 McKiernan Terry Depth Recorder) 36000 8 Yes Yes 250 Marine Div. N.J. *Based upon information published or made available by the manufacturer. Table 2 "BASIC OFFSHORE ELECTRONIC LOCATION SYSTEMSR HYPERBOLIC HYPERBOLIC PATTERNS. MASTER $ BOTH SLAVES AT FIXED POINTS ASHORE. STATION I eS 7 h - I / STATION 2 J STRECEIVER ~ MASTER STATION MASTER STATION �RANGING TWO-RANGE. MASTER STATION ABOARD SHIP, BOTH SLAVES AT FIXED POINTS ASHORE, ONE VESSEL ONLY CAN OPERATE IN THIS MANNER. STATION 1 STATION 2 Figure 2 WORLDWIDE ELECTRONIC NAVIGATION SYSTE~ Co~~~~~~~~~~EC CD~~~~~~~~~~~~~Fgr 3 POINT ANCHORING SYSTE. 'Re Figare~~~~~~~~~~~ 4. KDYNAMIC POSITIONI NG BYSM DR~~DILLSPIP Figure NA Survey The primary aids to exploration for mineral deposits at sea are depth recorders, bottom sampling devices, sub-bottom profilers, magnetometers, and sub-bottom sampling systems. Examples of available hardware are shown in Tables 2, 3, and 4. Their use is dependent upon the characteristics of the ore being sought. Depth Recorders For the initial topographic survey of the sea floor, and as an aid to navigation, in inshore waters, the depth recorder (Table 2) is indispensable. It is usually carried as standard ship's equipment, but the precision recorders having a high accuracy are most useful in survey work. In the same range of accuracy, the choice will depend greatly on the economics of the system. Bottom Sampling Devices Many hundreds of variations of these devices exist for sampling the sea bottom. The choice is dependent on the requirement of the survey, but for the qualitative sampling of mineral sands, a grab type sampler such as the Shipek, where spillage is held to a minimum, is considered to be better than most. Nodular deposits are best sampled by a towed dredge which may be con- structed for the particular job. Sub-Bottom Profilers In the search for marine placer deposits of heavy minerals, the sub-bottom profiler is probably the most useful of all the exploration aids. It is one of several systems utilizing the reflective characteristics of acoustic or shock waves. These systems (Table 3) with the exception of the Westinghouse bottom scanner, provide sub-bottom profiles of the sea floor to maximum depths of 25,000 feet. The continuous seismic profilers are a development of standard geophysical seismic systems for reflection surveys, used in the oil industry. The normal energy source is explosive, and penetration may be as much as several miles. More recently developed are the sub-bottom profilers, which use a variety of energy sources including electric sparks, com- pressed air, gas explosions, acoustic transducers and electro- mechanical (Boomer) transducers. The return signals as recorded, show a recognizable section of sub-bottom. Shallow layers of sediment, configurations in the bedrock, faults and other fea- tures are clearly displayed and require little interpretation. The maximum theoretical penetration is dependent on the time interval between pulses and the wave velocity in the sub-bottom. A pulse interval of 1/2 sec. and an average velocity of 8,000'/ sec. will allow a penetration of 2,000', the reflected wave being recorded before the next transmitted pulse. The actual penetra- tion achieved is dependent on the wave velocity, the pulse fre- quency and the pulse energy. The resolution of the recorded data is dependent on the pulse frequency and the recorder sweep rate. Band filters are commonly used to clarify the recorded signal. 92 *GEOPHYSICAL PROFILING: WAVE REFLECTION SYSTEMS Sediment Manufacturer Name of System Penetration Power Energy Source Alden Electronic & Impulse PGR (Precision graphic -<200 feet 20,000 Joules Spark Recording Equipt. Co. Mass. recorder & seismic Explosive profiler) Alpine Geophysical Assoc. Seismic Reflection Pro- 4-5 Km Explosive Inc. N.J. filer CSP (Continuous Strat- 2,000 feet Variable Spark ification profiler) Bolt Associates, Inc. S.B.P. PAR Pneumatic )>100 feet Variable Pneumatic Conn. Sound Source Chesapeake Inst. Corp. Towflex Towed Hydro- Recorder Explosive Ma. phone Array for Seismic Only Deep Profiling Edgerton, Germeshausen & Boomer 1000' > 500 Joules Electro-Mech. Grier Inc. Mass. Sparkaray > 400' 1,000 Joules Spark Seismic Sabbottom Shallow Variable Acoustic Transducer Profiler Geotechnical Corp. Tex. SUBot (Subbottom Pro- 5,000' 3,600-25,000 Spark filer) Joules SSP (Seismic Section > 5,000' > 100,000 Joules Explosive & Gas profiler) GASSP 10-15,000' High Gas Explosion Geophysical Service, Inc. Seismic Deep Various Various Teax. Huntec Ltd. Can. Hydrosonde MK 2A (sub- Shallow 140 Joules Spark bottom profiling) Westinghouse Underseas Div. Ocean Bottom Scanner Surface Low Acoustic Transducer Only Table 3 *GEOPHYSICAL PROFILING: WAVE REFLECTION SYSTEMS Sediment Manufacturer Name of System Penetration Power Energy Source Rayflex Exploration Co. Sonoprobe < 50' 3 KW Acoustic Transducer Tex. U.E.D. Earth Science Div. Ocean Bottom Seismic Recorder Explosive Recording System Only Deep *Based upon information published or made available by the manufacturer. Table 3 (Contd) Penetration and resolution are widely variable features on most models of wave velocity profiling systems. In general, high frequencies give high resolution with low penetration, while low frequencies give low resolution with high penetration. The general range of frequencies is at the low end of the scale and varies from 150 to 300 cps, and the general range of pulse energy is from 100 to 25,000 joules for non-explosive energy sources. The choice of system will depend very much on the requirements of the survey, but for the location of shallow placer deposits on the continental shelf the smaller low powered models such as the Rayflex Sonoprobe and the Huntec Hydrosonde have been used with considerable success. Figure 6 is an illustration of a profile obtained of a river bottom. The record is split around the coring which is used to confirm the interpretation of the record and provide evidence of the existence of the sought-after mineral. Magnetometers With the advent of the fluxgate, proton precession and lately, the rubidium vapor magnetometer, all measuring the earth's total magnetic field to a high degree of accuracy, this instrument has become much more useful in the field of mineral exploration. Anomalies indicative of mineralization such as magnetic bodies, concentrations of magnetic sands and certain structural features can be detected. Although all three types are adaptable to undersea survey work, the precession magnetometer is more sensi- tive and more easily handled than the Fluxgale, and the rubidium vapor type has an extreme degree of sensitivity which enhances its usefulness when working from the sea surface. Of those manufactured in the United States, the Varian range is considered very highly for marine work. EVALUATION OF THE ORE BODY Once an ore body is indicated by geological, geophysical or other means, the next step is to sample it in area and in depth. Systems for Sub-Bottom Sampling Sub-bottom sampling systems (Table 4), may be classified by the method of penetration of the bottom. (Figure 7) Impulsive Penetration is actuated by gravity, hydrostatic pressure, or explosion and takes place in one motion. Percussive Penetrative force is applied as a repetitive impulsive load. The frequency of the impulse may vary from a few cycles per minute as in the churn drill to several thousand blows per min- ute in the high speed, hard rock,percussion drills. The applica- tion of the latter type of machine offshore has been restricted to blast hole drilling. Vibratory All material has a natural frequency of vibration related to the velocity of sound waves through it. The application of a 95 WATER WUOM ~~CORING 50 ISO05 200 50TT20 U- LU5 WATER -. lo COBBLES, BOULDERS, CLAYEY SAND, GRAVEL- Iz SOFT CLAY, SAND AND GRAVEL - 200 ~~~~~~~ANDESITE ROCK - 201 SPARKER RECORD OF LOCATION OF BOREHOLE Figure 6 *TABLE OF SUB-BOTTOM SAMPLING SYSTEMS Depth of Depth of Diameter Power Oper- Type of Name Manufacturer Water Hole ft. Hole in. Reqmts. Platform ators Ground Impulsive Kullenburg Corer No limit 100 2-1/2 Gravity & Ship 2 Mud Hydrostatic Phleger Corer Hydro Products, No limit 2 1-3/8 Gravity Ship 1 Mud Calif. Box Corer Hydro Werkstatten, No limit 6 12 Gravity Ship 1 Sand W.G. Moore Free Corer Hydro Products, No limit 10 2-5/8 Gravity Free 1 Mud Calif. Percussive 9P Becker Hammer Becker Mfg. & 100' 150' hole corer.-500 HP Barge 13 Over- Drill BDT 150 Drilling Inc. Can. (5-1/2" o.d. burden <3' o.d.) Hyd. Jet Sampler U.S.B.M. - < 100' 1-13/16o.dK10 HP - 2 Over- (EX) burden 60 L Spudder Bucyrus Erie, - 1500' 6-8" 65 HP 2 Over- Wisc. burden & Sed 28 L Spudder Bucyrus Erie, - 2500' to 15" 78 HP 2 Over- Wisc. : burden & Sad 36 L Spudder Bucyrus Erie, - 3500' to 15" 175 HP 2 Over- Wisc. burden & Sed Table 4 *TABLE OF SUB-BOTTOM SAMPLING SYSTEMS Depth of Depth of Diameter Power -Oper- Type of Name Manufacturer Water Hole ft. Hole in. Reqmts. Platform ators Ground 48 L Spudder Bucyrus Erie, - 6000' to 15" 219 HP 3 Over- Wisc. burden & Sed Vibratory Vibracore Alpine Geophysical < 600 < 16 1-3/8" Air Vibrator Ship 3 Unconsol. Ass. N. J. < 6" o.d. Seds. Vibratory Corer Ocean Science & < 200 20' 2-1/2" i.d. Batteries Ship 2 Unconsol. Eng. Co. Calif. 15-20 HP Seds. Deep Corer Ocean Science & 150' 100' 6-5/8"o.d. 320 HP Ship 100' Over- Eng. Co. Calif. Diesel Hydro burden Sub Core Drill Geo. Wimpey & Co. 200' 20' 3" N.K. Bottom 2+ Consol. U.K. diver Underwater Drill Acker Drill Co. 60' 24' 12" Air Barge 4+ Cast Iron Inc. Pa. diver Flexo Drill Institut Francais 600' 100' 6" 25 HP Elec- Bottom 2 Consol. du Petrole tro Drill Terebel Institut Francais 3000' 3280' 8" 300 HP Drill Consol. du Petrole Diesel Hydro Ship 250 HP Diesel Elec Turbodrill Dresser Industries 12000' 23000' 2" core Mohole Consol. 10" o.d. Submergible Koken Boring Co. > 600' 45' 1-5/8" 5 HP Bottom Consol. Core Drill Japan Electric Table 4 (Contd) *TABLE OF SUB-BOTTOM SAMPLING SYSTMS Name Manufacturer Depth of Depth of Diameter Power Oper- Type of Name Manufacturer Water Hole ft. Hole in. Reqmts. Platform ators Ground Marine Rotary LMSC/IMC 600' 8' 2-1/4" o.d. 3 HP Bottom 2 Consol. Corer Electric Rockeater Ocean Science & < 200' 20' 27" 500 HP Drill Over- Eng. S.A. Diesel Ship burden Electric Glomar Sirte Global Marine Exp. 600' 20000' to 15" Steam Drill Consol. Calif. Ship Glomar IV Global Marine Exp. - 20000' to 15" Diesel Drill Consol. Calif. Ship Glomar III Global Marine Exp. - 20000' to 15" Diesel Drill Consol. Calif. Ship Glomar Global Marine Exp. > 600' 20000' Drill Consol. Calif. Ship Cuss I Global Marine Exp. 12000' > 600' Drill Consol. Calif. Ship Rincon Global Marine Exp. 250' 6000' Drill Consol. Calif. Ship Western Expl. Global Marine Exp. 250' 6000' Drill Consol. Calif. Ship Submarex Global Marine Exp. 1500' 25000' Drill Consol. Calif. Ship La Ciencia Global Marine Exp. Drill Consol. Calif. Ship Table 4 (Contd) *TABLE OF SUB-BOTTOM SAMPLING SYSTEMS Depth of Depth of Diameter Power Oper- Type of Name Manufacturer Water Hole ft. Hole in. Reqmts. Platform ators Ground Oscillatory Beach Corer Ocean Science & - 15' 361 N.K. Tractor 1 Over- Eng. S.A. burden Jetted Hydrop Alluvial Mng. & 200' 20' 36" 500 HP Bottom 3 Unconsol. Shaft Sinking Co., Diesel U.K. Hydr. Hydroprobe LMSC/IMC/MMTC 150' 15' 3-1/2"o.d. 15 HP Bottom 2 Unconsol. Air Hydr. Combination Banka Drill Conrad Stork, 30' 100' 4"l-6" 8 men Raft 8 Over- Holland burden Overburden Drill Atlas Copco, 30' 150' 5" 500 HP Raft 2 Over- Sweden Diesel Air. burden Benoto Hammer Sir Bruce While, 50' > 100' 14-55" > 500 HP Pontoon 3 Over- Grab Wolfe, Barry & burden Partners U. K. & rock *Based upon information published or made available by the manufacturer. Table 4 (Contd) AMPLING TO IMPULSE PERCUSSION VIBRATION ROTATION OSCILLATION JETTING COMBINATION PHLEGER BECKER ALPINE LMSC/IMC O. S. E. ALLUVIAL ATLAS COPCO CORER OVERBURDEN ALPIN ROTARY ROCKEATER MINING OVERBURDEN GDRILL VIBRACORE CORER DRILL I4VDROP DRILL HAMMER PUP MTRWTR CM OAMMERTO H WATER COMP HIGH- PRESSURE WATER JETS Figure 7 continuous vibrational impulse to a coring tube or rod will assist it to penetrate at rates which are partially dependent on the frequency of vibration. Such methods have been used in pile driving with success and more recently in core drilling in sands and unconsolidated material. Much has still to be learned about the relationships between the factors involved such as the vibrational amplitude and frequency, and the physical properties of the material, but the method has encouraging possibilities. Rotary Rotary drilling is the most widely applied method of ground penetration outside of the mining industry. A steady thrust is applied to a continuously rotating drill bit which may be of solid, annular or auger type. All types of ground may be pen- etrated by rotary drilling, the applied variables being the type of bit, the speed of rotation and the thrust. Oscillatory Oscillation of an annular core barrel under a steady thrust may assist penetration. It is rarely used because of its limited advantages over rotation. Jetted If high pressure Jets of water or air are allowed to impinge on unconsolidated material, an excavation will be formed. Controlled penetration of a sample tube may be achieved by this method. Combination Any of the above methods may be combined to take advantage 6f the best features for particular types of ground. Percussion and rotation are frequently combined both, generally, increasing in rate with increasingly hard ground. As penetration of the sampling mechanism is effected, it is necessary to remove the material from the hole. The material, which constitutes the sample may be in the form of dry cuttings, wet slurry or solid core. This may be flushed continuously from the hole with air or water or it may be removed intermittently with a bailer or grab. (Figure 8) In normal flushing, the cuttings or mud are forced up the annulus between the drill rod and the sides of the hole. In reverse flushing which has gained rapidly in popular use, the material is removed from the hole through the center of the drill string. The center hole generally has a smaller area than the annulus, hence velocities are greater; there is less mixing of the sample and no contamination from the sides of the hole. Solid cores are removed intermittently in rigid core barrels or in some cases continuously in a form of flexible sleeve. In loose or soft ground, samples are badly disturbed by the movement of the core barrel and successful coring requires not only special equipment such as the rubber sleeve core barrel (Christensen), but con- siderable drilling skill as well. Once removed from the hole, the collection and reorientation of the sample relative to its position in the ground is necessary, particularly in the valuation of ores. With solid cores this is no particular problem, but with loose material it can be a very 102 SAMPINGT CONTI N UOUS REPETITIVE NORMAL FLUSH REVERSE FLUSH BAILING CORING I SUCTION PUMP I iBUCKET WIRELINE AIR, WATER PUMP ON Y~~oll MUD IR E LINE ORRODS SuMP CYCLONE ' . . FOR FOR REMOVAL CUTTINGS OF CUTTINGS CASING DRIVEN AHEAD OF BAILER TO PREVENT ALL CUTTINGS TO SLOUGHING IN SOFT SURFACE THROUGH GROUND DRILL STEM Figure 8 major one. Taking intermittent samples of the material as it comes out is satisfactory for some purposes, but where a com- plete and continuous record is required, reverse flushing and removal of the cuttings by cyclones offers a satisfactory solution. Sampling equipment should be chosen, developed or designed for a specific set of conditions and the sampling system may incor- porate any combination of the above methods of penetration, removal and collection of the material. Major variables to be considered are ground type, mineral type, depth of hole, depth of water and reliability required. No one machine will suit all conditions and it would be optimistic to assume that one could be built. In general, the more valuable the mineral, the less prolific it is and the greater is the volume of sample required. Diamonds are an extreme example of this situation, and large diameter rotary drills or jetting devices are required for high volume sampling. Extremely heavy minerals, such as gold and the platinum group, are greatly affected by pounding and vibration which causes them to migrate in the vicinity of the hole causing dilution or salting of the sample. For placer deposit sampling on land, the low speed rotary percus- sive drill (Banka type) appears to have the best record for accuracy. It is essential when sampling unconsolidated material of this nature that the hole be cased, and that the casing be driven well in advance of the cutting tool. The presence of boulders or buried tree stumps, common in many alluvial deposits, increases the difficulties of obtaining an accurate sample. Most of these problems are enhanced when working offshore, although some of them, such as the presence of a water table interface, always a problem when sampling unconsolidated materials, are eliminated altogether. No doubt the greatest question mark lies with the method of mounting the sampling device. Most adaptations of land sampling systems are mounted on a drilling vessel. The trend may be toward self-contained sampling devices which rest on the bottom, with only a flexible line connecting them with their control vessel. Several excellent systems of this kind are in use and they are particularly adaptable to rough water - the greatest deterrent to drilling at sea. One simple axiom is obvious; if it will not sample accurately on land it will not sample accurately at sea so adequate controlled testing prior to its use at sea is of prime importance. There are at least 25 different basic designs of sampling equipment available at the present time, and over 150 manufacturers are listed in the mining literature alone. Many more are listed in the civil engineering, petroleum industry, and oceanographic literature. There is little in the way of hardware which has not already been thought of, if not built. The fullest use should be made of existing material, but the ultimate choice will depend on the specific sampling problem to be resolved. Some of the sampling systems in Table 4 which are of particular interest are discussed below. Becker Overburden Drill The Becker BDT 150 was designed specifically for overburden drilling. It consists of a double walled drive pipe 5-1/2", o.d. and 3" i.d. overall. The pipe is driven into the ground by means of a diesel operated hammer mounted on top of it. Air or water is injected down the annulus between the inner and outer pipe and is jetted inside the casing a few inches above the 104 cutting shoe. The cuttings are carried by the air or water up through the inner pipe and are discharged and collected at the top in a cyclonic separator. The center tube is continuously open, and tube samples may be taken at any time by dropping a tube or wire line corer down from the surface. This drill has been adapted for offshore work and gives a measured 80-100% sample recovery. The accuracy of the sampling has not been proven at sea, but it is assumed to be high. Penetration rates are high, averaging 100 feet per hour in gravels, sands and boulders. At Nome, sampling gold deposits, Shell drilled through 50 feet of ice and water into 60 feet of gravel, boulders and sand on the ocean floor. Although core recovery was 80% complete, the extent of the gold recovery cannot be estimated. A barge mounted unit is also engaged offshore in Thailand sampling cas- siterite deposits. Up to 70 feet of overburden is being drilled through 95 feet of water and recoveries of 85% reported. There are two major problems in using this drill offshore. One is the necessity for very calm waters due to the bulk and unwieldiness of the surface rig. Wave height of 2' are reported as a safe maximum. The other is the difficulty in retracting the drill. The hammer action is not reversible and jacks are used to ply the pipe from the hole. In Thailand it was not possible to use the barge for leverage because of the danger of sinking it. A large foot pad and casing pipe resting on the sea floor, was set over the drill, and the top of the casing which projected above the water surface, used as the lever fulcrum. This is a fast acting sampler but its small diameter and pounding action may limit its accuracy in the sampling of precious metals. O.S.E. Deep Corer The O.S.E. ship mounted system uses a rotary hydraulic vibrator which is clamped to the casing. The clamp has the advantage of keeping the top of the casing open at all times for wire line coring. Air or hydraulic bailing can be accomplished within the 6-inch casing using flexible hoses. The entire rig is operated by 8, 45 gpm, 2000 psig diesel hydraulic pumps. The vibrating head and power tongs are raised in the derrick by means of a hydraulic ram mounted in the main skid. Cables in the derrick are attached to a yoke on the ram. The hydraulic ram is linked to a wave compensating device. Vibration is variable up to 80 cycles per second and 100,000 lbs. impaction. Penetration is expected to exceed 100 feet in semi-consolidated gravels. A hydraulic power swivel is used for making and breaking joints and also allows rotary drilling without vibration if desired. The casing is removed from the hole by reversing the vibratory action. Although the rig is not yet completed, it incorporates several unique features and promises to be a useful addition to marine sampling hardware. Submergible Core Drills There are several drills of this nature presently available, notably those manufactured by Geo. Wimpey & Co., Great Britain, Koken Boring Co., Japan, and Lockheed Missiles & Space Co./ International Minerals & Chemical Corp./U.S. Bureau of Mines consortium in the United States. They are all essentially a simple self contained rotary core drill mounted in a framework which can be lowered to the sea floor and powered from the sur- face ship. They vary in detail only, and are capable of taking cores in all materials as on land. They are all limited by their small dimensions. 105 Flexo Drill Some 30 years ago, a bottom hole drill with a flexible drill pipe wound on a reel, drilled to a depth of 2000 feet. Lacking a suitable down-hole motor, the system was not further developed, until the Flexo-drill designed by the Institut Francais du Petrole. The system comprises a down hole motor, weight, and drilling bit, a flexible drill stem, equipment for winding and handling the drill stem and equipment for surveying operations. Two units have been constructed - one, self contained except for the electric power supply, which operates on the sea floor and the other which is ship mounted and used a turbo-drill. Both systems have been successfully tested and are most suitable for consolidated material. O.S.E. Rockeater Drill This drill designed for the sampling of alluvial diamond deposits at total depths of less than 100 feet has the capability of rotation as well as oscillation. It is capable also of jetting and removing the sample by reverse flush methods. In normal working, a 27 inch diameter core was removed from maximum depth of 20 feet of overburden. Hydraulic Probes A number of these rigs are now available and give exceptionally good results where they have been used in unconsolidated sedi- ments, sands and gravels. They consist of a heavy steel casing fitted with high pressure water Jets at the shoe, vibratory devices, to aid penetration, and a water venturi, air lift and/ or suction lift to raise the material from within the casing to surface. Penetration and discharge of the sample are continuous. Adaptations of this method with large diameter casings (up to 6') and diver-held pumps also have been used successfully in shallow deposits. Banka Type Drill These consist of a casing, generally 4" to 6" in diameter, which is caused to penetrate overburden by rotating with a heavily applied static down thrust. Removal of the sample from within the casing is by bucket pump, bailer or grab. These machines are generally manpowered but, in the evaluation of placer mineral deposits are highly efficient. This is no doubt due to the slow movement of the mechanism which does not disturb the ground through which it passes. Mechanized editions are available and are used successfully. EXTRACTION OF THE ORE While the mineral deposits of the continental shelf include both consolidated and unconsolidated materials as well as oil and gas, we give consideration here only to the unconsolidated mineral deposits derived from continental sources and located in marine beaches and nearshore areas. There are at least 70 minerals which may be concentrated in alluvial deposits. Most of them are heavy and have a high resistance to weathering. Mineral deposits will vary, one from the other, and the choice of mining method will depend on many factors. These include the size and nature of the deposit, the nature and depth of the over- burden including water cover, the relation of the ore to bedrock, 106 DREDGES WHICH OPERATE HYDRAULICALLY - ~ ~~~~~~7HYD~~~~~~~~RAULIC PIPELINE DUSTPAN DREDGE SELF- PROPELLED CUTTERHEAD DREDGE HOPPER DREDGE DREDGES WHICH OPERATE MECHANICALLY IBUCKET-LADDER DIPPER DREDGE CLAMSHELL DREDGE Figure 9 TYPE OF DREDGE1 PBUCKET LADDER DRAGLINE CLAMSHELL HYDRAULIC* AIR LIFT* HYDRO JET' I DETAIL OF HEAD& WORKING DEPTH (M 30-100 0-5000 60-200 30-100 60-1500 O - ;200 NATURE OF BOTTOM MED HARD ROCK UNCONSOLIDATED UINCONSOLIDATED MED HARD ROCK UNCONSOLIDATED UNCONSOLIDATED THROUGHPUT YDVH 100-2500 1-400 60-1500 60-4500 I-8OO 150-4000 COST PER YDNY"t 3.4-62 .450 4.4-28 10 -19 e 100 4 2.5 -6.0 CAPITAL COST (4) 1-3M LOW ~50O.OOO 5000-3M UP TO I.7M 25,000 -I.3M * EACH OF THESE SYSTEMS MAY BE USED WITH OR WITH4OUT A CUTTER HEAD **COSTS ARE FOR ACTUAL OPERATIONS AT LESS THAN 200 FOOT DEPTHS Figure 10 *DATA ON OPERATING DREDGES Total Thru- Dredge Op. Put Cu. Yd. Cost/Yd. Company Type Capacity Capital Cost Area Period Depth Solids Cents Bucket Line Yukon Gold Copr. Au Bucket 13.5 ft3 Colombia 1962 91 5,934�,o0 6.4 Ltd. Patio Con- Line solidated Au Bucket 11 ft3 $2,090,426 Narino, 1963 54 , 1,750,000 62.4 Line Bolivia Tongkah Harbor Sn Bucket 15 ft3 _ _ Line Indonesian State Sn Bucket 14 ft3 2,800,000 Billiton 60-100 Mines Line & Singkep Tronoh Mines, Sn Bucket (x4) 1963 10,974,000 13.4 Ltd. Line Ayer Hitam Sn Bucket (x2) Selanger 1963 Deep 6,922,000 15.3 Line Malaya Sn Bucket 1961 Deep 5,289,000 20.4 Line TanJong Sn Bucket Perak, 1963 2,026,000 18.8 Line (xl) Malaya Petaling Sn Bucket Selangor 1964 8,298,000 20.2 Line (x5) Grab Aokam Tin Sn Grab 4 yd3 Phuket 100-120' 1,500,000 28.3 Yawata Iron & Fe Grab 10.5 yd3 Ariake 1962 45 27.7 Steel Bay Table 5 -'DATA ON OPERATING DREDGES Total Thru- Dredge Op. Put Cu. Yd. Cost/Yd. Company Type Capacity Capital Cost Area Period Depth Solids Cents Karl Epple Co. S&G Grab 2.0 34,200 Germany 1962 33-132 .63- .34 m 7.0-14.2 Stutgart S&G Grab 4.8 106,000 Germany 33-132 2.60-1.30 m 4.4- 8.8 Suction U.S. Copr. of S & Suction 8-20"(x20) 636,000(xl) U.S.A. 55 110,000,000 10.9 Engineers Clay Alum Copr. of Overb. 24"Y 800,000 Surinam 45 1,800,000 19.6 Amer. Water Lift Phillips "Mud S&G Water 150 yd3/hr. 25,000 Calif. 1965 400(?) 111,500 6.o Hog" Lift Mining Equpt. S&G Hydro- 200 yd/hr. 100,000 United 1966 300 NK 3.0 (London) Ltd. pneu- Kingdom matic Combination Marine Diamonds Di Air/ 1,700,000 SW Africa 1963 1,404,000 122.0 Water Lift Terra Marina Di Air/ 400 m3 1,260,000 SE Africa 1965 Water solids/hr. Lift Kaiser S&G Suction/ 200 yd3/hr. 400,000 Ghana 1962 200 Construction Hydrojet *Based upon information published or made available by the manufacturer. Table 5 (Contd) production requirements, logistics, weather and sea states, and so on. These factors can only be ascertained after a thorough investigation of the particular ore body. In this case, we can only postulate an ore body and describe some of the methods from which a choice would be made. In deposits offshore, many adap- tations will be required of existing equipment and methods, but except in deep water, say beyond 200 feet, these would not re- quire any form of technological breakthrough. Types of Dredges Alluvial deposits offshore are mined by dredging using bucket ladders, draglines, clamshells, hydraulic dredges and air or water lift. None of these systems is new in concept and not all have been successfully used in mining operations, but each is applicable to particular cases. See Figures9 and 10 and Table 5. Bucket Ladder Dredges Mining with the bucket ladder is a continuous process with ex- cavation accomplished by using an endless chain of steel buckets which dig into the ground below the level of the floating dredge. This technique, used in many civil engineering and construction machines for excavating trenches for foundations, ditches, and canals, was possibly among the first of the automatic production lines. Bucket capacities of mining dredges vary from 2 to 20 cubic feet with up to 54 cubic feet proposed giving monthly capacities in the range of 60,000 to 1,500,000 cubic yards. Digging may be carried out to depths of 100 feet below water line and, on occa- sion, to 150 feet. Concentration of the mineral values is carried out on board the dredging vessel and tailings are discharged to the rear. Since most mining operations are carried out for high gravity minerals of low volumetric concentration, the tailings constitute the major part of the through-put of the plant. Dredging capacities are dependent on the bucket size, the horse- power, and the digging conditions. They normally average from about 150,000 to 400,000 cubic yards per month. Power on the dredge is required to actuate the bucket line, con- trol the winches, and run the pumps and other plant, such as trommels, jigs, and concentrating tables. Electric power is often supplied by cable from shore, but in out-of-the-way places, diesel electric plants and even steam generators are used. Draglines and Clamshells Because of its simplicity, the dragline is often used in the sampling of deep sea deposits, at depths as great as 30,000 feet; but there is no record of it being used for mining offshore, except in the recovery of beach sands above the high water mark. Recent studies indicate that as a method of commercial dredging for nodules in deep water, it might be applicable to a depth of 5,000 feet, but would not be efficient in cleaning the bottom. Very large and unwieldy buckets would be necessary for such an operation and control of the dredge sweeps would be difficult. Clamshells, or grab dredges, being suspended from wire ropes are similar in concept but are becoming much more widely thought of as a mining tool. Grabs were first introduced in 1865 and later the multiline grab was developed. Its great advantage was that it 111 could be opened underwater if caught on an obstruction. Since then, many general advances have been made in the design and digging efficiency of grabs, and today, the four-rope heavy excavating type can be regarded as one of the world's foremost digging tools. From a tonnage viewpoint, it probably handles more material than any other single mechanism. Outputs of 800 to 1,000 tph are common with a single grab, and 30-ton capacity grabs with outputs of 1,500 tph are already beyond the drawing board stage. Hydraulic Dredges The use of hydraulic dredges in mining is confined mainly to the removal of overburden in the mining of unconsolidated sand and gravel deposits. However, recent improvements in size and capacity of suction dredges for civil engineering has been sub- stantial. The increase in mining operations offshore and pro- posals to vacuum-clean the deep sea floor for nodules point to an inevitable revival of interest in the hydraulic dredge as a mining tool. One of the fundamental problems in suction dredging is the continuous entry of the maximum amount of solids into the suction pipe. Hydraulic (or suction) dredges may be built with or without cutter heads. Those with cutter heads are used to dig into consolidated alluvium or soft to medium hard rock, and those without cutter heads are used to remove unconsolidated sands, muds, and silts. Most mining operations use cutter heads to break up the ground and direct the flow of solids into the suction pipe. These heads are of various designs, but are normally of the rotating, hollow bit type, placed directly in front of the suction pipe. The pipe and rotating shaft are attached to a rigid ladder which is raised or lowered in front of the dredging vessel. Dredges are now built with a rotating suction pipe which has the cutter head directly attached. The dredging vessel is generally anchored at the stern by hawsers, or by spuds driven into the bottom and the vessel is swung in an arc from the point of anchorage, to give a maximum sweep to cutting head. Without the cutter head, various methods are utilized to gather the material into the suction pipe. The types of head in use include plain suction, the dust pan type, and the drag head. These are used from dredging vessels with the suction head held stationary, thrust forward, or dragged. Water jets to agitate the solids are often used with the plain suction head but they tend to agitate the lighter material and wash away the heavy minerals from the nozzle. A ladder mounting may be used for the suction pipe of the dust pan dredge, but drag heads are generally attached to a rigid suction pipe which swings down from the side of the vessel and is suspended at the head. Joints are also used where extra pipe flexibility is desirable. Suction dredges generally operate at depths of 30 to 90 feet, but are being built to operate at depths up to 250 feet. Preliminary designs have been made for hydraulic dredges to mine the nodular deposits at depths of 4,000 feet and greater. Velocity head and entrance loss to the suction pipe are independent of dredging depth, but at greater depths, increases in the friction head and in the head required to support and move the column of mixture, will obviously require the submergence of the pumping unit. Hydraulic dredges generally have a high capacity. A 10-inch dredge with 400 hp. on the pump and a 75 hp. cutter will con- servatively pump 250-cubic yards per hour in unconsolidated 112 material and 50 cubic yards in soft rock. A 30-inch dredge with 8,000 hp. on the pump 2,500 hp. on the cutter will pump 4,500 cubic yards per hour in unconsolidated materials and up to 2,000 cubic yards in soft to medium-hard rock. Operating costs will range from $15,000 a month of 22-hour days for the 10" dredge to $100,000 for the 30 inch. Capital costs are in the region of $225 to $275 per installed horsepower. Air Lifts The air lifts work on the principle that air injected into the bottom of a pipe, submerged at least 60% of its length in water, will produce a density differential in the pipe. The air-water mixture in the pipe will then flow upwards under the influence of the hydrostatic head and this flow will cause a suction at the bottom end of the pipe which can be very substantial. Air lifts have been used in the past for numerous civil engineering pro- Jects where simplicity of construction is the keynote. Since they consist of only two pipes, they may be constructed in any field shop and require only compressed air to operate. However they are extremely inefficient. Hydro-jet Dredges The hydro-jet employs the Venturi principle whereby a water jet at high pressure and high velocity is injected upwards into the dredge pipe near the head and a flow induced in the system. This may be supplemented by air injection or a centrifugal booster pump placed at a higher level. Because the jet pump is always at the bottom of the dredging ladder it can operate at any depth. It may therefore take over from the suction dredge at depths beyond the limit of the latter. Because the dredged material does not pass through the high pressure centrifugal pump and because high pressure cutter jets are normally incorporated to break up the ground being dredged, there are few wearing parts and subsequently maintenance costs are low. Several firms make dredges based on this principle and they are used for the mining of gold, sand and gravel. Small hand held units have been suc- cessfully operated by skin divers in the mining of gold from river bottoms in California and Colorado. In South West Africa, Marine Diamond Corporation has developed and successfully applied techniques for operating the hydro-jet in combination with air- lifts, and it is also used in combination with pump and airlift on the sampling vessel -Rockeater. Mixtures of up to 40% solids are not unusual with this system. Beneficiation At the present time, in most alluvial mining operations employing dredges, beneficiation is carried out on board the dredging vessel or on a floating barge nearby. The majority of these plants are maintained on enclosed ponds with little or no water motion. Because of the more violent motions of floating plat- forms in the open sea, beneficiation is restricted to those processes which do not require complete stability during their operation. Such processes as washing, sizing, comminution, flotation, amalgamation, course gravity and magnetic separation may all be adequately performed, while the use of tables, spirals, and standard magnetic and electrostatic sand separators would not be suitable without adaptation. Sea going plants are presently in use for the production of cas- siterite, magnetite, and diamond concentrates and for washed and 113 sized sands and gravels. In shallow water (less than 200 feet) Jack leg or similar platforms in contact with the bottom might be employed to obviate the effects of motion. TRANSPORTATION In the mining of offshore deposits, transportation becomes one of the lesser problems. Since the area is amenable to floating mining vessels, it also will allow for transportation by sea, and much advantage can be gained by the flexibility of this system. Pipe line discharge to the shore is sometimes used where it is expedient to have the material onshore, but in most cases the valuable concentrate is but a small portion of the material handled and more simple handling methods can be used. Despite the above, transportation factors should be given early consideration in the economic analysis of any deposit. Partic- ularly in remote areas, the cost of handling and transportation must be weighed against the cost of reducing the bulk by on site beneficiation. Many other factors, such as the availability of power, docking facilities, distance to smelter, and production rates will influence decisions in these matters. There are a variety of ore-carrying ships that should be adaptable with minor modifications. In summary, the exploration, ore delination and mining tasks vary considerably depending upon the sea environment, sub soil and ore body characteristics. Considering these factors, there exists a considerable variety of equipment that has application to undersea mining. Some equipment such as that used to accom- plish precision navigation, position keeping, and sub-bottom profiling are adequate for the tasks on the continental shelves. More limited in capability are present dredge and coring systems. However, continued experience in operations with existing hard- ware will form the basis for modification and development of more efficient and specialized systems. BIBLIOGRAPHY Baker, Geo.; 1962, Detrital heavy minerals in natural accumulates: Aust. Inst. of Mining & Metall. 146 pp Bigelow, H. W.; 1964, Electronic positioning systems: Undersea Technology, v. 5, n 4, p. 24-28 Bruckshaw, J. M.; 1961, The work of the channel tunnel study group, 1958-60 Inst. of Civil Engineers, proc. v. 18, p. 149-78, paper no. 6509 Cruickshank, M. J.; 1962, The exploration and exploitation of offshore mineral deposits: Colorado School of Mines, M.S. Thesis no. 969 185 p. 1964, Mining offshore alluvials: Symp. on Opencast mining, quarrying and alluvial mining. London, Inst. of.Min. & Met. Nov. Paper 7, 31 p. Delacour, J.; 1965, Flexo drill. A new method applicable to offshore: 1st International Con- gress "Petroleum & the Sea" Monaco. 114 Erickson, Ole P.; 1961, Latest dredging practice: Journal of the Waterways and Harbors Division, Proceedings of the Am. Soc. of Civ. Eng. v. 87, Feb. 1961, paper 2729, p. 15-28 il. Harding, H. J. B.; 1949, Site investigations including boring and other methods of subsurface explora- tion: J. Inst. Civil Eng. v. 32, p.111 Hill, J. C.; 1964, Jet pumps in dredging operations: The Military Engineer, No. 373. Sept-Oct. 1964, p. 333-5 Hill, J. C. C.; 1965, Underwater sampling techniques are most important steps for underwater mining: World Mining, July, p. 32-5, v. 18, n. 8 Hopkins, T. L.; 1964, A survey of marine bottom samplers: From Progress in Oceanography v. 2, ed. Sears. Macmillan Co. N.Y. p. 215-56 Hvorslev, M. J.; 1949, Subsurface exploration and sampling of soils for civil engineering purposes: Waterways experiment station. Vicksburg, Miss. Hydrospace buyer's guide: 1808 Wisconsin Ave. N.W., Washington D.C. $10 Ledgerwood, L. W.; 1961, Efforts to develop improved oilwell drilling methods: Colorado School of Mines, quarterly, v. 56, n. 1, p.37-77 Low, D. W.; 1952, Dredging craft: Engineering v. 173, no. 4496-7. March 21-28, 1952. p. 344 sig. ill. Romanowitz, C. M.; 1962, The dredge of tomorrow; Eng. & Mining Journal, v. 163, n. 4, p. 84-91, April U.S. Army Corps of Engineers, 1954, The hopper dredge, its history, development and operation; Washington U.S. Government Printing Office. U.S.N.C.E.L.; 1964, Structures in deep ocean engineering, manual for underwater construction, Chapter 3, reconnaissance and position- ing: U.S. Naval Civil Engineering Lab., California Webb, B., 1965, Technology of Sea Diamond Mining: MTS/ ASLO, Ocean Science & Ocean Engineering Conference, June 1965, v. 1, p. 8-23 PETROLEUM RESOURCES OF THE CONTINENTAL MARGINS OF THE UNITED STATES By T. W. Nelson and C. A. Burk Socony Mobil Oil Company, Inc. Abstract Only a small part of the continental margins of the United States can be credited at the present time with potentially large accu- mulations of petroleum; however very little of the total area is known to be non-prospective. Estimates of this petroleum potential vary greatly, reflecting our poor understanding of the geologic structure and geologic history of these offshore areas and the difficulties inherent in guessing the amounts of any undiscovered mineral resource. Approximately 2 billion barrels of petroleum liquids and 5-1/2 trillion feet3 of natural gas have already been produced from the U. S. continental shelves, and another 3-1/2 billion barrels and 22-3/4 trillion feet3 have been proved by drilling. An additional 3 billion barrels and 27 trillion feet3 probably await drilling in known reservoirs, and it is possible that 8 to 26 billion barrels and 33 to 113 trillion feet3 remain to be discovered. The ultimate petroleum potential of the U. S. shelves may thus range from more than 15 to 35 billion barrels of petroleum liquids, and from 90 to 170 trillion feet3 of natural gas. The volume of petroleum ultimately produced will depend largely, however, on our ability to explore and produce it and the economic incentives to do so. To date, the petroleum industry has drilled more than 8,250 wells offshore, has invested more than $6 billion in these marine efforts, and has accounted for more than $3-1/2 billion in direct payments to federal and state treasuries. Petroleum exploration and pro- duction is at best an expensive and risky business, and immense sums of money will be needed for future marine ventures. However, we have every reason to expect a continued expansion of effort in finding and recovering our marine petroleum resources. GENERAL ASPECTS OF U. S. CONTINENTAL MARGINS The surface of the earth consists essentially of two topographic surfaces - the average height of the continents and the general depth of the ocean basins. The boundaries between these areas comprise the continental margins of the world. They are among the principal geologic features of the earth, but they are probably the most poorly understood. The volume of water now in the oceans slightly exceeds the capacity of the ocean basins, and it is even possible that the broad continental shelves which we see today are unique in the history of the earth (Figure 1). The seaward edge of the continental shelf is normallyr marked by a sharp increase in slope, known as the "shelf edge.' By con- vention the edge of the shelf is considered to be at 100 fathoms, but in fact it ranges from less than this to much more. The steeper surface beyond the shelf is the "continental slope,"I normally considered to extend to a depth of about 1,000 fathoms, beyond which the more gentle surface of the "continental rise" ideally slopes into the deep ocean basins. 116 i 0 500 I000 "'' .. . FIG. I MAP OF U.S. CONTINENTAL MARGINS, SHOWING ADJACENT AREAS OF PETROLEUM PRODUCTION. CAPE KENNEDY LONG BEACH COOK INLET METERS FEET NEW ORLEANS I NEW YORK M R o' I ! I/ , -� \1' --'- L''""~E:-...."~_.~~ X~'~'~.~ \ - -1000 -5,000 'l I~ --32000 -10o,ooo' 000 ... --3000.. . "'- --7s---- . .. -~~- --4000 -15,000 ~.-. ._- -- '-. , ' . . ! ,.. . , ...--5000 0 50 100 150 200 250 300 350 400 450 NAUTICAL MILES WATER DEPTH AND AREA (IN THOUS. MILES2) i. 0-200M 200-1,000M 1,000-2,000M TOTAL 0' ATLANTIC MARGIN 124 28 12 164 FLORIDA MARGIN 78 51 18 147 GULF OF MEXICO 68 27 33 128 (LOUISIANA) (25) (10) (10) (45) PACIFIC MARGIN 23 27 26 76 ALASKA PACIFIC 82 29 13 124 (GULF OF ALASKA) (25) (7) (3) (35) ALEUTIAN SHELVES 16 28 28 72 BERING SEA SHELF 364 10 10 384 (BRISTOL BAY) (50) (1) (I) (52) ARCTIC MARGIN 120 55 100 275 TOTAL 875 255 240 1,370 FIG. 2-TOPOGRAPHIC PROFILES AND AREAS OF U.S. CONTINENTAL MARGINS. Only the northern Atlantic Seaboard in the United States approx- imates this ideal continental margin (Figure 2); all of the others are distinct. A broad borderland at a depth of about 500 fathoms adjoins the east Florida shelf; the floor of the northern Gulf of Mexico slopes gently to even greater depths beyond the shelf break; isolated depressions at depths to 1,000 fathoms occur within the continental margin off southern California. Each of these variations is a result of a different geologic history and geologic structure, and each area poses distinct problems for the exploration and development of its petroleum resources. There are approximately 875,000 miles2 of continental shelf bordering the United States. An added 495,000 miles2 lies in waters between 100 and 1000 fathoms. The geology is almost en- tirely unknown beyond the continental shelf, and estimates of the petroleum potential of these outer areas are presently beyond reasonable speculation. NATURE OF PETROLEUM AND PETROLEUM RESERVES One of the most important aspects of petroleum is that it occurs as a liquid or a gas, and as such it is free to move easily through the porous rocks of the earth's crust. This freedom of migration obviously complicates exploration, but it also allows petroleum to accumulate in local traps in quantities large enough to justify extraction - just as the schooling of herring allows them to be extracted from the sea economically. The total volume of oil or gas in any local accumulation is commonly known as petroleum "win place." The amount of this petro- leum that can be recovered depends largely upon three factors: P l- the nature of the reservoir rock, the type and compo- Mtinc or the petroleum, the source of pressures within the reservoir,, etc.; Technologi the engineering techniques available for drilling and hepetroleum under a variety of adverse conditions; Economic - the cost of exploring, drilling, producing, transporting7ThefTing, and marketing the petroleum, as compared with its worth or market price. The volume of recoverable petroleum from any reservoir is the ''recoverable reserves." Obviously the volume of any petroleum already recovered from a reservoir is the most accurately known component of the ultimate reserves. Some of the remaining reserves have been "proved" by the drilling of wells; these also are known fairly accurately. Less accurate are estimates of recoverable reserves in undrilled parts of the reservoir and reserves available by improved recovery techniques yet to be applied. These are known as "prospective reserves."t The least accurate estimates are of recoverable reserves in accumulations that have not yet been found. These are "specu- lative reserves," and obviously they are most speculative in regions where there has been no drilling. Thus, in estimating the ultimate recoverable petroleum reserves of any area, we are faced with reliabilities ranging from known volumes already produced to highly speculative estimates of yet- to-be-found accumulations. Without question, the continental margins of the United States fall very largely in the unknown and highly speculative category. PUBLISHED ESTIMATES OF ULTIMATE PETROLEUM RESERVES Inasmuch as the geology of continental margins is very poorly known, and the technology and economics of operating in these areas is very problematical, it is reasonable to expect that 119 ULTIMATE OFFSHORE OIL AND N.G.L. RESERVES ( BILL IONS OF BARRELS I ATLANTIC GULF UNITED NORTH COAST CALIF. COAST STATES AMERICA WORLD PRATT, 1947 (33) 1000 WEEKS, 1950 400 U.S.G.S., 1951,1954 > 1 >15 EGLOFF, 1952 (50-100) (500-1000) SCHULTZ, 1952 <30 CARMICAL, 1955>5 HUBBERT, 1956 20 ATWATER, 1959 35L. JOHNSTON, ET AL, 1959 7.7 HUBBERT, 1962,1965 (25) 400 WEEKS, 1965 (137) TOO RUBEL, 1966 >7 ULTIMATE OFFSHORE NATURAL GAS RESERVES (TRILLIONS OF CUBIC FEET) ATLANTIC GULF UNITED NORTH COAST CALIF. COAST STATES AMERICA WORLD TERRY, 1950 5 U.S.G.S., 1954 3.5 65 6S.5 KASTROP, 1955 (70) HUBBERT, 1956 (ISO) ATWATER, 1959 > 21.5(Lo.) JOHNSTON, ET AL, 1959 46.2 HUBBERT, 1962,1965 (125-150) WEEKS, 1965 (348) (1,740) RECENT ESTIMATES OF TOTAL RESOURCES U. S. TOTAL WORLD TOTAL O L CX 109BBLS.) GAS (X 1012FT.3)] OIL(X 109BBLS.) GAS (X 1 12 FT.3) HUBBERT, 1962,1965 205 1,000 1,500 7,500 HENDRICKS, 1965 460 2,000 (2,900) (15,000) WEEKS, 1965 (OFFSHORE ONLY) 1,000 (1,740) FIG. 3- PUBLISHED ESTIMATES OF OFFSHORE PETROLEUM RESOURCES. Figure 3 120 estimates of potential reserves should vary widely and that they should be based on a variety of techniques and assumptions (Figure 3). The available information dates from 1947 when W. E. Pratt estimated that the continental shelves of the world might yield as much as a trillion barrels of oil. Shurr and others (1960) interpreted this estimate as indicating that the proportionate share for the U. S. (excluding Alaska) is 33 billion barrels. Since 1947, there have been numerous estimates directly and indirectly related to the continental shelves of the United States. These estimates range from 15 to 100 billion barrels with the majority being in the range 20 to 30 billion barrels. With regard to natural gas reserves on the U. S. continental margins, the published estimates date from 1950 and range from 50 to 150 trillion feet3 with a mean figure of 100 trillion feet3. To put these estimates in perspective, they should be considered in the light of recent estimates of the ultimate petroleum poten- tial for the entire U.S., including the continental shelves. Hubbert (1962, 1965) has estimated this to be 205 billion barrels of liquids and 1000 trillion feetj of natural gas (excluding Alaska). On the basis of the published estimates and the mean figures cited above, 10-15% of the ultimate U. S. oil reserves and 10% of the ultimate U. S. gas reserves would appear to be on the continental shelves. Another recent estimate of ultimate U. S. oil and gas reserves has been made by Hendricks of the U.S.G.S. (1965). His estimates are more than twice those of Hubbert's, which would reduce the continental shelf percentages considerably. However, Hendricks' estimates appear to be unrealistically high. Weeks (1965) has estimated the world's offshore petroleum potential to a water depth of 1000 feet at 1000 billion barrels of petroleum liquids and 1740 trillion feet3 of natural gas (on BTU oil-equiva- lent basis). Each of the estimates shown in Figure 3 is based on different factors and flavored with differing personal opinions, so that it is difficult if not impossible to compare one directly with another. However, the great range in estimates fairly reflects our ability to guess the ultimate reserves of the continental shelves. There is always a tendency to make dogmatic statistical projections simply because it is uncomfortable to have to work with uncertain- ties, but unfortunately there is no known method for making en- tirely reliable estimates in unexplored areas. The human factors of experience and judgment become especially important in such cases. CUMULATIVE PRODUCTION AND PROVED RESERVES Most of the offshore production to date has resulted from the seaward extension of known petroleum areas; in fact many of the reservoirs are partly beneath the water and partly under land. Obviously it is difficult in such cases to separate offshore reserves and production from those onshore. For our broader pur- poses, such distinctions are somewhat academic since a change in sea level of only a few tens of feet would radically change these figures at the present time. Note: Offshore statistics commonly are not available separately from adjacent onshore areas, and it has been necessary here to abstract and approximate these data from many sources. 121 PETROLEUM LIQUIDS GULF COAST R/E// REMI/////////IIIIIING;jllli l CALI FORNIA //,/III ,!,,i, ALASKA IIIII 0 I 2 3 BILLIONS OFBARRELS NATURAL GAS GULF COAST FIl/////////.l.ll.lRED:"..". l"..i.|i.i. CALIFORNIA J ALASKA I do 0 5 10 15 20 25 TRILLIONS OF CUB/C FEET PROVED PETROLEUM RESERVES PETROLEUM LIQUIDS (MM BBLS.) NATURAL GAS (BILLIONS CU.FT.) CUMULATIVE REMAINING TOTAL CUMULATIVE REMAINING TOTAL GULF COAST 1,116 2,177 3,293 4,958 21,700 26,658 CALIFORNIA 800 1,400 2,200 500 1,000 1,500 ALASKA - 100 100 -50 50 TOTAL 1,916 3,677 5,593 5,458 22,750 28,208 FIG. 4 -PROVED PETROLEUM RESERVES OF THE U.S. CONTINENTAL MARGINS. PETROLEUM POTENTIAL OF U.S. SHELVES LOUISIANA- TEXAS SO. CALIFORNIA [ COOK INLET N t CD- POSSIBLE PETROLEUM RESERVES BRISTOL BAY > REMAINING TO BE FOUND AND PROVED GULF OF ALASKA ~ ]', m PETROLEUM LIQUIDS OREGON-WASH. 7.5 -26.0 SPECULATIVE OREGO N-UWA H. Ad-l~ + 3.0 + 3.0 PROSPECTIVE NO. CALIFORNIA g@� 10.5 - 29.0 BILLION BBLS. Trrrn>> NATURAL GAS FLORIDA SHELVES NATURAL GAS FLORIDA SHELVES ti[, 33.0 - 113.0 SPECULATIVE ATLANTIC SEABOARD +27.0 +27.0 PROSPECTIVE 60.0- 140.0 TRILLION CU.FT. aBLL/ONS eBLS. a I 2 3 4 5 6 7 8 9 10 11 12 TRILLIONS CFr 0 10 20 30 40 50 60 70 80 90 100 110 120 LIQUIDS (BILLIONS BBLS.) GAS (TRILLIONS CU. FT. ) PROSPECTIVE SPECULATIVE PROSPECTIVE SPECULATIVE LOUISIANA-TEXAS 2.0 2.0 - 4.0 25.0 25.0- 50.0 SO. CALIFORNIA 0.5 4.0 - I0.0 1.0 2.0- 10.0 COOK INLET 0.5 1.0- 2.0 1.0 5.0- 10.0 BRISTOL BAY - 0- 1.0 - O- 5.0 GULF OF ALASKA -- 3:0 - 0- 10.0 OREGON-WASH. - 0- 2.0 - O- 10.0 NO. CALIFORNIA - 0- 2.0 - O- 10.0 FLORIDA SHELVES - 0.5 - 1.0 - 1.0- 3.0 ATLANTIC SEABOARD - 0- 1.0 - O- 5.0 TOTAL 3.0 7.5 -26.0 27.0 33.0-113.0 FIG. 5 - UNDEVELOPED AND UNFOUND PETROLEUM RESERVES OF THE U.S. CONTINENTAL MARGINS. Figure 5 123 Most of the known petroleum in the prolific Gulf Coast marine area lies off Louisiana; less than 1% of the proved oil reserves and less than 4% of the known gas reserves lie off Texas. All of the offshore California reserves are along the coast near Los Angeles, where the off shore part of a single giant reservoir holds more than a billion barrels of remaining reserves and has already produced more than 350 million barrels. All of the pro- ducible petroleum in Alaska is in the valley of Cook Inlet, but production has just begun from reservoirs beneath the waters of the Inlet. (Perhaps Cook Inlet should not be included here at all since it is not a shelf geologically or legally. However, it is beset with the same problems of exploration and production as other marine areas.) These offshore regions have already produced about 2 billion barrels of oil and 5-1/2 trillion feet3 of gas and have a proved remaining reserve of more than 3-1/2 billion barrels of petroleum liquids and 22-3/4 trillion feet3 of natural gas (Figure 4). The known petroleum resources of the U. S. continental margins are therefore slightly more than 5-1/2 billion barrels of oil and 28 trillion feetJ of natural gas. This amounts to about 5% of the known U. S. oil and gas resources, indicating that slightly more than 15% of future discoveries will have to be on the continental shelves in order to average out to a minimum figure of 10% of ultimate U. S. reserves as indicated by earlier published estimates discussed above. PETROLEUM RESOURCES REMAINING TO BE DEVELOPED The volume of reserves in undrilled parts of reservoirs is often difficult to estimate, but far more difficult are speculations regarding the recoverable volume of petroleum that has not yet been found; we can only provide here a range of estimates for areas that have not been explored at all (Figure 5). It is possible that another 2 billion barrels of oil will eventu- ally be proven in fields already found in the Gulf of Mexico, and possibly twice this amount will yet be found. Unproved gas may equal that already found and produced, and perhaps twice this remains to be found - gas appears to become more dominant farther from shore. Estimation is more difficult in California where the geology is more variable and where the drilling has been confined close to the shoreline. Probably only a small amount of the petroleum already found has not been proved by drilling - perhaps 1/2 billion barrels of oil and I trillion feet3 of gas. Possibly twice the amount already proved will be found as exploration extends seaward (or about 4 billion barrels), but another Wilmington field cannot be considered as likely. If the isolated basins of this shelf are as prolific as those onshore, we could expect at least 10 billion barrels. These same proportions apply to natural gas, which is normally produced in this area in conjunction with the oil. It is likely that 1/2 billion barrels have already been found be- neath Cook Inlet, and perhaps two to four times this amount is yet to be found. Gas is abundant in this area and it is not unreason- able that a trillion feet3 have already been found, or that 5 to 10 times this amount will eventually be discovered. These three producing regions obviously account for only a very small part of the U. S. continental margins, but the potential of any one of these cannot be projected into unexplored areas. Each of these regions has had a distinct geological history. 124 210 200- FEDERAL MINERAL ROYALTIES TOTAL INCOME TO FEDERAL AND STATE GOVERNMENTS - OVER $ 3,500,000,000 INCLUDING FED. BONUS PAYMENTS 150- OF OVER $ 2,000,000,000 AND ROYALTY OF $ 489,353,000 Q : FROM OFFSHORE LEASES a 100- TOTAL ROYALTY IOI' FROM ALL SOUcRCES 50 -ND /OTHER , 0/1 95 190 195 190 9 1945 1950 1955 1960 1965 FIG. 7- FEDERAL MINERAL ROYALTIES. Figure 7 127 estimates since we know almost nothing of the geology of these areas. It is to be expected, however, that with reasonable in- centives these deeper regions will also be actively explored in the foreseeable future. Other possible changes of the future cannot now be accounted for in these estimates; e.g. radical innovations in technology, changes in the economic balances, modifications of federal administrative policies, etc. PAST MARINE PETROLEUM OPERATIONS As an indication of what will be necessary to develop these po- tential marine resources, let us review briefly what has been required to develop those we already have (Figure 6). Offshore oil was first produced sometime between 1894 and 1899 in the Suimmerland Field, California, through wells drilled from wood wharves or directionally seaward from the beach. The first field to be produced from a man-made island was Belmont in 1953-1956. Several other islands, as well as permanent platforms have now been added to the southern California shelf. Petroleum operations in the Gulf of Mexico began in 1936 in the High Island Field, Texas, and in 1938 in Louisiana's Creole Field. Each of these was an extension of onshore production, and drilling was carried out from wharves, submersible barges in protected waters, or drilled directionally seaward from the shore. The first seismic work beyond sight of land was in 194-4; the first well was drilled beyond sight of land in 1946; and the first offshore pipe- line was completed in 1951. Production has now been established at least 70 miles from shore. Offshore petroleum was discovered in Cook Inlet in 1962, leading to the subsequent discovery of several other fields. These will be produced from fixed platforms specially designed to withstand the tremendous tidal currents throughout the year and the moving ice in the winter. The first production offshore began to flow at the close of last year. A major problem in the orderly development of these marine resources has been the controversy between the federal and state governments concerning jurisdiction and royalties of these areas. The first suit between these governments was filed in 1945, and others fol- lowed in 1948. A start was made in resolving these disputes by passage of the Submerged Lands Act in 1953, but the dispute in California waters has only recently been resolved by a Supreme Court decision and the problem in the Gulf of Mexico remains un- settled. The increase in production after 1953 is apparent in Figure 6. Since that time, the Louisiana shelf has produced about a billion barrels of oil. The interest of the state and federal governments in marine petro- leum production is obvious from Figure 7. The rapidly increasing governmental revenue is indicated by the fact that the federal government has received nearly $1/2 billion from royalties alone since 1953, and that such royalties now account for nearly half the total royalty received by the federal government from the production of all U. S. minerals. The total payments to state and federal governments for bonuses, rents, and royalties from petroleum exploration and production offshore exceeds $3-l/2 billion to date. These payments to government are a significant factor in the economics and feasibility of marine operations. The bonus pay- ments alone have amounted to a third of industry's total cost of offshore operations and more than half of the total exploration 128 The continental shelves of Alaska adjoining the Arctic Ocean and the Bering Sea are very large - about half the total U. S. shelf area. We know very little about the geology of these regions, but the technologic and economic problems would be tremendous for operating in these remote, stormy, and largely ice-covered areas. The southern Bering Sea Shelf appears to offer the most reasonable opportunities, geologically and operationally. It is not impos- sible that this area may eventually yeild a billion barrels of oil and 5 trillion feet3 of natural gas. The shoal areas among the Aleutian Islands do not seem to offer attractive geological conditions, nor does the Pacific margin of the Alaska Peninsula and the southeastern archipelago south of Juneau. The Gulf of Alaska, however, has known seepages of petroleum. Quite a few expensive coastal wells have been drilled here without success, but the large size of this area could make it equivalent in potential to Cook Inlet, eventually yielding perhaps 3 billion barrels of oil and 10 trillion feetD of gas. However, operations would be very expensive and it is possible here, as in all unexplored areas, that there may be no commercial oil accumulations at all. The Washington and Oregon shelves are presently being explored and a few offshore wells have been drilled in the vicinity without apparent success. If petroleum has formed and accumulated in this area, we might expect as much as 2 billion barrels of oil and 10 trillion feet3 of gas. Similar amounts may be found off coastal California, but we cannot reasonably expect to find such large reserves as those known in the southern part of the state. It is possible also that these Pacific areas may largely yield gas instead of oil. The largest part of the Gulf of Mexico has already been discussed. The west and east shelves of Florida, including the deeper Blake Plateau, are entirely distinct geologically from the marine areas off Louisiana and Texas. There is a small amount of petroleum presently being produced onshore in Florida, and although highly speculative it is possible that at least 1/2 billion barrels of oil will be found on the western shelf (including coastal Alabama and Mississippi) and perhaps twice this amount of all of Florida. Gas reserves may range up to a few trillion feet . The Atlantic Seaboard has an apparent geologic history which is difficult to interpret in terms of petroleum potential, but it does not appear to be as attractive as other areas. Perhaps a billion barrels of oil and 5 trillion feet3 of gas might be expected. ULTIMATE PETROLEUM RESOURCES It would seem then that the continental margins of the U. S. may contain unproven and unfound petroleum resources in the range of about 10 to 30 billion barrels of liquids and 60 to 140 trillion feet3 of natural gas (Figure 5). If the 5-1/2 billion barrels and 28 trillion feet3 of proved resources are added to this, the ultimate offshore petroleum potential may range from more than 15 to about 35 billion barrels of petroleum liquids and from nearly 90 to about 170 trillion feet3 of natural gas. For comparison, the total U. S. production for 1965 was 3.3 billion barrels of liquids and 16 trillion feet3 of gas. These estimates should not be interpreted as limits (the actual petroleum ultimately produced could be greater or less), but merely as a range within which present estimates can reasonably be made. The areas beyond the shelf edge have not been incorporated in these 125 250 OFFSHORE ANNUAL PRODUCTION OF PETROLEUM LIQUIDS (MORE THAN 1,916,000,000 BARRELS) THROUGH 1965 o100- 50-| ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 1//16,020,000 BBLS) THROUGH 1932 ,I~//~////-~o-ooo~~ I I I I 1/////////. I I I I I I I 1935 1940 1945 1950 1955 1960 1965 FIG. 6-ANNUAL PRODUCTION OF PETROLEUM LIQUIDS FROM THE U.S. CONTINENTAL MARGINS. ALASKA OFFSHORE DRILLING (TOTAL TO DATE -MORE THAN 8,250 WELLS) 750 - '- ~500 - I- ~~~~~~~~~~'~4J 1940 1945 1950 1955 1960 1965 FIG. 8 - ANNUAL OFFSHORE DRILLING ON U.S. CONTINENTAL SHELVES. costs. It becomes especially stringent when the leases acquired are for a term of only five years. In addition to the petroleum production and direct revenue to the government already mentioned, other economic benefits result from the industry's marine efforts. The petroleum industry now accounts for about 1/8 of the total U. S. sulphur production, much of it from the Gulf Coast, and a federal bonus of $33.7 million was recently paid to develop sulphur deposits off Texas. A new chem- ical plant is to be built in Alaska to utilize the natural gas of that remote area. About 150 mobile drilling vessels of all types are now operating or under construction, valued at $3/4 billion. The economic value of the complex support facilities and specialized service companies associated with these marine efforts has never been estimated. These economic rewards have not come easily or cheaply, however. For example, it has required the drilling of more than 8,250 wells (Figure B), and before long, drilling operations alone in the Gulf of Mexico will be consuming $2 million per day. Advances and innovations in technology are an ever-present need. A fixed platform is now being built for production in 300 feet of water, and already there are probably 50 ocean-floor completions in water deeper than 250 feet. This is especially difficult since the equipment must serve for the life of the field (20-50 years). Core holes have been drilled in several. thousand feet of water, and deep wells have been drilled successfully in more than 600 feet of water. The risks of such operations are high. In the last three years, offshore losses have amounted to at least $56.5 million, including $12 million as a result of hurricane Hilda (1964) and $22 million from Betsy (1965). The total industry in- vestment in marine operations on the continental margins of the U. S. now exceeds $6 billion (Figure 9). FUTURE OF MARINE EXPLORATION AND PRODUCTION Secretary Udall has estimated that we will have to add 83 billion barrels of petroleum liquids and 450 trillion feet3 of natural gas to our proved reserves by 1980 in order to maintain our present reserve/production ratio. This will require an average annual addition of 5.5 billion barrels and 30 trillion feet3, much greater than past average additions. Certainly a large part of these new reserves must come from beneath the waters of the unexplored con- tinental margins. At best, petroleum exploration is an extremely costly and risky business, and the capital needed to find these new resources will far exceed that spent in the last 15 years. Industry will be hard- pressed to provide such capital financing out of proceeds as it has generally done in the past. It will be a major technologic chal- lenge to recover these resources from the deeper waters of the continental margins and immense sums of money will be needed for this gamble. Far more money has already been invested in the oceans by petroleum companies than by all other industries, and it is likely that this will continue to be true in the future. However, there are few barriers - whether natural or technologic - which cannot be overcome given reasonable incentive. Assuming that this incentive is not impared or destroyed, we can look for- ward to an expanding, challenging, and exciting future in the development of the marine petroleum resources of the United States. 130 1,000 OREG. OFFSHORE ALASKA WASH. (TOTAL INDUSTRY INVESTMENT 750 - ABOUT $ 6,000,000 ) '-., I C 500 - 250 - OU/S/ANA 193! -1939 1940 1945 1950 1955 1960 1965 FIG. 9 -INDUSTRY INVESTMENT IN THE U.S. CONTINENTAL MARGINS. REFERENCES Atwater, Gordon I., 1956 - Future of Louisiana offshore oil province: American Association of Petroleum Geologists Bulletin, Vol. 40, No. 11, p. 2624-2634. Averitt, Paul, 1961 - Coal reserves of the United States: U. S. Geological Survey Bulletin 1136, p. 100. Carmical, J. H., 1955 - New York Times, August 7, 1955. Egloff, G., 1952 - Oil and gas as industrial raw materials: Re- sources for Freedom, Vol. IV, Report of the President's Materials Policy Committee, U. S. Government Printing Office, Washington, D. C., 193 p. Hendricks, T. A., 1965 - Resources of oil, gas, and natural gas liquids in the United States and the world: U. S. Geological Survey Circular 522, 20 p. Hubbert, M. King, 1956 - Nuclear energy and the fossil fuels: Drilling and Production Practice, American Petroleum Institute, p. 18. Hubbert, M. King, 1962 - Energy resources, a report to the Com- mittee on Natural Resources of the NAS-NRC: National Academy of Sciences Pub. 1000-D, p. 22-90. Hubbert, M. King, 1965 - National Academy of Sciences report on energy resources; Reply: American Association of Petroleum Geologists Bulletin, Vol. 49, No. 10, p. 1720-1727. Johnston, J. E., J. Trumbull, G. P. Eaton, 1959 - The petroleum potential of the emerged and submerged Atlantic coastal plains of the United States: Fifth World Petroleum Congress, Section I, paper 22, 8 p. Kastrop, J. E., 1955 - Louisiana's offshore picture: The Petroleum Engineer, Vol. 27, No. 13, p. B-40. Netschert, Bruce C., 1958 - The future supply of oil and gas: Johns Hopkins Press for Resources for the Future, Inc., Baltimore, 134 p. Pratt, Wallace E., 1947 - Petroleum on continental shelves: Amer- ican Association of Petroleum Geologists Bulletin, Vol. 31, No. 4, p. 657-672. Rubel, A. C., 1966 - Freedom is key to west coast supply: Oil and Gas Journal, February 28, 1966, p. 50-51. Schultz, P. R., 1952 - What is the future of petroleum discovery?: Oil and Gas Journal, July 28, 1952, p. 259. Shurr, Sam H. and Bruce C. Netschert, 1960 - Energy in the Amer- ican economy 1650-1975: Johns Hopkins Press for Resources for the Future, Inc., Baltimore, 774 p. Terry, L. F., 1950 - The future supply of natural gas: Proceedings of American Gas Association, 1950, p. 155-159. 132 U. S. Geological Survey, 1951 - Fuel reserves of the United States: Senate Committee on Interior and Insular Affairs, 82nd. Congress, 1st. Session, U. S. Government Printing Office, p. 32. U. S. Geological Survey, 1954 - Estimated potential crude oil and natural gas reserves of the continental shelf: in Petroleum Facts and Figures, American Petroleum Institute, New YErk, p. 120. Weeks, L. G., 1950 - Discussion of estimates of undiscovered petroleum reserves by A. I. Levorsen: Proc. United Nations Scien- tific Conference on the Conservation and Utilization of Resources, 1949, Lake Success, New York, p. 107-110. Weeks, L. G., 1965 - World offshore petroleum resources: American Association of Petroleum Geologists Bulletin, Vol. 49, No. 10, p. 1680-1693. Exploration Engineering and Instrumentation Problems in the Marine Environment B. W. Davis Abstract The fluid dynamics of towed bodies is considerably more complex than that of free falling bodies. Besides the normal drag, turbulence and separation effects common to free falling bodies, the towing device acts as a random forcing function. The forc- ing function will often have both periodic and non-periodic components superimposed on the natural effects produced by the fluid on the towed body. The fluid mechanics becomes further complicated if the towed body itself is complex. An example of a complex towed body is a .,neutrally buoyant" streamer used in marine exploration for pet- roleum. its length is often greater than 1-1/2 miles and its mass greater than seven tons. The fluid drag induces an approxi- mately linearly decreasing tension which varies with speed from several thousand pounds at the front to a negligible amount at the tail of the streamer. The tow depth of the streamer will vary as its buoyancy changes with variation in temperature and salinity of the water. These factors are all critical to per- formance and to reliability of seismic data collection. Three different innovations in streamer design have resulted in significant improvement in performance and reliability. A system for automatically ballasting the streamer while it is under tow was developed during 1965. With this system, accurate control of the streamer depth can be maintained electronically from the towing vessel. A recently developed acceleration can- celling hydrophone has provided significant gains in sensitivity and signal to noise ratio. Modular streamer construction pro- vides rapid section decoupling and improvement in connector reliability. INTRODUCTION A marine seismic streamer is a flexible tube which houses an array of acoustical sensors, usually piezoelectric or magneto- strictive elements. The tube is filled with a light-weight liq- uid to provide buoyancy and acoustic coupling to the sensors. It is usually towed behind a ship at a constant speed. In petroleum exploration, continuous tow speed of streamers nor- mally is 5-7 knots at a water depth of 30-50 feet. The drag induced tension on the towed body is taken up by one or more wire ropes running through the streamer. The diameter of the streamer is fixed by balancing the negative buoyancy of the solid members of the streamer with the positive buoyancy of the liquid inside the streamer. Streamer length will vary from a few hundred feet to 8,400 feet, depending on the seismic energy source being used and the survey area. Typically, 24 channels of seismic data are recorded from 24 active sensor groups having 134 tan or twenty hydrophones in each group (Figure 1). The simpli- fied order of progression of processing seismic data starting with the sensor signals and ending with the structural maps 4s illustrated in Figure 2. FACTORS AFFECTING PERFORMANCE AND RELIABILITY Criteria used for measuring performance of seismic data acquisi- tion equipment is signal/noise ratio. The SIN and sensitivity of the hydrophone determine the dynamic range of the data collection system. Surface reflections from the water-air inter- face also make tow depth of the sensor array an important factor in performance. There are many sources of noise, but the pre- dominant contributors are mechanically induced by the towing vessel and by the fluid through which the streamer is towed. Mechanical loading from fluid drag, cyclic stresses and environ- mental conditions control the reliability of a marine streamer. Fatigue failure of stress members, fatigue of signal wires at connector terminals, salt water intrusion and corrosion are factors which have limited reliability of marine streamers. Re- search efforts in defining the problems and development engineer- ing have resulted in significant advances in performance and reliability of seismic data acquisition equipment in a marine environment. MECHANICALLY INDUCED NOISE Mechanically induced noise occurs when a hydrophone group is caused to move transversely from its nominally horizontal posi- tion and when it is accelerated longitudinally. Mechanical vibrations are introduced to the streamer from the tugging action of the boat and the strumming of the highly stressed lead-in. The strumming is forced from vibration of the towing vessel and fluid acting on the lead-in as it cuts laterally through the water. Extremely minute vertical displacements will generate large noise signals as a result of variation in the hydrostatic head. Acceleration forces associated with a likewise small displacement of the hydrophone create a sufficient strain in the crystal to also generate significant noise signals. It is the transverse vibrations which produce large noise signals. If a single hydrophone is forced to vibrate sinusoidally in a plane at right angles to the streamer with one degree of freedom, its motion can be expressed by: X = -A sin Wt x = -Aw cos 4it x = AW2 sin cut where x, A, w~ , and t are, respectively, displacement in inches, amplitude in inches, angular speed in radians/second, time in seconds. it is noted that acceleration is 1800 out of phase with displacement. However, assuming the hydrophone is directly fluid coupled to the forcing function, both positive and negative accel- eration will generate a compressive hoop stress in the crystal. if the hydrophone is polarized so that a compressive stress gen- erates a positive voltage then the voltage output, ea (t), would be described by: ea Ct) 8 *s(t) + fIt,1 135 j ~- w/00 10 IHYDROPtONES (TYPICAL STREAMER SECTION) MARKER HYDRODYNAMIC DEPRESSOR TREAMER (24 DATA CHANNELS) LEAD-IN TYPICAL TOW CONFIGURATION OF A MARINE SEISMIC STREAMER FIGURE 1 SEISMIC SENSOR ARRAY REFLECTED AMPLIFIER DIGITAL DATA ~SUB-SURFACE bpSIGNALS RECORDING PROCESSING SRCUA SYSTEM CENTER !MAPS PLAYBACK MONITOR SEISMIC ENERGY SOURCE FOR QA SIMPLIFIED FLOW OF SEISMIC DATA FIGURE 2 where: 2 E = crystal stress sensitivity (volts/lb/in2) As(t) = time varying change in stress (lbs/in2) = m A 2 sin wt Ax = cross sectional area of crystal (in ) m = mass of crystal Therefore, ea(t) = AW eas m = A2 sin W t + f(t, ) The function, f(t,T), is present in the acceleration noise equation because of the discharging nature of the crystal. From a static condition, a crystal will generate both a positive and negative voltage from application of only positive pressure if the period of the induced pressure is longer than the time con- stant,or, of the crystal discharge. This is illustrated in Figure 3. 4-I v - applied X ) ~ / pressure o 1~~~~~~~~~~~~~~44 0 0 0 g / time /O/ /crystal response FIGURE 3 However, if it is assumed that: 1 f(t,T ) can be neglected and the acceleration noise voltage reduces to: ea(t) = m AW2 sin w t ea~t = s A x The pressure sensitivity, p (microvolts/microbar), is related to stress sensitivity by: P 138 A_ Es = 0.068 A . p f where, Af = projected area of the crystal normal to its longitudinal axis (in2) Therefore, ea(t) in terms of pressure sensitivity is: (1) ea(t) = 0.068 p m(A2 sin t) . 106 micro- f volts The noise in microvolts generated by change in hydrostatic head, eh(t), is given directly by: eht) = .0.068(A sin X.t)(0.44) 106 eh(t) = Cp' 12 1 A sin Wt 16 (~~~~~~~~~~ ~2) (2) eh(t) = Ap i 400t .10 The predominant noise energy is in the 5-15 cps band when towing at 5-7 knots. In this band, the acceleration generated noise is somewhat greater than the noise generated by variation in the hydrostatic head For example, at 5 cps and a displacement amplitude of 10-a inch, acceleration noise is: 0.068 p mA2 106 = 29 microvolts for a hydrophone with a sensitivity of 15.4 microvolts/microbar and a projected area of 1.5 in2. The corresponding noise generat- ed by variation in hydrostatic head would have an amplitude of: p . TR . 106 = 3.85 microvolts As the frequency increases, it can be seen from equations (1) and (2) that the acceleration noise will be dominant over the noise generated by hydrostatic head change. ACCELERATION-CANCELLING/DISPLACEMENT-IMPEDED HYDROPHONE Small hydrophones can be built and suspended in a streamer in such a way that it is essentially isolated from the transverse vibration of the streamer. By doing so, a significant reduction in noise can be achieved without sacrificing sensitivity of the hydrophone. If a round tubular hydrophone is suspended in the streamer according to the schematic illustrated in Figure 4, where the forcing function is coupled through a spring to the center of the hydrophone, the amplitude of transverse vibration of the hydrophone can be reduced. The forcing function acting through the spring on the center of the hydrophone will tend to cancel acceleration generated noise because the bending will result in compression on one half of the 139 tube and expansion in the opposite half. This is exaggerated schematically in Figure 5. However, it will not be completely acceleration noise cancelling because the acceleration force will tend to superimpose an overall compressive stress on the bending stress. W11 ~ - u(t) hdrophone FIGURE 4 compression tens ion FIGURE 5 140 In an effort to predict the behaviour of the hydrophone isola- tion system, a simplified mathematical model was utilized. As further data on the nature of the inputs to the streamer are available, a more extensive and thorough mathematical model may be necessary to predict system response. The one dimensional model is shown schematically in Figure 6; ke represents the spring constant for an equivalent linear spring; ce is the equivalent viscous damping coefficient; m is the mass of the suspension. The system input is denoted by u(t), applied displacement to the streamer, and the response by x(t), displacement of the hydrophone. k e Ce c a ~.//////, - tu(t) FIGURE 6 If it is assumed that u(t) can be represented by: (*) u(t) = uo sin W t where, uo = maximum displacement from equilibrium; W= the circular frequency, then the steady-state response is given by: (**) x(t) = A sin (ft -i ) 0 o where, 1 + (2�r 4"/n) 1/2 A = (1 _2/ n2)2 + (2� A/n)2 (*) This input is assumed for illustration purposes. (**) Harris, C. M., and Crede, C. E., "Shock and Vibration Handbook", Vol. 1, Mc-Graw-Hill, New York, 1961, pp 2-14. 141 FIGURE 7 MOTION TRANSMISSIBILITY RIGIDLY-MOUNTED HYDROPHONE &ELASTICALLY-SUSPENDED HYDROPHONE i +4 ---4-- + 6 o~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.o...... 2.5~~~~~~~~~~~ 0.15 2 determined - from power 1.5 . . ~~~~~~~~spectra data 4.) t IA 2.5. (5 0 2 . ~~~~~~~~~14 = arc tan 2r (C/,.n)3 I -W2Aon2 + 4r 22/Wn2 A = motion transmissibility = phase angle = Ce fraction of critical damping C C CLWn = undamped natural circular frequency The motion transmissibility, A, is shown in Figure 7 as a function of CJ/Wn' The experimental points shown in Figure 7 show a comparison of the motion transmissibility between a rigidly-mounted hydrophone and an elastically-suspended one. Constants used in making the comparison are: ~n~~~~T L~n = i = 188 rad/sec = 30 cps The ratio x/uo was evaluated at each frequency from power spectra; x from the elastically-mounted hydrophone spectrum and uo from the rigidly-mounted hydrophone spectrum. Average power over the complete spectrum was the same for each hydrophone. Two conclusions may be drawn from this simplified analysis: The suspension is lightly damped - approximately 10% critical damping. Better lower frequency (less than 50 cps) response is attainable by lowering the suspension's natural frequency. The power spectra shown in Figure 8 illustrates the improvement gained from a spring suspension hydrophone system. The power spectra curve identified as "No. 21" was from a rigidly-mounted hydrophone and power spectra curve "No. 22" was from a spring suspended system with a 30 cps natural frequency. AUTOMATIC STREAMER BALLASTING Maintaining proper depth of long streamers is generally very difficult because of change in density Of sea water as a result of the variation in salinity and temperature of the sea water. The ocean is a dynamic mixture of liquid and solids. Its dyna- mics cannot be explicitly defined for a small area. Currents, salinity, temperature and density normally will not be constant for any given area throughout a 24-hour period. This is es- pecially true for relatively shallow water near shore line with streams where it is often desirable to collect marine geophysical data. 143 -622 -12 . -24 -30 - -36 - , -42 - 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 frequency, cps TOW NOISE POWER SPECTRA (BOAT SPEED 6-7 KNOTS) FIGURE 8 Proper streamer depth will enhance signal response. Seismic reflections from the air-water interface in the seismic band will reinforce the primary reflection if the streamer depth is properly maintained. A streamer towed near the surface will have considerable noise introduced from surface turbulence. The danger of damaging a streamer is always present, if it is towed near the bottom. STREAMER RESPONSE TO A WATER DENSITY CHANGE It is not uncommon for the density of sea water to change 0.1 lb/ft3 while moving through a distance of three miles in an area within 5-10 miles of a shore line. For a 7,000 foot long by 2.5 inch diameter streamer weighing 7.5 tons, this would in- duce an unbalanced force of 24 lbs., enough to cause a 50-60 foot change in towing depth. The rate of change of depth is governed by the equation: pv2 F = CDAs 2 where, CD drag coefficient A = projected area of streamer (ft2 P = density of sea water (slugs/ft3 V = velocity (ft/sec) F = unbalanced buoyant force (lbs) The unbalanced buoyant force changes with time, however. If it is assumed that the 24 pounds buoyancy change occurred at a linear rate in three miles when the ship's speed was 650 ft/ minute, and if the drag coefficient is assumed to be constant at 1.2, the rate of change in streamer depth during this interval is given by: (3) V(t) = 60 Q F ) 1/2 ft/min = 1.44 tl/2 ft/min Therefore, the streamer would be expected to change in depth, S, according to the integral: S = 1.44 St tl/2dt Evaluating the integral between the limits of 0-10 indicates the streamer depth would change about 30 feet during the first 10 minutes. The ideal situation is to be able to control the streamer depth by having the capability of changing its buoyancy from the boat while it is still under tow. An electromechanical system to serve this purpose was developed whereby the buoyancy of sever- al streamer sections can be changed continuously by varying the displacable volume of the sections. Each section can be con- trolled independently. The variable buoyancy sections are spaced a few hundred feet apart throughout the length of the 145 streamer. Each section is capable of varying the buoyancy by 45-50 pounds in approximately 10 minutes. The length of the streamer determines the number of ballasting sections required. To have complete depth control, the ballast system was designed to produce a streamer depth response time rate greater than the maximum time rate expected for a maximum change in ocean con- ditions. Response rate can Le determined from equation (3). I0 2.F 1/2 V(t) = 60(--)1/ ft/min If five ballast sections are employed in the 7,000 foot streamer described above, the buoyancy can be altered at a rate of 25 lbs/ minute. Theoretically, the streamer depth could be changed according to the integral: S = 7.2 t /2dt Evaluating the integral betweeft the limits 0-10 minutes, S = 7.2 t1/2 dt shows that the depth could be changed approximately 150 feet in 10 minutes. However, in practice this is not possible because of the streaming characteristics of a long flexible towed body. Practically, the depth can be altered at a sufficient rate to compensate for the most extreme water density variations in the Gulf of Mexico. ACKNOWLEDGEMENTS I would like to acknowledge the help of Dr. Roy Johnston in preparing this paper and particularly for his analysis of the hydrophone isolation system. I am also indebted to the Science Services Division of Texas Instruments, Incorporated for permitting me to publish this paper. 146 POSITION DETERMINATION UNDER THE SEA Kenneth V. Mvackenzie U. S. Navy Electronics Laboratory San Diego, California 92152 Abstract Accurate position determination by a manned submersible in deep water is important when a controlled search of a bottom area is required to make certain scientific studies or to locate some specific object. The visibility is limited by the turbidity of the water and the power of the flood lights. Visibility of 20 feet is considered good at the ocean bottom; to insure successful operations the accumulated error of the navigation system should be less than 20 feet over eight hours of operation. Several navigational methods are discussed covering the range from the very simple aids to the more sophisticated equipments. Acoustic methods are the best at present but generally not entirely satisfactory. The state of the art is advancing and the situation should improve rapidly. The searches for USS THRESHER by TRIESTE in 1963 and TRIESTE II in 1964, since they were actual operational assignments rather than ex- perimental or purely research dives, contributed to a fuller understand- ing of the major problems of navigation by manned submersibles in deep water. These problems, in varying degrees, exist in any diving operation. Several approaches have been studied in an attempt to develop self- contained navigation aids which could feasibly be installed aboard manned submersibles to improve the accuracy and speed of their operations and to some extent reduce the almost overwhelming obstacles they encounter in the deep underwater environment'. The following sections will sum- marize and briefly discuss both the problems and the attempts which are being made to solve them. In some cases, details of the THRESHER operations are included as a useful frame of reference. Escort surface craft for locating the dive site, and acoustic tracking sys- tems, are of course vital in initiating and supporting a dive operation. However, the concern in this paper is primarily with devices and instru- ments on the submersibles themselves, rather than with aids which are external to the craft. In developing navigational aids for submersibles, any approach must first take into account the inherent constraints of the craft itself. Equipment aboard submersibles must be able to operate accurately at temperatures from 300F to 110F, and withstand immersion in salt water without dam- age from corrosion. Inside the sphere, equipments and devices must maintain their reliability and accuracy in a high-humidity environment. Maneuverability or safety of the craft must never be impaired. Small manned submersibles present further problems, as their space, total payload, and available power are limited; extra batteries or inverters must count as part of their payload, since somd equipments require power which would not be adequately supplied by available dc batteries or ac power supply The opinions and assertions contained here- in are the private ones of the writer, and are not to be construed as official, or as reflecting the views of the Navy Department or the naval service at large. 147 The external sensors and wiring must withstand high pressures of thous- ands of pounds per square inch. Equipments must be actually pressure- tested, because some equipments built according to valid theoretical designs have failed in the pressure chamber. For a safety factor of at least two, a good rule is to test each equipment for 24 hours at apressure in pounds per square inch numerically equal to the maximum operating depth of the vehicle in feet. For example, if the submersible is certified for 6000 feet, the 24-hour pressure test should have a pressure of 6000 psi or greater. OPERATIONAL REQUIREMENTS Underwater, limited visibility presents severe operational problems. Be- low 1000 feet the sea is in complete darkness, so visibility is possible only from the flood lights carried on the craft. Depending on the turbidity of the water and the power of the lights, visibility can range from zero to 30 feet or more. Aboard the bathyscaph the observer could usually see 80 to 100 feet ahead when she was running very close to the bottom. When 30 to 40 feet from the bottom, the details on the bottom became very in- distinct. This indicates that the transparency of the water on the bottom at 10 or 15 feet may be greater than in the water further above the bottom The practical effect is to limit how far above the bottom one can run and still distinguish the details necessary to accomplish a mission. Dead-reckoning navigation was not sufficiently accurate for the THRESHER search. An aircraft gyro gave the headings to one degree but the bottom currents were variable in direction and ranged in magnitude from zero to one knot. Consequently, the set of the craft was not constant. Locating reference "landmarks" is not easy. In the THRESHER search during 1963 sometimes as much as two hours elapsed between sightings of the plastic reference markers that will be discussed later. The unknown sets and limited visibility impose a practical navigation requirement for no more than 20 feet of accumulated error over eight hours of operation. Manned submersibles need good sonar obstacle-avoidance equipment to give warning in sufficient time to avoid a disastrous collision. Operating areas have practically never been adequately mapped. One of the first operational requirements is to get good bathymetry to define the opera- ting terrain. Rough terrain is often encountered. In the THRESHER area at depths of 8000 to 8500 feet, there are slopes of 150 with occasional rocks as big as automobiles. Figure 1 illustrates the bottom bathymetry in the THRESHER area. Con- tours of the hills and valleys are shown only superficially; obviously, an echo-sounder obtaining data two miles above the area with a 300 beam cannot define the bottom in detail. The heavy lines in Fig. 1 were ob- tained2 from an interpretation of side-looking sonar records obtained from a "fish" towed 200 feet from the bottom. Fig. 2 is a composite of some of the records from which interpretations were derived. These particular records have a resolution of six feet in both directions. The sweep is from the center out and the records show a bottom width of 1200 feet to each side of the "fish." Higher resolution could be obtained with a different mode of operation such as towing the fish 20 feet above the bottom. Of course, towing over an unknown bottom presents prob- lems and very likely the equipment would get hung up onthefirst available 148 cliff or upslope. However, when closer to the bottom, the resolution can be less than a foot in both directions but the coverage only 200 feet to each side of center. A search may be directed to a small object, as in the case of the bomb recovery off Spain, or involve a wider area as required by the THRESHER operation. In either case, navigation must be sufficiently accurate to direct the submersible to within sighting distance of the point of interest. NAVIGATIONAL METHODS Several navigation methods are feasible but equipments should be made small, lightweight, and trustworthy to be of use for the small manned submersible. At first it might seem logical that during a series of dives a familiarity with the bottom would be developed and could assist in navigation. It is true that some gross features are recognizable and broad types of features and rocks become familiar, but identification of particular ones is very uncertain. As an analogy, consider an observer placed at random in an almost featureless rolling desert on a moonless night, with a flashlight allowing him to see about 30 to 40 feet. He is allowed to walk (a speed which would be "fast" for a manned submersible while observing) and examine the terrain for a period of six hours. Next night or a week later he might be placed at random initially at some other spot as far as 1000 yards away, in a 20-knot wind (which might approximately parallel the disturbing effect of bottom current for the submersible). Somehow he would be supposed to store the hours of information for immediate re- trieval. Of course, the analogy would be even better for a scuba diver with a powerful search light, diving on a moonless night on some available guyot in the Pacific. SIMPLE METHODS The usual aircraft gyro is adaptable to the small manned submersible. The gyro can be turned on before the dive. After it has stabilized it can be gated at the correct bearing furnished by the gyro of the escort ship and can then be used throughout the dive to obtain the headings to the nearest degree. Magnetic and fluxgate compasses can be utilized. The magnetic variation or declination must be known for the area, as well as the deviations for all headings. The compass can be compensated to minimize the deviation with heading. In addition, there will be local and unknown anomalies at the bottom which are well known to the land surveyor who sometimes uses a compass for bearings. (He guards against error by taking forward and reciprocal bearings from each occupied point of a traverse. ) Some device to accurately measure the actual motion over the bottom is required to obtain dead-reckoning navigation. Since submersibles gener- ally operate at low speeds, the set of the current is an important factor in navigation. The direction and magnitude of the current can be estim- ated by observing the bottom while allowing the craft to drift with the current. This estimate can be utilized with the measured water speed and heading while underway. Unfortunately, even a good estimate is not 149 reliable, because time and terrain cause the currents to vary in both mag- nitude and direction. Dead-reckoning navigation definitely requires some device to accurately measure the actual motion of the craft over the bottom. Speed relative to the bottom can be obtained by trailing a wheel on the end of a trolley attached to the underside of the submersible. Some tests aboard the Perry Cubmarine are reported by W. E.. Hart and R.F. Busby'. Their readout was an odometer. A small computer could combine headings and speed of advance to give a DR plot automatically. During the 1963 THRESHER operations, one method which proved success- ful utilized a grid of plastic reference markers, laid a little over 58 feet apart and numbered from #1 at the south end to #131 at the north end. Each line of markers was approximately 750 feet apart in the east-west direc- tion. Developed by the Hudson Laboratories, these markers consisted of colored plastic sheets, 17" x 21", each with an identifying letter and serial number painted on both sides. They were rolled and tied to 10-pound sash weights and dropped from the surface ship. The ship proceeded for the laying operation by using Decca purple and green lines to control the track. After all navigation data were reduced, Fig. 3 was prepared. It can be seen that neither the spacing nor the track is constant at the surface, and, of course, since each one took about an hour to reach the bottom, the effect of the variable and uncertain currents would be to distort the actual location on the bottom considerably from Fig. 3. However, these "fortune cookies" (so designated because they had to be unrolled before the message could be read -- and many of them failed to unroll) proved extremely use- ful in the THRESHER search to identify different sections of the THRESHER in terms of this grid line. A second set of plastic markers was laid for the 1964 operations because the fortune-cookie sightings were often too widely spaced in time. Both sets of plastic markers and debris showed up in the photographs obtained by cameras towed by surface Ships in both 1963 and 1964 and resulting information was valuable in planning the oper- ations of the TRIESTE and TRIESTE II. Some similar type of bottom marking might be advisable for other search problems. INERTIAL NAVIGATION Inertial navigation is progressing rapidly. The author knows of no system that is light enough for small submersibles and still has an accumulated error less than 20 feet over eight hours of operation. Systems are being developed that are becoming lighter and more accurate and perhaps these will be available in the near future. A reliable system would be valuable when the submersible is operating in very deep water far from both the surface and from the ocean's bottom. OPTICAL BEACONS Another navigation method that might be used is optical. A bright flash- ing strobe light might be seen 500 yards or more and serve as a beacon on the bottom. Flashes were observed at the surface at night in 1952 when strobe flash pictures were taken at a depth of 1500 feet for scatter- ing layer studies. Research is being done at the Navy Electronics 150 Laboratory to measure the actual light-scattering and absorption proper- ties in the water column at the bottom. Results of this study will permit an assessment of the value of such a light as an aid in position-fixing as well as the optimum placement of flood lights aboard the craft for direct observations. ACOUSTIC METHODS Acoustic methods offer the most hope for good navigation at the present time. There are several types. One type involves three receivers aboard a surface ship, receiving signals from the submersible. Such a system was used successfully in 1962 at Japan when the MARCEL LE BIHAN tracked the French bathyscaph ARCHIMEDE. A second type of system is the more sophisticated 3-D acoustic tracking system developed by the University of Washington Applied Physics Laboratory, to track their unmanned research vehicle. The sur- face ship queries and receives replies from the transponder. It utilizes travel-time differences to three receiving hydrophones and applies correc- tions for roll, pitch, and yaw to compute the relative coordinates of the transponder to the ship. This method was adapted for use on surface ships for the THRESHER operations in 1963 and 1964. Fixed transponders were moored on the bottom and a mobile transponder installed on the submers- ible. The computer aboard the USNS MIZAR in 1964 automatically deter- mined the coordinates of the TRIESTE relative to the bottomed transponder and relayed this information back to the bathyscaph by underwater sound telephone system. It would not be feasible to have the 3-D receiving system on the submers- ible because the spacings between the three hydrophones would be too small for any precision. However, an adaptation is possible where the submersible queries two or more transponders simultaneously and then computes its relative position by travel-time differences. A small com- puter would be feasible for this job. PROBLEMS OF LAYING TRANSPONDERS OR BEACONS It sounds simple to place transponders or pingers on the bottom; but, in fact, it is very difficult to obtain any precision. A transponder string with an anchor and a buoy to support the transponders and/or pingers can be dropped from the surface ship as accurately as possible. This would give a reference point on the sea bottom from which submersible sonar equip- ment could determine bearing and direction. A second string dropped at another desirable point and distance from the first could establish a "line" for both submersible equipment and surface ships' sonar to triangulate on. Of course, even if the surface position of each drop is known to an accur- acy within 1000 feet, each string may take an hour or more to reach the bottom and may be moved considerably by currents (generally unknown). The result, then, would be two or three reference strings on the bottom, with neithertheir separation distances nor the relative bearings known with certainty. The transponders can be queried by the surface ships with precision electronic position-fixing equipment and their relative position determined from many measurements. The strings may take as much as three hours to reach the bottom in very deep water, but, ideally, the currents will be very small for most of the downward journey. The ships 151 may be at sea a thousand miles or more from land and any available elec- tromagnetic navigation aids may have absolute errors of a half a mile or more. This problem could be alleviated by having three surface ships keep position on each other as accurately as possible, and simultaneously drop three reference strings with the desired geometry. Operations could then be conducted relative to the transponder strings. The transponders and/or pingers should work with both the surface vessels and the submers- ible for successful operations. SOME UNDERWATER ACOUSTICS All transponders or pingers at the bottom will operate with the limitations imposed upon them by the physics of the problem. One of the problems to consider is how far to buoy the transponder or pinger above the bottom. Sound speed increases with pressure approximately 1.8 feet per second for every 100 feet of depth. This causes upward refraction that curves the sound beam upward and creates a shadow zone near the bottom, at ranges beyond that where the limiting ray becomes tangent to the bottom. No signals from pingers or transponders can be received if the receiver of the submersible is in the shadow zone nor can sound from the submers- ible be received by the transponder. The higher the transponder or the submersible from the bottom, the greater the operating range. Generally, the submersible will operate within 15 feet of the bottom and the trans- ponder can be buoyed to ride, say, 200 feet above the bottom. This gives a maximum possible usable range of 4400 yards. However, the beam patterns of the equipments must be considered. The vertical angle in- creases as the range decreases, and the vertical directivity of the submersible receiver can result in no signals being detected over self noise for all ranges less than some minimum useful range. The blankout range will be smaller, the closer the transponder is to the bottom. On the other hand, if the transponder is too close to the bottom, it may have landed in a depression and become shielded and thus of no use to the bottomed submersible. Bottom topography information is necessary to make the best choice of distance above the bottom. It is not always true that refraction will cause a shadow zone, because in some areas the steep thermal gradient near the bottom will cause strong downward refraction. Some of these gradients have been reported by R. Gerard, et a13, for the Atlantic. So, in the design of the best trans- ponder string we must include the requirement of good oceanographic information for the last 300 feet of depth. Even when the submersible is operating near the bottom with a near-bottom pinger or transponder at a range where direct rays can arrive, difficulty may be encountered due to interference phenomena. The grazing angles of incidence will frequently be less than the critical angle and the acoustic pressure field will exhibit interference phenomena due to the combining of three kinds of rays. For grazing angles less than critical, there will be a direct ray, a bottom-reflected ray (with a change in phase at reflection that can approach 1800), and a ray that has been partially propagated along the boundary. For grazing angles greater than critical only the direct and bottom-reflected need be considered. The change of phase on reflection may be near zero or 1800depending on the type of bottom. 152 The actual effective sound speed at the bottom needs to be known for any precise navigation. Anomalies may exist. Research is underway to determine the best in-situ sound-speed equation at high pressures and to then determine any sound-speed anomalies and their causes. Bottom reverberation can be a severe limiting factor in many cases. Measurements will be made of in situ bottom reverberation near grazing angles of incidence. A great deal of information is available near graz- ing angles in shallower waters over a large frequency range. If a search is to be made for small objects of small target strength, reverberation in some areas may mas the echo. Some areas have rocks and pebbles; some have manganese nodules scattered about. Other areas have a rough terrain and show many confusing, unwanted echoes. Optimistically, this is not all bad because some of these may serve as acoustic landmarks and definitely aid the navigation problem. DIRECT RANGE AND BEARING FROM TRANSPONDERS OR PINGERS Transponders may be queried by continuous-sweep FM sonar aboard the submersible. Each transponder will show on the screen as a blob, which will be wider than a 3-dB-down beam width and more extended in length than the range increment of each of the filters. This is necessarily so because the total range will, in general, be broken into only 40 to 60 incre- ments and then there will be some response by adjacent filters. To get sharp beams generally requires high frequencies and this limits the range. The frequencies used range between 30 and 100 kc/s. The operating freq- uency design choice depends on what trade-offs one wants to make for sharpness of detail and range of operation. A simple ping sonar can be used with a transponder. The time on the ping sonar can be measured quite accurately, which means the range can be fairly accurate if the sound speed is known. The azimuth uncertainty will be extended over 5 to 10 degrees or more because of the beam width of the receiver. A system that will be used by the Navy Electronics Laboratory will trans- mit an omnidirectional ping. Transponders will respond at slightly different frequencies. The transponded signals will be received by an omnidirectional receiver and the ranges displayed on a recorder. Travel times can be determined to use for computing relative position. In addition, a lightweight receiver in a corner reflector will be utilized to determine the bearing of any one of the transponders with an accuracy of 5 degrees. ACOUSTIC .DOPPLER NAVIGATION One very promising method is an acoustic bottom doppler navigation sys- tem. This can work well when the manned submersible is operating near the bottom but would probably vehicle-noise limited at mid-depths. At present, available equipments are not yet light enough for the very low payload of smaller manned submersibles as, for example, ALVIN, ASHERAH, and DEEPSTAR DS-4000. Bottom doppler navigational equip- ments similar to those developed by Raytheon or Loral Company will, I am sure, be utilized in the future. Such a system could operate with an 153 inertial navigation system, and could be updated by use of any transponder information, bottom reference points, or plastic markers. CONCLUSIONS The state of the art has developed rapidly and we are on the threshold of reliabld bottom navigation by manned submersibles. We have come a long way since the first operational job with the THRESHER search only three years ago. It is significant that all methods of navigation must be exploited to successfully accomplish missions of the deep manned submersible. References Proceedings of the ION National Marine Navigation Meeting, Manned Deep Submergence Vehicles, January 1966. (in press) a C. S. Clay, J. Ess, and I. Weisman, "Lateral echo-sounding of the ocean bottom on the continental rise", Sour. Geophysical Research, v. 69, pp 3823-3835, September 1964. 3 R. Gerard, M. Langseth, and M. Ewing, "Thermal gradient measure- ments in the water and bottom sediment of the western Atlantic", Jour. Geophysical Research, v. 67, pp 785-803, February 1962. 154 440 (T ' , 2410t4 5 rll r .~~~~~~~~~~~~-~'4 --' j ' --41143 o ~ ~ ~ I- 'fi 2470 i T� 45 ' 4 \�1~~~ --4�' I � , Go xi 2500 - -4144�i : THRESHER SEARCH . . . C TTOE BOTTOM FEATURES IN FORTUNE COOKIE AREA ZO '.TERZ ZO~R TES'l RECORDED BY SIDE-LOOKING SONAR Fig. 1. Bottom features in fortune-cookie area (Fig. 7, ref. 2). 155 CD 01 ~ ~~ 0 0 � '~ ',~~~~~~31 .r- 12 ~ 4 131 12 -3 3 -. 0 , L 2 o D -12 I1 12 106 115~~12G 4a 10 9 I -J 9 0 ' 4 -8 954 7 131 10 I33 122 13~ ~ ~~~~~~~~~~~~~17 12 *1247 14 121 i 9 112 16'1 ilB 104 ,i I ir9 ' Il 64 1029 110 ~ �I 985 8 11 ~ ~ ~ ~ ~.9 e l 04 ~~~~~~~78 66 ~ ~ 6 669 67 44968 661 t 31 43i f72 4 *11 94 *, 49 102 42 5 2~4 35 7~~~~~~~~~~~~~~'87 9~~~~~9 30 52 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~'1 SI 61FI s 35 t'~~~ ~~ 93.56 ) 20 ~~ 2 92 ~71 1 ,,D 30 t o 2 ,35~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- 56RTUkE COO KIE DATA COMPILED 14 MA 1964 17~~~~ ~~~~~~~~~~, '20 36 '!3 ~ ~ ~ ~32 '20 FR 0 LOG & PLOT OF AT24 3 AU G 1963 Fig. 3. Plastic marker reference grid as dropped from the surface. ''~~ 157 31~~~~~~~~~~~~~~~~~~. ,~ '20 I0~ ~ ~~~~~~~~~~2 / ~ ~~~~~ ~ ~~ ~~~~~~~ Il "'20 1 86 I I~~~, I FORTUNE COOKIE DATA COMPILED 14 MAY 1964 FROM LOG. 9 PLOT 0? ATA 3 ADO 19G.3 Fig. 3. Plastic marker reference grid as dropped from the surface. 157 DYNAMIC ANCHORING OF FLOATING VESSELS K. W. Foster The Baylor Co., Inc. Houston, Texas Abstract Dynamic anchoring was first tried on the "Cuss I" on its initial drilling tests for the Mohole, but the first really successful dynamic positioning system was developed by Shell Oil Company on the coring rig "Eureka". The "Eureka" and the other operational dynamically positioned vessel "Caldrill I" have drilled core holes along the Atlantic, Pacific and Gulf coasts and have encountered a wide variety of weather and sea conditions. The "Terebel", a French built dynamically positioned vessel, has done prelimi- nary testing in the Mediterranean. The operating experience of these vessels is discussed along with a description of this method of operation and limitations of these vessels. Some of the alternate methods of obtain- ing positioning information are discussed along with other methods of applying positioning power. The application of this most interesting development is seen to have a wide variety of applications as station keep- ing in our coastal waters and on the high seas becomes more and more important to our commercial industries and our military preparedness. Dynamic anchoring is a method of autcmatically positioning a floating vessel without the use of anchors or anchor lines. As the name implies, a dynamic anchoring system utilizes constantly varying thrust producing means to hold a vessel in a fixed location on the water against the forces of wind, wave, and currents that tend to move it from the desired location. Man has long desired the ability to position a floating vessel rapidly and in the extremely deep waters of the world without the use of large and awkwardly handled cables or chains and monstrous anchors. Even when using these time consuming anchors and cables, the water depth in which a vessel could be accurately held in position has been severely limited. The first real attempt at dynamic positioning where accuracy of position was a critical factor was on the original "Cuss I" Mohole tests conducted between Guadalupe Island and the Mexican coast south of Los Angeles, California. During these tests, position was maintained by essentially manual control of four harbornaster units attached to the four corners of the "Cuss I" drilling vessel. An indication of position was obtained by radar and sonar signals from a ring of taut line buoys surrounding the drilling location. Although position was maintained sufficiently well to obtain the desired core information, the positioning accuracy was marginal as evidenced by the several drill pipe twist-offs. The first really successful dynamically positioned vessel was the motor vessel "Eureka", Fig. 1, which is a one-bit coring vessel utilizing an APE (automatic positioning equipment) system developed by Shell Oil Co. This vessel which is 136 feet in length and has a beam of 36 feet was placed in operation in May 1961, and has been drilling core holes on the Gulf and West coasts ever since that time. This vessel has drilled core holes in 30 to 4500 feet of water, has held position in wind to 40 miles per hour and waves to 20 feet and has drilled as many as 14 core holes in 158 Fig. I Dynamically Positioned Coring Rig "uea 159 a single day. The "Eureka" is equipped with two 200 hp propulsion drives located in the bow and stern of the vessel. At the present time, the "Eureka" is in the shipyard being jumboized by the insertion of an addi- tional 26 foot mid-body. Additional AC power generating capacity and crew quarters are also being added. In January 1964, the "Caldrill I", Fig. 2, owned by Caldrill Offshore Company of Ventura, California, was placed in operation as the second dynamically positioned vessel. This was the first vessel actually designed for floating well drilling operations to be equipped with an APE system. The "Caldrill I" is 176 feet long, 33 feet wide and is equipped with drilling equipment to permit drilling to approximately 6,000 feet with 4-1/2 inch drill pipe. This vessel was specifically designed to allow drilling, completion and workover operations while automatically positioned, as well as its use as a one-bit coring vessel. The "Caldrill I" has operated all along the Pacific coast, in the Atlantic off the coast of Florida, on the Grand Banks off Newfoundland and presently along the Gulf coast. Position has been maintained in 60 mile per hour winds and 25 foot seas. The "Caldrill" was also successful in drilling core holes with approximately 3 knot currents in the Gulf Stream off Florida. Because of the reliability criteria required for drilling or workover operations on a live well, four propulsion units were used and two com- pletely independent position sensing and computing systems were installed. Any two propulsion units can be used with either of the position sensing and computing systems, thus providing 100% back-up to the normal position- ing equipment. Automatic switchover from one positioning system to the other was also provided. This equipment is almost instantaneous in opera- tion when the vessel is operating in the automatic mode. A third dynamically positioned vessel, "Le Terebel", was placed in limited operation by the French Petroleum Institute in December 1964. This vessel was a converted LCT 85 meters long and 12 meters wide and was equipped with two 300 hp propulsion units driven by diesel engines. The APE system on this vessel is essentially the same as on the "Eureka" and the "Caldrill I" though preliminary testing does not indicate as accurate position keep- ing capabilities. The French Petroleum Institute has been quite secretive about this vessel so no absolute performance data is available. Automatic positioning equipment in its usual form consists of a Position Sensing System, a Computation System and a Propulsion System. These systems may vary widely and still accomplish the same results but all the systems in current use are quite similar. The most conmmn position sensing system is the taut wire system wherein a 1/8 to 3/16" steel cable with a 600 to 800 pound weight attached is hung over the side of the vessel and a constant tension system on board the vessel maintains a constant tension in this wire line of from 400 to 500 pounds. The change in angle of this wire line in two mutually perpendicu- lar planes aligned with the bow-stern and port-starboard axis of the vessel then represents the change in position of the vessel with respect to the weight at the bottom of the ocean. The measurement of this change in angle is accomplished by a position transducer which has an output, Fig. 3, of approximately 100 mv per per cent displacement of the vessel where per cent displacement is defined as the horizontal movement H divided by the water depth D times 100%, Fig. 4. This is equivalent to the tangent of the angle the wire line makes with the vertical and is really more important than the actual horizontal displacement, since drill pipe stresses and other similar factors are effected by the magnitude of this angle rather than the actual horizontal distance. The position transducer has two independent outputs providing a positive DC voltage if the vessel moves aft or toward the port and negative DC output voltages if the vessel moves forward or toward the starboard. The weight on the 160 Fi.2DnmclyPsiindDiln i t Clrl e 161~ BOW STERN STARBOARD PORT IL _.0. -1.0 -.8 -.6 -.4 -.2 0 '.2 *.4 +.6 .8 1.0 0. G. OUTPUT VOLTAGE FIGURE 3 162 BOW TENGNT a i0 o (*)oo0 .DISPLACE6ENT Fig. 4 Geometry of a Taut Wire System 163 bottom of the wire line usually consists of a block of concrete, an old railroad wheel or possibly old automobile blocks. Junk drill bits and other scrap have also been used and usually the cheaper the cost per pound the better. The most successful type of constant tension system, Fig. 5 and Fig. 6, has been found to consist of counterweights moving with- in a king post supporting the sheaves for the wire line. The use of a four part wire line supporting the counterweight allows increased freedom of movement (64 feet on the "Caldrill" and '"ureka") and yet keeps the weight moving slowly enough that acceleration forces may be neglected. No external power is required for the operation of this type of system except for hoisting or lowering to bottom and thus the efficiency is quite high and the operating problems greatly reduced. The remainder of this type of position sensing system consists of hydraulic rams to position the wire line at its operating location and a hydraulic winch to spool in the cable. The obvious advantages of this type of position sensing system are its simplicity and the fact that no active operating elnements are located beneath the surface of the water, thus facilitating repairs or replacement of active elements if necessary. The ease and rapidity of setting up on location is also a major factor as well as the fact that no auxiliary service craft are required. The reliability, simplicity, economy and proven accuracy of this method of position sensing have made it the most widely used method in current use. Of course, other tech- niques such as sonar and radar reflections from submerged or taut line buoys and the use of accoustical signals from submerged transponders offer possible solutions to this problem. All of these systems have their limi- tations and apparent complexities but undoubtedly also have their place in certain position sensing applications. A considerable amount of study has gone into the action of a taut wire line in deep ocean use and a compre- hensive computer program is available to predict taut wire performance. Generally speaking, it appears that position can be sensed accurately within one to two per cent of water depth with the taut wire system and if the current profile is known, correction can be made to give accuracies within one per cent of water depth. Since this accuracy is well within the allowable displacement of a drilling vessel from over the hole, this method of position sensing has become generally accepted in the drilling industry and many indicating and recording instruments are now in opera- tion with very satisfactory results on numerous conventionally anchored floating drilling vessels throughout the world. The computation system on a dynamically positioned vessel usually includes a position indicator to display the position of the vessel in polar form with respect to the desired location, a position recorder to record the vessel's movements with respect to time, and a computer to take the incom- ing longitudinal, lateral and heading error signals and compute the direction and magnitude of the thrust required from the propulsion units to hold the vessel on location or to bring it back on location. As dis- cussed previously,error signals are obtained from the position sensing system as a result of longitudinal and/or lateral movements of the vessel. A heading error signal is obtained from the ship's gyro compass and each of these signals is put in its proper range by appropriate sensitivity, and range selection controls and associated amplifiers. Biasing signals are also inserted so that the operating point may be moved without the weight on bottom being moved and thus allow the vessel to operate with a predetermined angle on the wire line. After these error signals have been suitably scaled and biased, the computer solves the vector equations to arrive at resultant thrust magnitude and direction signals for both the bow and stern propulsion drive units. The computation system also includes circuitry to measure the rate of change of error or the speed of movement of the vessel in all directions and a corresponding increase is made in output signals to the propulsion drives to correct for the anticipated movements of the vessel based on the first derivative of the vessel's movement. This anticipatory sense of the computer allows it to provide much more accurate control and greatly increases its speed of response. 164 Fig. 5 Dual Position Sensing System on "Caldrill I" 165 Fig. 6 Assembly of Counterweight Type Constant Tension System 166 The computer also contains an integrating system or in effect a memory which constantly averages the error in position over a period of time and correspondingly changes the output signals to the propulsion drive units to correct for sustained errors in one direction. This part of the com- puter system makes it possible for the vessel to remain exactly over the hole while still providing maximum thrust on the propulsion drives, thus a constant wind or current from one direction will be automatically com- pensated for by the computer. With this control it is not necessary that the vessel be widely displaced from its desired location in order for the propulsion drive to develop the power required to hold against a constant force. The computer is constantly being fed with varying signals representing the error in the lateral and longitudinal directions as well as an error in heading. Computation is being made constantly with these error signals and a constantly changing output is introduced to the propulsion drive units. This output is in the form of the voltage representing thrust mag- nitude and switch closures representing thrust direction. These signals cause the propulsion drive units to turn in a certain direction and pro- vide the required thrust magnitude. This thrust direction and magnitude is constantly changing to keep the vessel on position, thus the term dynamic positioning. An important aspect of the computation system is the introduction of a longitudinal anti-oscillation bias of opposite polarity to the bow and stern channels so that as the longitudinal error changes from plus to minus and vice versa, the propulsion drive units do not change directions 180� but rather, one simply increases its thrust and the other decreases its thrust an appropriate amount. The effect of this bias is clearly seen in Fig. 7 which shows the typical vector diagrams solved by the computer for various situations. The computation system also includes the various con- trols located in the control console, Fig. 8, to permit manual operation of any of the propulsion drives and numerous indicators to indicate thrust magnitude and direction and other variables. The computer system is made as reliable and fool proof as possible by the use of all solid state circuitry and modular plug-in construction. With reliability such an important factor in most positioning applications, the computation system is no candidate for cost cutting techniques. The best of computers is usually not good enough. The propulsion drive system consists of the motors to turn the screws and adjust the azimuth, as well as associated circuitry and equipment to per- mit starting and stopping the motors, and control of the thrust magnitude and direction as calculated by the computer. On the "Caldrill" and the "Eureka", the main propulsion power, Fig. 9, is supplied by squirrel cage induction motors and thrust variation is obtained by means of oil cooled eddy current couplings. Controllers located with the motor starting equip- ment, Fig. 10, respond to the computer thrust magnitude signals and energize the eddy current coupling with a DC voltage proportional to required thrust. Motor current is monitored and fed back through a compen- sation circuit until the thrust equals the desired amount. On "Le Terebel", a diesel engine's speed is controlled by the computer thrust signal and feed-back circuitry is not used. Thrust direction on the "Caldrill" and the "Eureka" is controlled by a reversible electric motor and a servo feed- back system assures that the direction is maintained as nearly as possible to the computed value. The thrust direction can be changed approximately 10 degrees per second and this appears to be about optimum for control in shallow -- 100 - 1,000 ft. -- water. Higher thrust direction speed changes have been tried and found unsatisfactory. The actual propulsion units on all operating APE systems are right angle drive units; however, this by no means suggests that this is the only usable solution or even the best solution. It simply means that this was the most practical solution at 167 BOW BOW BOW BOW UIIIOILAIINI TIII THIIII lUn LOWOTIC#NL CRROR tL. B ERRoR BOW BOW BOW BOW '#UII1T I~#L$ NO 11mqT NI*IID T UT FINALS T:.IIrIIIIUKA1 mIROR- ' TUiig i:llU Y OU Dlm ILORo TURL N INS ERROR PLUS UIi-OLL'TIrm ONLY ONLY LOIIIIUNAL ERIOR LOIITIUDOINAL taROI ST~ " ~ ~ ~ ~ ~ ~ IrL ERN STLERNL r Sr!RN SrERN ~ bS"ERN STERN Fig. 7 Vector Diagrams for Position Keeping 168 Fig. 8 Control Console on "Caldrill I" 169 Fig. 9 Propulsion Drive Unit on "Caldrill I" 170 171 1 i' the time for these particular units. Many other types of propulsion drive units have been investigated including DC motor drives, variable voltage AC drives, and cycloidal propeller drives. Each of these systems has signifi- cant advantages and undoubtedly each will find its place in the dynamic positioning picture of the future. We have seen the beginning of a new technology in vessel positioning and can only dream of the many possible applications of this technology to our industrial and military requirements. As we move forward in our unending efforts to "Exploit the Oceans" for the good of man, I believe dynamic anchoring will play an ever increasing role. 172 ROLE OF GOVERNMENT IN OCEAN FISHERIES EXPLOITATION -- AN INDUSTRY VIEW Lowell Wakefield, President Wakefield Fisheries, Port Wakefield, Alaska Abstract No attempt will be made this afternoon at broad review of the subject assigned me. Rather, I will describe in some detail two federal activities which interfered rather beneficially with the conduct of our business. I have reference to the survey of unutilized bottom fish and crab resources in the Gulf of Alaska and in the Eastern Bering Sea conducted by the Bureau of Commercial Fisheries in 19140 and 1914-l and to the agreements reached In 1964+ and 1965 between the United States, the Soviet Union and Japan regarding the harvest of King crabs off the Alaska Coast. A discussion of these two projects will illustrate my~ thinking on the proper role of government in ocean fisheries exploitation. I want to make it clear that these are personal views. I represent no group or organization, I will nevertheless also comment on what I regard as industry's proper attitude towards what it views as government's responsibilities in this field. THE BEGINNINGS Thirty years ago there was no U. S. crab industry worth mentioning on the West coast or in Alaska. Plants in Peters- burg, Wrangell and Cordova canned a few cases of Dungeness each year. A few hardy souls had tried to locate King crabs, but most of us in Alaska had never heard of or seen one. Total U. S. Crab meat consumption was a paltry ton Million pounds of canned, almost all brought in from Japan, and about eight million pounds of fresh, mostly from Blue crabs here on the East coast and from the Gulf states. Today the U. S. is not only the biggest market, but leads the world in crab meat production. Alaska alone produced over thirty million pounds last year, more than our two biggest competitors, Russia and Japan, combined, and we have hopes the resource will sustain double the present level of fish- ing. Crabs are now number two in Alaska's biggest industry, fishing, and their harvest is revitalizing the whole econow7 of the state. Alaska's historic complaint against the fishing industry has been that we brought the cannery crews and fish- ermen North in the spring, harvested the salmon, the codfish, the halibut and the herring, then took the people, the pack and the money South in the fall. In ninety years we built almost nothing of permanence; few homes, schools, roads, towns. A cannery, a dock and a watchman to check the pad- locks were our legacy. Crab fishing, however, goes on all twelve months of the year, peaking in the winter. Only local labor and resident fishermen make sense. Fishing towns and villages on the Gulf of Alaska coast and out the Aleutian chain have come alive. When our firm rented space to start processing crabs in the halibut cold storage at Sand Point fourteen years ago, the population was fifty seven. Two months ago we hosted a plane load of state and federal of fi- 173 cials, including Governor Egan, Senator Gruening and Congress- man Rivers, come to sit down with us in the assembly room of the Sand Point school and plan for more housing, better com- munity facilities, for a village already grown 700 per cent. WHO TO BLAME? Fixing responsibility for this sorry state of affairs is difficult. Some people even blame me, and the charge is seldom denied, for it seems to help sales of our particu- lar brand of merchandise. The truth is that many people, many circumstances and much luck have been involved. The most significant single factor, in my opinion, is the two- year investigation of the crab resources off the Alaska coast conducted by the U. S. Fish and Wildlife Service just before World War II. In 1930 a Japanese cannery ship with a fleet of small fish- ing boats showed up off our Pribilof Islands. By 1935 there were seven in the Eastern Bering Sea, concentrated just north of the Alaska Peninsula in the outer reaches of Bristol Bay. The red salmon runs there are still one of the most valuable fish harvests on either coast of North America, and most of us believed the Japanese were out there to intercept our fish. Tempers flared. One rugged individualist, Captain John Shields of the codfish schooner Sophie Christiansen, telegraphed for guns and ammunition to arm his dorymen. The anguished cries were heard here in Washington. Secretary of State Hull made strong protest. The Japanese ships withdrew. In the course of the excitement it was learned the Japanese were not fishing our s almon. They were canning something we didn't even know was there, King crabs. It seemed obvious that an Alaska resource which supported seven fleets employ- ing over two thousand fishermen and cannery workers might afford opportunity for domestic industry, especially since the product was destined for export to the United States. President Roosevelt became interested and Congress appropri- ated sums totaling $125,000 to investigate the King Crab re- source of Alaska. The Fish and Wildlife Service chartered a small cannery ship, the 396-ton Tandelayo, and the Dorothy, a 93 foot schooner built in New England in 1903, and equipped with sideset trawl gear. They worked the summer of 1940 in Pavlov Bay on the South side of the Alaska Peninsula and in Alitak Bay on Kodiak Island. In both places, the Dorothy managed to catch enough for the technologists to perfect can- ning techniques for a product as good as or superior to the canned crab being imported. That part of the project was then terminated to concentrate on a broad survey to define the limits of King crab distribution, to attempt to indicate where they concentrated in quantity, and to develop better fishing methods. The following spring the Dorothy was joined by the Locks a 58 foot antique Puget Sound dragger and the Champion, a small herring seiner built in the 20's. Aboard each boat was it's regular commercial fishing crew of seven, a gear technologist, a marine biologist. Quarters were cramped, primitive forecastles with none of the amenities. FANTASTIC COVERAGE In the next seven months those boats turned in one of the most outstanding exploratory fishing surveys in history. They fished with tangle nets, with trawls, with crab pots. 174 They fished Southeastern Alaska, Prince William Sound, Kodiak, the Aleutians, the Bering sea; thousands upon thousands of miles of rugged coastline, hundred of thousands of square miles of fishing banks, They counted and measured and ana- lyzed. They told us where the King crabs were, and also the other crabs, and the flounders and the perch and the Alaska pollock and the codfish. They missed a little on quantities available, for they couldn't tarry to work a school intensive- ly as a commercial fisherman does, but had to move on. After twenty years, the fastest-growing fishery under the American flag, plus a great deal of additional research, has come up only with revalidation of their findings. Without this modest research program the single most important industry to the economy of our new state of Alaska would like- ly never have come into being. What made government's effort so remarkably successful? I believe that (1) It was well planned. (2) It had good luck. The resource it sought was there. (3) It had very little money. The field work was all done by chartered commercial boats and crews. The results were directly translatable to industry terms. Love of money may or may not be the root of all evil, but lavish facilities can inhibit as easily as foster research activities. I have fished on the Champion. There is no comfortable place to lie down or sit and read a magazine. There is nothing you can do on her, but fish. If a single one of the lovely research vessels coming off the ways these days ever comes within 25 per cent of the research results per dollar achieved by the 1941 survey, I undertake to trundle Don McKernan in a wheel barrow from Interior to Harvey's and pay for his dinner. (1) Industry took advantage of the research work, and under- took the long expensive job of commercial development. There is a lot of talk about government's responsibility to industry. There is little talk about industry's responsibili- ty to government, or even to itself. In the late summer of 19)1, Ira Gabrielson, then director of the Fish and Wildlife Service, overnighted at Port Wakefield, where I was superin- tendent of the herring saltery and meal plant. We talked of the very interesting findings of the King crab survey and Dr. Gabrielson pointed out that if no one in industry did anything about it, the research money would have been wasted. I said, "Tell the boys to throw ashore here all the gear they are going to discard when the survey is completed, and we will see what we can do." During the next few years we experimented in a small way with fishing and canning, and also learned King crab meat could be frozen. Right after the war, Harry Guffey, who skippered the Locks on the survey, built a small, integrated factory trawler, and I a larger one - a 140 footer. Ellsworth Trafton, captain of the Dorothy, converted a surplus mine sweeper to the same use. We began working the crab grounds of the Eastern Bering Sea, and Alaska had a new industry. A NEW THREAT In 1964, this new industry was seriously threatened by the pro- liferation of Japanese and Russian fleets off the Alaska coast. Ours had become strictly a pot fishery, and gear conflict with the trawlers was inevitable. Nor is the foreign tangle net fishery for crabs compatible with our pots. The Japanese had re-entered the fishery in 1953, but on a modest scale with a single mother-ship fleet. They agreed to Joint study of the resource and the few areas of direct conflict were adjusted 175 equitably. In 1959 the Russians entered the fishery and were up to three big fleets in 1963. The Japanese countered with more fleets and higher quotas. In four years, the foreign catch of Alaska King Crabs jumped from two to nine miflion. We were in danger of being crowded off our own grounds. The Department of State first brought the Russians to Juneau to discuss gear conflict off Kodiak, got agreement that has almost eliminated crab pot losses in that area. Then we sat down here in Washington with the Japanese in the fall of 196W+ to discuss limitation of their Alaska crab fishery. We came out of that meeting with a two-year agreement barring them from 99 percent of the grounds on which we depe~id, reducing their catch quotas, and subjecting them to a strict ~conservation regimen. Later that winter a similar session with the USSR produced a parallel agreement. Without question, these are a series of the most successful negotiations ever undertaken by the U. S. to protect one of its commercial ocean fisheries interests (or the interests of any of its other industries, for that matter). What was responsible for this remarkable success? TIHE POOR FOLKS Success in 1965 was born of the same ingredients as success in 19W1. (1) Careful, long-range planning, coupled with lots of luck, put us in a strong bargaining position. In 1958, the law of the Sea Conference in Geneva adopted a convention on the continental shelf which assigned living organisms in con- stant contact with the sea bed to the adjacent coastal nation. Some years later, scientists of the Bureau of Commercial Fish- eries assembled evidence that some of the crabs - King certain- ly-, Dungeness probably, came within the definitions of the con- vention. Our good friend Bob Bartlett, senior United States Senator from the State of Alaska, put through a bill providing the mechanics of enforcement. (2) The anti-poverty campaign has not yet reached the offices in State and Interior handling international fishery matters. Our delegation chairman at all these sessions was B ill Herrington, ably backed by Dan McKernan at the last two. With little budget and a skeleton staff, and a thousand other matters crying for attention, they worked nights and week-ends to hammer through to agreement with a sense of urgency affluence might dull. (3) The indus- try attempted to assist government in the discharge of its re- sponsibilities. The presidents of the two largest companies in the field and the State of Alaska's Commissioner of Fish and Game sat through all the sessions as working members of the team, and instead of making cheap headlines back home about the bureaucrats selling out the American fisherman, they took the heat back home for the compromises necessary to get agreement. Private sector and government sector are so intertwined today that one could talk all afternoon about government's responsi- bilities in ocean fishery development. I think myr two illus- trations demonstrate that our government is capable of dis- charging its responsibilities for research to foster new in- dustry and protection of that industry once developed remark- ably well, especially if industry will cooperate. 176 FISHERY SCIENCE AND THE PREDICTION OF COMMERCIAL FISH LANDINGS Gordon C. Broadhead Van Camp Sea Food Company Division Ralston Purina Company ABSTRACT The practical value of fishery science data is examined in relation to the prediction of commercial fish landings. Examples are taken from the shrimp and tuna fisheries of the United States and the anchovy fishery of Peru. A general discussion of forecasting techniques is given. INTRODUCTION Much of the justification used by Government, university, and industry scientists for funding ocean research is based on the premise that know- ledge of the sea and its occupants is of practical value to military and commercial interests. Today, I would like to limit my discussion to that segment of ocean research which relates to fish and shellfish resources and to consider if there is value to industry in these studies. Ten years ago it was generally felt among industry people that the results of fishery research were interesting, but seldom could one use the results of this research to solve specific management problems concerned with raw material availability. Fishery scientists readily admitted that their accomplishments in the area of predicting resource availability were minimal. The reasons for failure are clear: 1. There was a lack of current synoptic information on the physical pro- perties of the air and ocean. 2. There was a lack of basic research into the life histories of the animals under consideration. 3. There was a lack of understanding and interest by fishery scientists in the application of their findings to the forecasting of fish landings, 4. There was a lack of clear communication of the existing information to industry people in a form that they could understand or use. 5, There was a lack of currency in the data that was transmitted to the fishing industry. Most studies that related to the prediction of fish supplies utilized historical information, and findings were published years later. 177 During the past ten years, we have made rapid advances in certain of these areas. The amount of money spent on ocean research related to fisheries has increased many fold. The results are encouraging. For example, synoptic charts of sea surface temperature are now available on a current basis for most areas of the Pacific Ocean. increased research budgets for the Bureau of Commercial Fisheries, international fishery commissions, and universities have resulted in substantial additions to our fund of basic knowledge of the life histories of the commercial species of major importance to the United States fishing industry. New resources have been discovered and are now being utilized by industry. The communication of current and useful information to industry has greatly improved in recent years. The results of tuna research directed toward predicting seasonal availability of skipjack in Hawaii and albacore off the Pacific west coast are published regularly. Landings of shrimp by port, by species, and by size count are published daily by the New Orleans Market News Service.* Catches of yellowfin and skipjack in the eastern Pacific area are published weekly by the Inter-American Tropical Tuna Commission. There is still, however, only a modest interest among fishery research groups in the development of forecasting methods. This is to be expected and, in my opinion, the fishing industry should not rely on research people who are removed from the day-to-day activities of the industry to solve the problems of forecasting fish supplies for them. It must be a cumulative effort with each group contributing in their own area of com- petence and need. Here the sea food industry is lagging badly in its attention to this vital area. When the Van Camp Sea Food Company Division decided three and a half years ago to test the theory of linking Government and industry studies in the forecasting of fish availability, I had little concept of the problems to be encountered or the methods to be used in solving these problems. Further, management at Van Camp had nothing more concrete than an educated hunch that efforts in this direction would be worthwhile. Today, I would like to mention some of the results that have come from our attempts to benefit from the $150 million spent in the United States each year by federal and state agencies in marine research. First, we should examine the areas of knowledge useful to fish forecasting: 1. Knowledge of fishery science methods to permit interpretation and evaluation of the research work being done by Government and university groups 2. Special interest in the dynamics of fish populations 3. Understanding. of oceanographic and meteorological data so that the effects of the environment on fish populations may be evaluated 4. Knowledge of fishing vessels and fishing methods 178 5. Interest in the economics of the operations of fishing vessels and of processing, distribution, and marketing of fishery products 6. Knowledge of statistical techniques and data reduction methods. Secondly, we should ask what methods are useful in the forecasting of commercial fish landings. For illustrative purposes, it would be best to take a single fishery and to outline the full range of background studies, information needed, calculations, predictions, and evaluation of results. I will not do this as the results of our efforts are not public information. What I will do is to take examples from several fisheries to illustrate techniques. As background, it is essential to assemble all the existing information on the fishery. This will permit evaluation of the state of scientific know- ledge concerning the fishery. For the larger fisheries in the United States, such as shrimp and tuna, this background material is extensive. It permits a pinpointing of key areas to be considered and an opportunity to note the areas of weakness in the scientific information. FISHERY EXAMPLES Shrimp - The shrimp fisheries of the Gulf of Mexico have been studied intensively during the past ten years. Excellent statistical information on landings is available on a current basis. A historical study of supply-demand-price relationships in the United States reveals that the year-to-year fluctuations in the supply of shrimp from domestic sources are the key factors in determining trends in price of raw material. We also noted from the biological data that: 1. Fishing effort for the three major species--brown, white, and pink--in the Gulf of Mexico has reached a level where further increases in fishing effort have a minor effect on total landings 2. The major share of the landings are from the initial age group. Total stock mortality (from fishing and natural sources) is extremely high and the recruits to the fishery are cropped off as they enter the fishery 3. Fluctuations in year-class strength vary by a factor of two in pink shrimp, three in brown shrimp, and six in white shrimp. The fluctuations are related to environmental changes With this basic knowledge concerning the importance that yearly fluctu- ations play in shrimp prices and the knowledge that these fluctuations are environmentally induced, we can narrow our area of investigation. Because we are dealing with essentially the recruits each season, it is useful to examine several preseason indicators of year-class strength developed by the Bureau of Commercial Fisheries's scientists in the Galveston, Texas, laboratory. They have found that indices of abundance of brown shrimp at the postlarvae and juvenile stages of their life history provide clues to the success of the commercial fishery for adults. 179 Tuna - Albacore supplies are the most critical to the tuna industry as this is the only species which can supply white meat needs. Light meat tuna can be packed using yellowfin, skipjack, bluefin, bigeye, and albacore. Again, as in shrimp, there is an abundance of background scientific material. The most productive albacore fishery in the world is the north Pacific Ocean. Fish from this stock is harvested by pole and line on both sides of the north Pacific and by longline in the western and central north Pacific. Scientific studies by the California Department of Fish and Game, Oregon State Fish Commission, United States Bureau of Commercial Fisheries, and the Japanese Fishery Agency have shown that a common stock is being utilized. Length frequencies indicate that a major share of the landings are from three year groups. These are the two and three year old fish on the United States side and the three and four year old fish on the Japanese side. Fluctuations in year-class strength vary by a factor of two to three. As these groups remain in the United States fishery for four years and in the Japanese fishery for five years, it is possible to use the measure of year-class strength of one year old fish to forecast the next year's two year old abundance, the two year old fish to forecast the next year's three year old abundance, and so on. In addition to the basic abundance of each year class, it has been shown that water temperatures play an important role in the availability of the albacore to the fishery each year off California, Oregon, and Washington. The beginning and end of the season are related to sea surface temperature, and the development of the fishery off Oregon and Washington is parti- cularly dependent on the northern extension of the warmer isotherms during August and September. Knowledge of the basic abundance and availability of the albacore is, of course, valuable, but one must also estimate the prices to be paid during the season and the amount of fishing effort that will be attracted to the fishery. These latter two factors are of great importance. High prices and increased fishing effort can make a year of poor abundance one with average landings. Peruvian fish meal - Knowledge of changes in availability of raw material to our fish meal plants in Peru is of great value. Six years of intensive study by the Instituto del Mar del Peru and F.A. 0O. research people have provided an excellent store of basic information on this anchovy resource. Statistical studies indicate that a level of maximum equilibrium yield has been reached in this fishery. Landings peaked at 8.8 million metric tons in 1964 and have declined slightly since that time. At the present level of fishing intensity, fluctuations in catch are due largely, in my opinion, to changes in year-class strength. Years when the sea surface temperature has been colder than average during spawning season--July through September--have produced poor year groups while years of warm temperature anomalies during spawning have produced good year groups. In recent years the fishery has been supported by only two groups: the recruits and the adults from the previous year's recruitment. The recruits 180 first appear in November and December (age six months) and by February and March are contributing a substantial tonnage to the catches. Careful monitoring of this new age group each year provides information of a use- ful predictive nature. Environment also plays an important part in the availability of the anchovies to the fishing year. The El Nino condition which develops periodically off Peru seems to adversely affect availability during the July-October period. It is obvious, then, that careful monitoring of sea surface temperature, year-class strength, and fishing effort can assist in the prediction of anchovy landings in Peru. SOME SUGGESTIONS FOR FISH FORECASTING 1. Useful forecasts cannot he made from a desk position. Intimate knowledge of the operational aspects of a fishery is required. 2. Interpretation of data requires a mixture of science and art. Use computers for data reduction only as feel for the information is lost if machine methods are employed at the forecasting level. 3. Government reports provide a sound base, but it is almost always necessary to supplement these data with a private information network. 4. Only limited significance should be placed in daily news. There is generally too high a noise level in this type of data. Trends based on weekly or monthly summaries are more reliable. 5. Word of mouth information should be used with caution and then only if the source is firsthand and is known to be reliable. 6. Do not attempt to exceed the limitations imposed by the data. Some situations do not yield to the use of predictive methods. SUMMARY If industry actively evaluates Government research, supplements it with additional analytical work, and applies the results to assist in business decisions, then we can state with emphasis that ocean research programs have very great value to the sea food industry. 181 MINING INDUSTRY'S ROLE IN DEVELOPMENT OF UNDERSEA MINING Gordon O. Pehrson Corporate Vice-President International Minerals and Chemical Corp. Skokie, Illinois ABSTRACT A review is made of what the United States Government and others are doing to aid the mining industry in establish- ing an off-shore mining capability. This newly developed know-how combined with the development activities of private mining/oil/chemical companies will lead to an orderly estab- lishment of off-shore mining operations. Some economic, technical and marketing aspects are reviewed to give a clearer picture of the attractiveness and pitfalls associated with ocean mining. Also, recommendations addressed to the public as well as private sectors are made to speed along this new opportunity. INTRODUCTION I think the time has arrived when the mining industry can look upon ocean mining with "cautious optimism". For those people who place great value on statistical figures, we can state that today, in the entire world, some 50 million dollars worth of mineral products are mined directly from the sea annually. Furthermore, based on facts already obvious today, total world ocean mining within 10 years will have over 250 million dollars in annual value. In 15 years, probably over 500 million dollars annually. Whether or not you put weight on figures such as these is not too important. We feel that there are more tangible reasons for giving marine mineral mining a good hard look. Certain mining companies, such as those dealing with sulfur, and tin are already forced to look into the sea for their only logical large future sources. There are more mining companies, who for defensive reasons, must, if nothing more, have a good working knowledge of the competitive position of those marine minerals that would eventually enhance or destroy their busi- nesses. In order to do a good job on that alone requires some rigorous effort. There are other reasons as well. Consider the fact that international trade and more intense business competition in the years ahead will place a heavy burden on shipping material at low cost around t he world and that means filling the voids in backhauls. In many cases this means looking into the ocean for minerals where nothing else exists on land along the trade routes. And last but not least, we cannot overlook the value of marine minerals to underdeveloped nations as well as have- not nations to whom a marine mineral, whether high grade or marginal, can mean the difference of successful inter- national trade or not. 182 So the mining industry, which for many years has been aware of its global interests, must now look at mineral recovery with a new twist: Can an ocean resource compete with a land source in the world market? My purpose today will be to call your attention to the recent development in ocean mining which will aid the mining industry in evaluating this new potential and also offer some opinions, humble as they may be, that will aid in opening up this new potential to the American mining industry. Let us begin by looking at our government's role in this whole picture. By a stroke of fate, the Thresher sub- marine tragedy made us painfully aware that our working capability in the ocean environment was very limited. Somewhat frightened by the fact that the Russians might salvage or photograph the wreckage before we would, the U. S. Navy about five years ago embarked on a rigorous technical campaign dealing with the ocean environment: 1) To eventually operate a submarine at all depths 2) To gather the facts of the ocean--its currents, temperatures, physical attributes, etc. 3) To detect foreign objects,their movements and cognizance 4) To survey our adjacent ocean bottoms (first the continental shelves and the deeps) 5) To properly maneuver, navigate and operate military systems in the ocean environment A broad based technological effort such as this has many ramifications. The Navy has had to deal with biological, physiological, engineering and scientific groups to resolve the myriad of problems that confront us in mastering the military aspects of the ocean environment. Fortunately, these same technological advances can be applied to marine mineral technology. We have been made painfully aware again, since the Thresher incident, that we have a long, long way to go before we can locate objects at sea, much less haul them up. We need not treat the nuclear device in the Mediterranean ocean nor the crash of a commercial jet in Lake Michigan in August, 1965, with too much detail to remind us of our national limitations. But let us look at the positive side of the ledger. At my latest count there were some 17 agencies of the Federal Government that are actively engaged in developing technology to deal with the ocean environment. It would be tedious to list them all. What would be interesting would be to high- light the progress that has been made by these groups in the last few years. The most glamorous, probably, has been the recent success of SEA-LAB II which proved that man can perform a number of physical and mental tasks under 200 feet of water for longer periods of time without too much discomfort. Next year this test will be extended to over 400 feet depth and I think it will be safe to predict that the United States will have the capability to successfully "man" the continental shelf up to the 600 foot depth level by 1970. 183 Secondly, the National Science Foundation has launched the Mohole project. This is destined to generate an immense amount of information on the geology of our earth as well as make considerable technology available to a number of industries, such as ours, on how to maintain heavy mobile equipment over a specified area at sea for great periods of time. The Bureau of Mines, with its Marine Mineral Technology Center at Tiburon, California, in concert with our company International Minerals and Chemical Corporation and the Lockheed Aircraft Company, have developed coring and probing devices and simple air lifts in the past year which are helpful in evaluating ore bodies that lie on or near the continental shelf surface. Further plans call for more development in this same vein and the tools and methods will get more sophisticated as we go along. The United States Geologic Survey, the Coast and Geodetic Survey as well as the Corps of Engineers, have over the past four years, put some effort into exploration for minerals on our continental shelves and have reported a number of mineral and natural resource discoveries that look interest- ing. More of such activities by these agencies is on the books. The National Oceanographic Data Center in Washington today provides us with a reasonably good compilation of world- wide oceanographic data which is exchanged with all the nations of the world which generate or need their own data. This year, the NODC is now including geologic data with the core samples to be stored by the Smithsonian Institute. The United States Civil Engineering lab at Port Hueneme, California and the Naval Electronic lab at San Diego, has also made many contributions to science and technology applicable to undersea mining in their work dealing with corrosion resistant materials, mechanics of materials studies, underwater communication and visual detection mechanisms, and stabilizing structures at great depths. The newly formed Environmental Science Service Administration of the Department of Commerce has formulated ambitious plans in the Sea-Air Interface studies which will aid tremendously in understanding weather conditions at sea and also give us a better handle on environmental conditions in the open sea. This list of highlights can go on, of course, but sufficient evidence indicates that Uncle Sam is beginning to make a rather sober appraisal of his newly "won" terrain. All the knowledge that is thus developed, short of that which is considered secret in the national interest, will be made available to industry. This substantial beginning, on the part of the Federal Government, must now be married to private industry's effort to exploit the sea. What is holding it back? 184 Probably the greatest single reason that ocean mining has not taken a more aggressive path is that, to date, no major deposit of any real value has been found. The fifty million dollar market served by present and underwater mining ventures around the world are, for the most part, unique local deposits which serve local markets. The notable exceptions are tin and sulfur. As a matter of interest, it should be stated that recently some seven companies have bid over thirty-three million dollars for sulfur mineral leases in the Gulf of Mexico. This probably represents the largest single development effort to date in terms of money, for an undersea mineral deposit. However, we feel that most of the other mining operations around the world are too marginal in economic return, especially if we consider the risks involved with the open sea. But we are of the firm opinion that once a substantially rich deposit is found that the technology to exploit it will be readily developed. At least for the continental shelves. But unless such a large and rich deposit is found, ocean mining development will continue to move rather slowly and rely, for the most part, on the military fall-outs from anti-submarine warfare technology. Another serious impediment to a more rapid ocean mining and exploitation effort is the legal aspect. Who owns the ore body that has been found? Most of the seashore states in the Union other than Oregon and AIaska have not established a firm law concerning mining leasing rights and the Federal Government also has failed to establish a policy of ore body ownership that is acceptable to ex- ploration and mining risk takers. Fortunately for us, this whole subject will be treated in greater detail later this morning by a much more qualified individual. The real essence of ocean mining success or failure, or if you prefer a more modern jargon, is it GO or NO GO, rest basically on simple economics. These are economics as they apply to the mining company on land just as equally as they do for ocean consideration. A case in point: A number of marginal copper mines have re-opened in thelast two years because the price of copper has risen from 289 to 429 per pound. By similar corollary, off-shore phos- phate nodules near San Diego, California, are not being mined because phosphate from Florida and Idaho are being delivered at lower prices to California markets. There is not much mystery surrounding the technology of extract- ing these nodules from the ocean floor. It is straight forward economics on the final product that favors one resource location over another. Ocean mining, however, has got some good things in its favor which do not necessarily hold for land locked resources. A substantial part of any major mining scheme are the costs associated with housing and services for the miners' community, the laying of railroad track, harbor facilities, trucking equipment and the like. These capital charges are usually compounded by the operating costs added to the production cost for moving goods from the mine site to the cargo carrier (specifically cargo ships). 185 Any ore body that is high enough in grade and found in more than 30 feet of water can avoid these considerable expenditures. In some cases, even shallower water, would permit the use of ocean going barges to short distance ports. An off-shore mining scheme would also be re-usable and transferrable. This means a lot, should a mining operation be located in a politically unstable area. And how many mining companies wished they could move their expensive mine shafts after a mine has "played out"?! Now let us set aside all these considerations and look at ocean mining development from an entirely different view- point. Those of us in management are always beset with those managerial problems that are straight-forward and those that are new, untested, or unknown. I am addressing myself now specifically to the risk-taking or the entre- preneural aspects of running a mining operation. (Slide 1) Let us look for a moment at the projected slide which shows how we see the ocean exploitation industries broken down. This is a matrix describing the service and extractive activities that completely blanket this 'business arena". There are nine basic industries (as we see it) now involved in ocean exploitation. These are the basic industries that produce products for commerce or perform the vital functions that are part and parcel of the ocean environ- ment. These are industries listed across the top of the slide from left to right. I think they speak for them- selves. Acting as crosscuts to these basic industries are the industries that provide the specialized services necessary to complement the primary ocean business activity. On the left hand column, the HARDWARE cross-cut pertains to those companies that build the ships, the floating plat- forms, the instruments and the tools necessary for the basic operation of the industries listed across the top from left to right. In the SYSTEMS cross-cut, we are talking about companies that develop navigation systems communication networks, diving services and techniques, supply services and other similar activities. In the area of KNOW-HOW, we speak of those companies or indiv- iduals who have a specific knowledge to sell or supply. This would include patents, operations assistance and guidance, scientific services such as seismic interpreta- tions and the like. It also includes the knowledge developed by institutions such as Scripps and Woods Hole pertaining to geologic finds or general oceanographic methods. In PROPERTIES are those individuals or companies that deal in minerals leases, land ownership, harbors and even the financing for the purchase or use of these facilities. For the TRADING cross-cut we include all those commercial services that pertain to the trading function, such as selling the minerals, promotion, financing the trading itself and so on. 186 Now for the Mining industry, there are companies in existence today that perform these service functions for the ocean environment. They are available to the other basic industries as well. Now in developing this particular theme with you, I offer the suggestion that future marine mining ventures will be born from any one of six directions: The basic mining industry itself or from any one of five service industries on the left. While this is being done now with ordinary land mining, I submit to you now that this procedure will work even more so with ocean mining. I think the reason for this is rather apparent. The mere size of the ocean itself, being 2-1/2 times greater than our land surface, means that one company or even a few companies can not hope to cover this entire area by themselves. And I'm speaking now from both a geographical as well as a commercial standpoint. The concept staggers the imagination! ! Inputs to a major mining company for an off-shore opportunity must come from as many reliable sources as possible for proper assessment. Otherwise the costs would be astronomical. And I include inputs from the various governments as well as private business. To put it even more candidly, there are a number of mining companies who now own leases for off-shore property. But they are waiting for someone to develop an economic mining system that can economically extract the ore body. There are some mining companies who are developing hardware for marine application and waiting for someone to approach them with an interesting underwater ore body discovery. And there are some mining companies who are assessing the economics of certain off-shore raw materials and are waiting for the right opportunity to present itself for commercialization. A mining company is prone to move cautiously in this regard under any circumstance, because even if a good deposit is found, what chance still exists that the com- petition will find an even richer deposit somewhere else? This same problem exists with land deposits but there, a mining company, has a number of basic tools at its disposal to more critically assess that possibility. These tools are still lacking for ocean bottom resources. We have some other thoughts on ocean mining that we would like to share with you. After much discussion with our- selves and others in the mining industry over the last few years on this subject, we get the impression that nobody seems to know how to grab a hold of this subject. Well, let's discuss it some more and look at its numerous parts. We are even willing to stick our necks out a bit to bring a point across. Mathematics and Operations Research have played a vital role in the mining industry over the past ten years. I won't attempt to treat that subject other than to point out some work done by tTW-B Nolan of the U. S. Geologic Survey and Allais of the French Geologic Survey. 187 Nolan showed that the distribution of mining value followed a Poisson Distribution. Or in simpler language, he indicated that in any given large mineralized zone, most of the mines have relatively small value, some have good values, and only a few mines produce immense value. Nolan's chart dealing with California, Arizona, Nevada and Utah dramatize this point rather well. Allais did some unique mathematical interpretation on geological anamolies in the Sahara Desert and also observed that the distribution of these anamolies follow a Poisson distribution. (Slide 2, Slide 3) The next chart on the screen is still another example. Allais listed the mineralized wealth of many major areas of the globe in terms of dollar output per square kilometer. This collec- tion of areas was extremely large. He only considered those geographical entities larger than 100,000 square kilometers and some larger than a million square kilometers. The small- est area was Malaysia and the largest, the entire Soviet Union. Again, the same mathematical distribution pattern appeared. Well, what we would like to suggest, based on this bit of interesting information, is that some types of mathematical relationships exist for ocean bottom minerals. We have already done some interesting work in the mathe- matical treatment of ocean mineral deposits and have found, with the aid of computers and data received from the National Oceanographic Data Center in Washington, as well as our own data, the oceanographic factors do inter-relate. We see the mathematical approach to finding ore bodies as a valuable tool and intend to do more as more and more information about the ocean environment becomes known. As an interesting corollary to this subject of mineral pro- ductivity is the one of agricultural productivity. This too has special significance to our company since our basic busi- ness is the production of certain minerals for the soil to improve crop yield. (Slide 4) The percentage of the earth's surface that is available for agricultural purposes is small indeed and that portion that is truly high for the production for food is smaller yet. This awareness of the distribution of arable lands is essential to fostering a sound agriculture policy around the world, both from a business as well as political standpoint. (Slide 5) Another avenue for looking at the future of ocean mining is from the technology viewpoint. We have decided to dream about what is going to happen in the years ahead and offer this table for consideration. Now I don't doubt for a minute that there are many of you in the audience who will challenge some of this prognostication but we will stick our necks out anyway -- primarily to inspire those that now are total skeptics. 188 We can see that for the most part, underwater mining activities can be operated for a number of ore situa- tions in 50 feet of water or thereabouts. The litera- ture already cites a number of mining operations around the world, almost all of which are in 130 feet of water or less. The newly developing submarines that will be able to take samples by coring as well as the new coring methods applied from surface ships will make us aware of mineralized areas in 300 to 600 feet of water by the 1970's. The chart indicates that the necessary technology to complement most of the mining opportunities will be ready by then. At least we like to think so. There is another interesting attribute to recovering minerals from the ocean shelf; one that deserves the attention of any company which has interests in the field of ocean resource recovery. Our beaches in the United States, especially those on the Atlantic Shelf are being eaten away by wave action and other causes. Cities that lie on the shoreline find themselves limited for expansion because the ocean represents a great share of the city's periphery. Many of the great harbors of the world are being silted up and/or find them- selves too shallow to handle the newer and immense cargo vessels now being built. The point to be made is that near shore ocean mining opportunities very often can be joined with other commercial activities that can enhance the economic return of a mining venture. It can also reduce the business risk of such undertakings. In some cases, it can even be that the on- shore aspects of off-shore mining can be a more lucrative aspect of this business. We can take this thought one step further and suggest that the technology essential to off-shore mining can be applied to non-mining problems such as harbor and channel maintenance, under-water construction, land reclamation, improving near shore navigation and so forth. These all represent interest- ing diversification avenues for those companies that find themselves interested or capable in off-shore mining. No one here will deny what new and lucrative businesses have cropped up with the off-shore oil industry. We hereby imply that similar activities will grow from mining oppor- tunities. In closing, I would like to repeat my beginning thought: that ocean mining today should be viewed with "cautious optimism". The reasons why this new endeavor looks more and more attractive as the years progress is as follows: 1) It will be possible to develop certain mineral properties submerged under sea water and get them to market at competitive capital and operating costs. 189 2) The world's continental shelves alone represent an area of about 10 million square miles. This is a new continent worthy of development. Suf- ficient evidence exists to establish that a number of interesting minerals are there. 3) Because of certain political instabilities around the world, ocean mining opens up nearby resources heretofore locked in distant lands. It also permits plant and capital to be partially salvaged in case of economic and political difficulties. 4) It presents the opportunity for profits in spite of the obvious risks of working in the open sea. And last, but not least, we hear the words "vast", "rich", "unlimited" and so on used rather loosely while discussing ocean minerals. While we tend to be optimistic about the oceans resources, we must also be realistic enough to know that this is not the language of significance. Let's be realistic about approaching the mineral values of the ocean environment in relation to the cost to extract them. Using this cautious attitude, there seems little doubt that a potential is there and that the American mining industry can have a leading role to play in this relatively new opportunity. 190 BASIC SCIENCE FISHING, and SERVICE OILUGAS MINING FOOD CHEM. SHIPPING DEFENSE SPORT SALVAGE TECHNOLOGY HARDWARE / SYSTEMS KNOW-HOW PROPERTIES TRADING THE OCEAN EXPLOITATION INDUSTRIES DISTRIBUTION OF MINING -CALIFORNIA DISTRICTS ', 38,500 Sq. Mi. . .. .T. B. Nolan 1950 40 NUMBER 40 OF ---ER NEVADA and UTAH 30M~. 46,500 Sq. Mi. DISTRICTS 30 20 ARIZONA- 'O 40,600 Sq. Mi.. .s . 10 , :'ee 0 $10, 000 $100,000 $1,000,000 $10,000,000 Over to to to to to $100, 000, 000 $10, 000 $100,000 $1,000,000 $10,000, 000 $100, 000, 000 DISTRICT PRODUCTIVITY DISTRIBUTION OF MINERAL VALUE OVER VERY LARGE 24 -- AREAS ('100,000 SQ. KM.) - -M. Allais (1957) 20-- NUMBER OF AREAS 16 GREATER THAN 100, 000 SQ. KM. CA 12 200 400 600 800 $ ORE VALUE I SQ. KM. (Greater than) ~~~~1~~~~~ - - To,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~,z OCEAN MINING TECHNOLOGY TIME TABLE DEPTH OF WATER 50' 300' 600' 1000' MINING USING AIR LIFT DEVICE 1960 1970 1975 1980 MOBILE MINER (OCEAN FLOOR) 1970 1972 1975 1980 BARGE DREDGE LIFT 1900 1970 - - STATIONARY MINING PLATFORM 1960 1970 1975 1980 BOYANT SUBMERSIBLE SYSTEM - 1975 1977 1980 UNDERWATER OPEN PIT HARDROCK MINING 1975 1985 1995 2005 UNDERWATER "AERIAL" PHOTOGRAPHIC RECONNAI SANCE 1960 1964 1970 1975 EXPLORATION SUBMARINE (CORER) - 1968 1968 1968 UNDERWATER SITE DEVELOPMENT STATION 1970 1972 1975 1980 SOLUTION MINING (SULFUR, POTASH) 1961 1980 1985 2000 HARDROCK MINING (BELOW SHELF) 1900 1985 2000 2000 MINING SHAFT 1970 1980 2000 2000 I-.~~~~~~~~~~~~C THE GOVERNMENT'S PROGRAM FOR ENCOURAGING TEE DEIELOPMENT OF A MARINE MINING INDUSTRY By Walter R. Hibbard, Jr. Abstract Present emphasis in the Goverment's program for encouraging the develop- ment of an industry based on exploitation of marine minerals is determined by two principal factors - (1) the unavailability of the kind and quality of information required for sound economic evaluation of sea-bottom mineral deposits, and (2) the physical difficulty and high cost of obtaining such information. As knowledge and understanding of mineral deposits in their marine environment increases, program emphasis will shift to technologic problems of production. The Job of finding and delineating sea-floor min- eral deposits and developing the technology to produce from them, economi- cally, the mineral raw materials the Nation needs is formidable. Its successful accomplishment will require that the combined capabilities of Federal and State agencies and the academic community be brought to bear in an aggressive partnership effort with private industry. The Government's marine minerals research program is considered to comprise three phases which are interrelated and more or less interdependent. These can be characterized by their objectives: (I) Marine Minerals Search and Exploration, (II) Marine Mineral Deposit Delineation, Evaluation and Development, and (III) Marine Minerals Production System Technology Development. Ultimately, as with dryland mineral resources, the bulk of the activity in all of these areas will be by industry. At the outset, however, the Government must contribute a substantial effort in all three phases. In discussing with you "The Government's Program for Encouraging the Development of a Marine Mining Industry," I will be speaking primarily in terms of the Bureau of Mines activities with which I am most familiar. Other Federal agencies are, of course, also at work in this emerging field of technology--or at least in areas related to it--and, while I do not presume to speak for them, I shall describe briefly some of the efforts being made to coordinate parts of their operations with those of the Bureau and its industrial cooperators. Those of us in science and engineering who have been working along the fringes of oceanography have long been intrigued with the great oppor- tunities to be met in the sea. Having read and heard of the mineral wealth of the sea floor, we cannot help but look hopefully in the direction of this prize bounty. As world population increases and the corresponding needs for mineral raw materials grow, we are at last being compelled to turn to these new, unexplored regions, as a means of augmenting and expanding our domestic resource base. Now that we have begun to partici- pate more fully in the National Oceanographic Program, we have come to learn what the pioneers in oceanography have known all along, namely, that opportunity is present but will be realized only after the challenges of a research development and testing program have been successfully met. By combining the talents of Government, industry, and the academic com- munity, we believe technology can be sufficiently advanced to make marine mining practical enough economically to attract the large amounts of private risk capital that will be required for full exploitation. 197 The Bureau of Mines is helping to initiate these early stages of what we believe will eventually become a growth industry. We hope that marine mining will gradually expand into a major force in the international economy. We are, however, becoming increasingly aware of the questions that must be answered first. Our program, currently being conducted cooperatively with three leading industrial firms, is still essentially in the embryo stage. The Bureau of Mines has a small operation at its Marine Minerals Technology Center, at Tiburon, California, where we are refurbishing and equipping as a research center the former Navy Net Depot. We have already had assistance from fellow member agencies of the Interagency Committee on Oceanography: a 65-foot Army T-boat; and a 165-foot reactivated Navy net tender, both of which have been modified and refitted for the specialized work that will be required as the program moves forward. Mining on dryland is a costly and financially risky activity. This is so despite the fact that we are able to call on technology and engineering capability stemming from thousands of years of practical experience and engineering progress. In the marine environment, where we have as yet so little understanding of the complex environment and where we have virtually no mining experience, the risk is multipled many times. Research effort, it therefore seems to us, can reasonably be shared by industrial, academic, state, and federal entities--by all who have a concern in the future. Our knowledge of marine mineral resources is limited but I'm sure we all are enthusiastic about developments in the recovery of shallow water minerals near shore. Recent efforts to develop gold production in Alaska's Norton Sound certainly have generated as much interest as the actual pro- duction of tin, iron ore, diamonds, aragonite, and construction minerals. If shallow water beach and stream placer deposits are abundant, then there is a basis for at least a small industry in the near future. Interest has also been stimulated in the deeper water chemical precipitates. As you know, some areas of the Continental Shelf, such as offshore banks, are thought to be covered with phosphorite. Some of these deposits are reported as only a few hundred feet deep, and may eventually be fully ex- plored and evaluated for their potential use as fertilizer material. I'm sure that all of us who are familiar with the literature have been made aware of the deposits of nodules containing manganese, nickel, copper, and iron, which have been found in non-depositional areas of the ocean and purportedly over two miles deep. They appear to be so abundant that they have sparked commercial inquiry in recent years. If the deeper marine mineral deposits are as plentiful as they appear to be, then the long range potential rewards certainly must be commensurate with the extensive research and development that must be undertaken. Bringing a sea bottom mineral deposit into production will require the same sequence of basic steps as does developing a mine on dry land. First, obviously, a deposit has to be found--the discovery step. Next, the deposit must be explored to obtain data on extent and quality sufficient to make a market study and a preliminary economic Judgment. Then, if this Judgment is favorable, additional sampling and measurement must follow to develop the detailed knowledge required for sound evaluation in terms of technology and economics . . . . to define the physical and chemical characteristics of the ore body and to learn as much as possible about its environment. Only after successful completion of this step, called delineation, can design of the production system and development of the deposit for mining begin. 198 These three stages of mineral deposit development are obviously applicable to any mineral occurrence, whether on dryland, the ocean bottom, or the moon. If we look at the technologic requirements for marine mineral mining in terms of the objectives of these stages the pattern for the required marine mineral research program becomes apparent. The problems to be attacked will fall into one of three categories or phases - (I) Search and Exploration, (II) Delineation and Evaluation, and (III) Production System Design. As far as the Department of the Interior is concerned, responsibility for research in phase I, Search and Exploration, rests with the Geological Survey. Both the Survey and the Bureau of Mines are concerned with the second phase, Delineation and Evaluation. Research related to the deposit of mineral production systems falls within the mission of the Bureau of Mines, as would the development of technology for processing the ores after their extraction. Obviously the research in these three categories is interrelated and more or less interdependent, as are the corollary steps in the development and operation of a mine. They are considered as separate subprograms because of their relative priority with respect to time and their different require- ments (and opportunities) for coordination and partnership operations with industry, the academic community, and other Government agencies. Initial emphasis in the Bureau of Mines program for marine minerals is dictated by a very limited amount of definitive knowledge with respect to sea bottom mineral resources. Such information as we have is sketchy and qualitative, as might be expected because the bulk of the data were devel- oped incidental to scientific investigations directed toward other aspects of the sea bottom. Only in the past decade has any effort at all been focused on marine minerals. Not only is information on ocean floor mineral deposits sparse, but the tools and techniques for sampling in sufficient quantity and quality are not available. Only a thorough knowledge of the character of marine mineral deposits and the particular ocean environments in which they occur can support the sound economic Judgments that must precede capital invest- ment, without which a production operation cannot be established. But as yet, knowledge of these factors is required to define the specific techno- logic problems for which research must seek answers as the first step in developing commercially attractive marine mining systems. The most urgent immediate need, then, is research and development on the problems delineating and evaluating marine mineral deposits. It is in this critically important area that most of the Bureau of Mines present effort is concentrated. The work falls into two principal categories: (1) Data Collection and Analysis and (2) Sampling Equipment and Methods. In the first of these, liaison is being established and procedures developed for obtaining, from those of the oceanographic community who are generating it, available data on known and potentially mineralized areas. We are collecting much information as possible on those characteristics of marine mineral occurrences and their environment that will affect the design or limit the operation of a mining system, including data on mineral quality and distribution, water depth, weather, tides, local water circulation, sea bottom topography, and physical characteristics. All of these factors will be important in determining the physical requirements of the pro- duction technology. Assembly and analysis of adequate data for specific mineralized areas will provide the basis for defining the mining problem and for preliminary economic studies. 199 In this activity, the Bureau obviously must depend heavily on the Geological Survey and other Federal agencies such as the Environmental Sciences Service Administration, and the Navy as well as State agencies, universities, and private institutes engaged in oceanographic studies. Work under one second category, development of equipment and techniques for sampling sea bottom mineral deposits, also will proceed much faster and more efficiently as a partnership venture. Here, industry already is a principal participant, and its participation can be expected to increase. The Bureau has a long history of cooperating with industry in research that has proved both productive and mutually advantageous. We are confident that this practice will be as successful in building a foundation for com- mercial mining of the ocean as it has in previous dryland activities. The present pattern for Bureau research in marine mineral sampling reflects the present state of the art and the fact that so little is known about marine mineral resources. Though we have not yet evaluated all available ocean bottom sampling devices, a preliminary review indicates their in- adequacy for delineating certain types of marine mineral deposits in the detail and precision taken as a matter of course on dryland. I do not mean to say present tools are of no use at all. They are. But obtaining ocean bottom samples for scientific study and taking mineral deposit samples to determine the economics of a mineral production operation are two altogether different things. Indeed, it would be surprising if the tools already available were adequate since they were developed for other purposes. Inadequate knowledge of marine mineral resources limits the present scope of the research on deposit delineation because obviously all of the problems cannot be defined until deposits have been identified. Accordingly, because some of the same sampling tools required for deposit delineation will be useful in marine mineral exploration and because our sister agency, the Geological Survey, is responsible for the search and exploration phase of the Government's program, we have proposed the Bureau's work in developing sampling equipment be initiated in a joint project at the interface between the missions of our two agencies. In addition to the Survey, we have invited appropriate State agencies and industry to Join us in a systematic effort to sample, in reconnaissance fashion, the most favorable areas on the continental shelves. The work in many cases will follow up leads furnished by reconnaissance sampling already a matter of record, such as the Geological Survey Woods Hole study of the Atlantic Coast Continental shelf and slope. The program will locate and define, in a preliminary fashion, potentially economic sea bottom deposits in conjunction with the sampling research. This approach permits us to make our research effort do double duty. By testing and evaluating equipment on sampling campaigns planned by Survey and State geologists we not only will accomplish our objective but will add to the fund of marine mineral resource information necessary for guidance of our future work. Cooperative arrangements for participation of industrial concerns in this project will differ somewhat from our usual practice because of the nature and broad scope of the work. Normally our cooperative research is con- cerned with specific technologic problems. Such research may concern a particular mineral deposit in which the cooperating group of companies has an interest, but the cooperative effort is designed to acquire knowledge 200 Il that will have wide application. In contrast, the research here is con- cerned with a relatively broad field of engineering, presently in the embryo stage, relating to mineral resources of which specific deposits have not yet been developed. Furthermore, one of the objectives is infor- mation on the resources themselves. In the aggregate these differences probably account for the wide interest that we have found industry showing in the work. We are talking with a number of companies who have evinced an interest in Joining the cooperative program that already is underway. Fortunately this is a program that can be open end. The size and duration of the effort need be limited only by the research requirements and the amount of funds and other resources we can bring to bear. Any strengthening of this effort will advance the beginning of commercial marine mineral production. We will therefore welcome proposals for additional participation. As work on this project progresses and more information on marine mineral resources developed by the Geological Survey, industry and others working in the field becomes available, the shape of the Bureau of Mines marine minerals program will gradually evolve to conform to the usual Bureau pattern. It will be concerned with specific deposits that are typical with respect to a significant resource and specific engineering and tech- nologic problems related to delineation, evaluation and exploitation of these deposits. Similarly, the opportunities, and the requirements, for industry participation can be expected to change. Naturally we do not expect any one industrial concern, or even a group of companies, to contribute to or participate in all of the marine mining research we contemplate. A company's interest normally will be limited to those projects which may contribute to solutions for problems anticipated in its own future operations. In the aggregate, however, industrial interest and participation should cover almost as broad a spectrum as that of the Bureau. The growth will probably take place on a project-by- project basis, however, as has been the case in our other research programs, rather than by widening the area of inquiry of the sampling project to which our industry partnership is now confined. Industry participation in various future projects will no doubt vary as widely as it does in our other work, where it ranges all the way from the provision of company sampling data for trend analysis studies by Bureau engineers to the full financial support of Bureau research on a rock mechanics problem of mutual interest. As I have already indicated, the development of sampling equipment con- stitutes only part of the research that will be required to solve the problems of marine mineral deposit delineation and evaluation. Though these problems cannot be defined in detail until more is learned about the resources and their environment, some areas where work will be necessary and productive are apparent now. Determining the topography and physical character of the sea floor obviously will be a necessity. Some of the existing geophysical tools such as-- density probes, underwater cameras, and manned submersibles, will be utilized and, with modification, doubtless can be made more useful for mineral deposit delineation. But the precision that will be required in making these determinations, and the necessary measurement of additional properties such as particle size, hardness, and strength, make it inevitable that new tools and instrumentation will have to be developed. 201 The character and properties of the superJacent water mass also will have to be determined in detail, because such factors as local patterns of water circulation and corrosiveness of sea water will be as important as the physical parameters of the deposit itself in designing and evaluating production equipment. Here again, though some of the tools we need are available they will, without doubt, need to be supplemented. Even after the first generation of adequate tools and techniques has been developed for delineating marine mineral deposits, further research will be necessary because their application almost certainly will be slow and expensive. And unless the costs of this preliminary step in developing an ore deposit can be reduced to something approaching a reasonable figure they will form a major obstacle to early and orderly development of our marine mineral resources. After a few deposits have been probed by sampling equipment and we know a little more about their physical characteristics and the nature of their environment, we can direct our research efforts toward the technology and economics of production. Our present activity in this area is limited to a comprehensive and detailed background study of available equipment that might be used in marine mineral production systems. We plan to collect, analyze, assemble, and publish everything we can obtain on the operating characteristics and limitations, both physical and economic, of dredges, 6ffshore drilling equipment, floating work platforms, working submersibles, pumps and hydraulic slurry-transport systems. The results of this study, when correlated with the physical parameters of both specific and typical marine mineral deposits, will permit reasonable economic Judgments and also provide a sound basis for further research in the technology of marine mineral production. Until such an analysis can be made this latter phase of the research program cannot be planned in detail. Nevertheless, we can foresee the broad areas into which the work will fall. Research leading to efficient methods for breaking sea-bottom ores will obviously have to be undertaken but the urgency of this problem cannot be determined now. It is probable that, for some time, attention will be directed principally to unconsolidated sediments. It is safe to assume, however, that some sea floor mineral deposits will be consolidated and sufficiently competent to require breaking or, if unconsolidated, will contain particles large enough to require fragmentation into sizes small enough to handle. Efficient economic fragmentation will probably be the most difficult obstacle to overcome in developing systems that may ultimately make possible the mining subbottom hard rock deposits, not accessible from shore by underground workings. Development work on sea-bottom-rock fragmentation will, of course, have to be preceded by basic studies of rock behavior in an ocean environment. Another important element in any mining system, and one which will be critical to the economics of a marine system, is materials handling, or the gathering and transporting of minerals from the ocean floor. As with fragmentation, details of the research that must be done will become clear as work progresses in the exploration and delineation phases of the program. The design of vessels to meet the special requirements of the mining situation is another important area for research and development. The Bureau of Mines does not have any active work in this area. We do intend 202 to develop some capability in the field however, in order to evaluate existing and newly developed equipment with respect to the requirements of mineral production systems and furnish specialized guidance to those already active in the design area. We propose to accomplish this by developing a close liaison with commercial shipbuilders, the Navy, and the others who have outstanding capability in ship design. Requirements for research in mineral processing will become apparent as our fund of knowledge about marine mineral resources grows. In general, we plan to undertake such research as the need arises, and the initial studies are expected to differ little from those we now perform on minerals derived from dryland deposits. But, since it will be economically advantageous in many situations to do as much as possible of the processing at the mining site the factors of sea conditions and logistics will have to be considered. In these instances, equipment and processes will need to be piloted under simulated and actual sea conditions. Research on the problems of waste disposal will be a major element of the program, since unwise dumping of the tailings, if not carefully planned, could quickly foul a mining operation. Furthermore, the compatibility of a marine mining operation with exploitation of the other resources of the sea, particularly the food resources, will depend principally on the effectiveness of the tailings-disposal system. The results of research on near-shore-sediment movement and other oceano- graphic studies will be useful in attacking this problem. Hence, close coordination with research organizations working these fields will be required. Early liaison with those of the oceanographic community whose interests lie with food, recreational, and other resources of the sea will also be necessary. The purpose of the Bureau's marine mining research program is to encourage and assist in the early development of a domestic, privately-owned-and- operated marine mining industry. Attention will be directed initially therefore to those minerals most likely to become commercially attractive first, such as the shallow water tin and precious metal placers, con- struction materials, phosphorite, and other industrial minerals. We believe that the technology required to exploit our marine mineral resources will develop most rapidly if, within the framework of market demands, the effort starts at the shore and progresses outward. Such an approach can reduce the technologic risk and provide a sound basis of experience for the incremental advances in production technology that will be required as we move out to deeper water and into more difficult physical situations. Ultimately the bulk of the Bureau's research in the marine minerals field will be concerned with the technology and economics of production. Right now, however, the state of the art and lack of adequate knowledge of the resources themselves make it necessary that most of our effort be devoted to acquiring the information that will enable us to define the mining problems. And defining the problems is, in itself, a major task. The work will be difficult and costly, as will subsequent efforts to develop production technology. We are confident, however, that the partnership approach will yield solutions to these problems, on schedule and with minimum risk, and that the prize will be well worth the effort. 203 LEGAL CLIMATE FOR UNDERSEAS MINING Abstract Elmer F. Bennett The Public Land Law Review Commission, created in 1964, has been charged by Congress with making a study and recommenda- tions concerning the disposition and restrictions on dis- position of mineral resources in the Outer Continental Shelf. The sovereignty of the United States over the area appears well-established in international law, although certain ambiguities do exist and the United States has international obligations with respect to mineral operations in or over the continental shelf. Existing legislation and regulations do not make specific provision for underseas mining. There are at least seven basic elements to a favorable legal climate for industry participation in underseas mining: (1) certainty concerning sovereignty; (2) the right to develop minerals discovered; (3) adequate tenure and right to develop mineral reserves to offer reasonable opportunity for profit; (4) definite royalty obligations of reasonable magnitude; (5) certainty concerning relative obligations of the federal government and industry in complying with international law; (6) certainty concerning interruptions in the use of parts, territorial sea and internal waters; and (7) certainty con- cerning applicability of labor legislation and other domestic laws. As you may know, I am presently serving on the staff of the Public Land Law Review commission, a temporary agency created by Congress in 1964 to study and recommend any needed changes in the laws, rules and regulations governing the administration of the public lands of the United States. Since nearly every- one is aware of the activities of the Forest Service, the National Park Service and the Bureau of Land Management as they affect the daily lives of millions of people within our national borders, it may seem questionable whether a dry land lawyer like myself has a proper role on your program. Actually, Congress decided we did when it passed the legislation creating the Commission. Most of you have some familiarity with the Outer Continental Shelf Act (67 Stat. 462, 43 U.S.C. Sec. 1331) which established a leasing system for minerals in the continental shelf beyond the areas ceded to the states by the Submerged Lands Act some- times known as the Tidelands Act. Section 10 of Public Law 88-606 (1964) charged the Public Land Law Review Commission with review and recommendation responsi- bility for "the disposition or restriction on disposition of the mineral resources in lands defined . . . as being under the control of the United States in the Outer Continental Shelf". 204 Thus it is clear that the Commission's dry land staff lawyers must get their feet wet in sea water and consider the complex field sometimes called the legal order of the oceans. in addressing ourselves to the legal order applying to under- seas mining we are attempting to find our way in what was almost entirely an uncharted wilderness before World War II. Fortunately, however, there are a few signposts which have been since erected because of the pioneering efforts of the oil industry. The immense values of underseas oil deposits have provided the necessary incentives for national govern- ments to consider the problems inherent in bringing order and security to the exploitation of submarine mineral re- sources. Progress in resolving these problems is slow, but the stakes are so high both for industry and our nation that we cannot afford to make mistakes in law or policy that may well plague us for centuries to come. The fact is that over two-thirds of the earth's surface is submerged, and over half is under 10,000 feet or more of water. As the world's population grows, we most certainly will devour at an increasing rate the minerals of the earth's land masses. in these circumstances it is readily seen that mankind may one day soon rely on submerged resources for a major part of life's mineral requirements. Short-range policies in the international arena must be adopted with an eye on long-range needs as well, since what we do today as a nation will set a pattern for other nations to follow. And what we claim today as a nation we cannot deny to others to- morrow. Perhaps the best example of the international effect of our national claims is the growth of the concept of the "outer continental shelf". By treaty in 1942 Venezuela and Great Britain each annexed one-half of the submarine area underlying the Gulf of Paria. Nevertheless, the primary impetus in f or- mulating the concept came in 1945 when President Truman issued a proclamation declaring that the natural resources of the subsoil and seabed of the continental shelf contiguous to the United States were subject to the jurisdiction and control of this nation. By 1956 some twenty-five nations had claimed unilaterally varying degrees of exclusive rights to the exploitation of resources in submarine areas of f their coasts. Within five years after President Truman's proclamation authoritative com- mentators were writing that customary international law included the principle that coastal nations have exclusive control over adjacent submarine areas. international lawyers often speak of the exclusive and inclusive claims and interests of nations. At the risk of oversimpli- fication let us define an exclusive claim as the asserted power of a nation to exclude other nations from use of or authority over 205 an area or specified activites. By the same token an in- clusive claim is the assertion by a nation of the power to share with other nations equal use or authority over specified areas or activities. Historically, the legal principles governing the vastnesses of the oceans have resulted from the interaction and conflict between the exclusive and inclusive claims of the nations of the earth. The great nations have recognized the oceans as common resources essential to commerce and commnunication. on the one hand, each has had vital interests in exclusive con- trol over access to its coasts and natural resources of the adjacent sea upon which its people may be dependent. On the other hand, each has had so-called inclusive interests in free, nondiscriminatory use of and access to the oceans and their resources. Generally, the historic great powers have considered their interests in unrestricted access and use to outweigh their interests in excluding others from use and access, except where national security is endangered. Consequently, international law is generally said to favor and protect the principle of "freedom of the seas", and the recognized exceptions thereto have been relatively limited in scope, at least in times of peace. For purposes of classifying the varying legal authority of coastal nations the seas have been divided into zones of con- trol. Today these zones are classified as "internal waters", "territorial sea",* "contiguous zones", and the "high seas". On the high seas a coastal nation can be said to have legal authority in time of peace only over vessels it registers and allows to fly its flag, with minor exceptions only, such as the right to suppress a Pirate ship. As a ship approaches closer to a coastal nation that nation's authority increases until it reaches internal waters where the power of total exclusion is nearly absolute. While these distinctions are important to underseas mining because of the necessity to use the oceans as highways and supply stations for mining operations, the principles involved are well-enough established so that industry can effectively measure those risks when contemplating investment. Today's uncertainties are primarily related to the use of the seabed and subsoil and the removal of the mineral resources themselves. With respect to exploiting underseas mineral resources it is now clear that coastal nations have exclusive control over exploration and exploitation on the continental shelf, even when the area extends beyond their internal waters and their territorial seas. The principles inherent in this rule of international law were set forth in the Geneva convention on the Continental Shelf, adopted by the United Nations Conference on the Law of the Sea, on April 29, 1958. 1 should add that at least thirty nations have ratified or acceded to this convention, including the United States, Soviet Russia and the United Kingdom, and it is now in effect. 206 I should make clear that the extent of the continental shelf over which coastal nations have exclusive sovereign control is not governed by geological criteria. Article I of the Continental Shelf Convention defines the shelf as extending beyond the territorial sea "to a depth of 200 metres or, beyond that limit, to where the depth of the superjacent waters admits of the exploitation of the natural resources of the said areas...." Article II of the convention makes it equally plain that a coastal nation may exclude anyone from developing the resources of the shelf without its consent, and its legal rights to do so do not depend on occupation or proclamation. There are certain limiting provisions in the convention which should be noted: (1) The legal status of the "superjacent waters as high seas, or that of the air space above those waters" is not affected. Article 3. (2) The coastal nation may not impede the laying or maintenance of submarine cables or pipe- lines, except to the extent of "reasonable measures" for exploration and exploitation of the shelf resources. Article 4 . (3) Exploration and development of shelf resources must not result in "any unjustifiable inter- ference with navigation, fishing or the con- servation of the living resources of the sea..." Article 5(1). ;4) Such activities must not result in "any inter- ference with fundamental oceanographic or other scientific research carried out with the in- tention of open publication." Article 5(1). But the consent of the coastal nation must be obtained before undertaking such research. Article 5(8). (5) While shelf installations and devices may be installed and 500-metre safety zones created around them, permanent means for warning of their presence must be maintained. Article 5(5). And they must not be established "where inter- ference may be caused to the use of recognized sea lanes essential to international navigation." Article 5(6). (6) The coastal nation is obligated to undertake in the safety zones "all appropriate measures for the protection of the living resources of the sea from harmful agents." Article 5(7). 207 Because of the tremendous investments involved industry must have assurance that certain interests will be protected in the event of successful mineral discovery. The interests are essentially the same as those traditionally important in mineral operations. The differences are mainly in degree, but established legal methods are not necessarily adequate. The Outer Continental Shelf Act makes specific provision for oil, gas and sulphur leases. That Act also authorizes the Secretary to grant leases on the basis of competitive bidding for the development of "any mineral", but the Act is silent as to the terms and conditions the Secretary may prescribe. (43 U.S.C. Sec. 1337). No detailed regulations have been issued by the Secretary to implement his authority. (43 C.F.R. Sec. 3382.1 et seq.) There can be little doubt that Congress had liquid resources in mind when the Outer Continental Shelf Act was enacted. Underseas mining operations for non-liquid min- erals may present very different problems. For example, mining operators undoubtedly need exclusive pos- session of mineral deposits to be worked, whether submerged or not. Ordinary police protection, however, would not be adequate in the case of submarine operations. Even the identification of predators might well prove impossible. To what extent will self-help be allowed in such situations? Even seemingly unlikely questions like this can prove very troublesome later. Fortunately, gatherings of experienced operating and professional people like this audience will stimulate solutions in advance of the problems, since our nation has the opportunity to legislate for submarine mining before technology has advanced to the point where submarine exploitation on a commnercial scale is feasible. Basic elements of a favorable legal climate must be developed before we can expect industry to undertake the risks of under- seas mining. The first of these basic elements, in my view, is certainty con- cerning what sovereign has the legal competence to authorize and regulate the mining of continental shelf minerals. As I indicated before, that seems clear enough, at least as long as operations are conducted at substantial distances from potential boundary claims of other coastal nations. In the absence of international agreement, or "special circumstances", Article 6 of the Convention on the Continental Shelf provides that shelf boundaries of coastal nations shall be determined as "equidistant from the nearest points of the baselines from which the breadth of the territorial sea` of each is measured. Of necessity this language incorporates the ambiguities of baseline determination under Articles 3 and 4 of the Convention on the Territorial Sea and the Contiguous Zone, a companion to the shelf convention now in effect among twenty-seven nations, including the United States. suffice it to say for our purposes that anyone operating on the continental shelf in proximity to another nation does so at the risk of international complications unless a shelf boundary agreement 208 has been reached among the nations concerned. Little will be done by industry to explore continental shelf areas unless assurance is given of the right to develop min- eral resources discovered in the course of exploration. This is the second basic element of a favorable legal climate for underseas mining. A third basic element is that industry must have sufficient tenure after discovery to provide an opportunity to recoup its investment with a reasonable opportunity for profit. This element necessarily implies the right to develop mineral re- serves reasonably necessary for that purpose over time. Other- wise it is nonsense to talk about industry participation in shelf development. Because of the international obligations of the United States I mentioned previously, there are obviously serious questions connected with any suggestion that fee simple rights be conferred like those under our public land mining laws. On the other hand, millions of dollars have been invested by the oil industry on the continental shelf on the strength of leasehold estates. The real key must be certainty of rights and certainty of obligations, whether by lease or otherwise. A fourth basic legal element, which has an economic root, is that payments for the right to exploit continental shelf minerals must be readily measurable and reasonably related to the risks and investment required in underseas mining. If the payment is indefinite or exorbitant in relation to these factors, industry can be expected to direct its efforts to more orthodox and less hazardous enterprises. A fifth basic legal element is reasonable certainty with respect to industry's detailed responsibility to operate in conformity with the international obligations of the United States. For example, it is apparent from the pertinent conventions that the United States must not allow pollution of ocean water so as to endanger the living resources of the sea. Another typical ques- tion is whether an industrial operator must pay for the relocation of a submarine cable where that relocation is reasonably necessary or convenient for the purposes of mineral exploration. Also, what assurance will the operator be given that the government will require such relocation if necessary to the mineral opera- tion. The Continental Shelf Convention prohibits "unjusti- fiable" interference with navigation, fishing and conservation of living resources of the sea. But what are the justifiable interferences that our government will allow? All this must be spelled out in arrangements between the government and industry, or industry participation may well prove to be only a pious hope. A sixth element is that industry must have assurance of reason- able rights to the contiuous use of ports, the territorial sea and internal waters. If operations can be shut down for national defense reasons, for example, for how long and under what con- ditions can this be done? 209 A seventh element is that industry should 'have certainty con- cerning the applicability of our domestic laws. For example, to what extent will our maritime labor laws apply to under- seas mining operations. To what extent will the laws of adjoining states be applicable to continental shelf mining. The utter dependence of underseas mining operations on port bases and water-borne supply calls for clear answers to these jurisdictional questions. My catalog of basic legal elements of a legal climate that will encourage industry to enter into underseas mining is by no means comprehensive. But those I have mentioned are certain to enter into the business decisions involved in pioneering the way for maximum private development of our continental shelf resources. As an individual privileged to serve on the staff of the Public Land Law Review Commission, I know that consideration will be given in our studies to the views and interests of all groups interested in the mineral and living resources of the continental shelf. Your suggestions for our studies will be most welcome and you are invited to contribute pertinent data and recommenda- tions as well. 210 SOME ASPECTS OF WAVE FORECASTING ON THE PACIFIC COAST Richard Kent and R. R. Strange Oceanographic Services, Inc. Abstract The discussion is confined to wave forecasting on the Pacific Coast of the United States. Because of the large number of weather patterns that can exist over the Pacific Ocean, it follows that a given forecast site may be vulnerable to waves of many differing origins, several of which can occur simulta- neously. Major weather patterns providing waves on the Pacific Coast and typical resulting waves are described. Major difficulties in providing reliable forecasts and re- quirements for improvement are outlined. I. INTRODUCTION To all who work in the marine environment, the value and utility of an accurate wave forecast is obvious. More often than not, the difference between success and failure is a knowledge of the sea and weather conditions which are likely to be faced during a given operation. Yet, in spite of its importance, wave prediction technology remained at a veri- table standstill until the era of World War II when the importance of low wave conditions to successful amphibious landing operations was painfully realized. Historically, wave prediction technology was placed on a reasonably firm footing by the pioneer work of Sverdrup in the U.S.(1942), and Suthons England (1945), who combined physical theory with available empirical data to provide working, fairly reliable, forecasts for military landings in the African, European, and Pacific World War II war theatres. These early efforts were followed by several revisions on the basic theme in the late 1940's and it was not until the early 1950's, more-or-less, that radically new and improved theories and techniques were proposed and developed by Longuet-Higgins, Cartwright, Pierson, Neumann, Darbyshire and other workers in the field. These latter theories now are well developed and form the basis for modern wave forecasting procedures. It is clear, of course, that regardless of how refined or precise the wave forecast theory is, the fundamental require- ment for a reliable wave forecast is an accurate weather forecast, since it is the winds themselves which produce the waves. In fact, once the weather forecast is made, the task of making the wave forecast is somewhat rote. The real problem, then, is to predict the space-time wind field. As will be discussed later, a good meteorological input is reasonably easy to provide where the data density is high, as is the case for the Atlantic and Gulf of Mexico areas. Conversely, where the data density is very low, as for the Pacific area, the task of predicting weather patterns often requires that the forecaster be scientist, swami, and gambler. 211 Aside from the military, non-military users of wave forecast- ing information are many. Reliable forecasts are invaluable to the offshore oil industry in everyday operations, as they are to harbor operations, dredging operations, fishing operations, shoreline development, marine construction, ship traffic, and recreational activities. In view of the pronounced trend towards the sea that is taking place through- out the country, it seems reasonable to expect that wave forecasting will find many more uses and demands in the future. The purpose of the following presentation is to describe certain basic aspects of wave forecasting on the Pacific Coast of the United States and Canada. The discussion briefly outlines those meteorological conditions which are the important wave producers for the subject area, describes characteristics of these waves and their effects on various offshore operations, and finally, dwells upon some of the outstanding difficulties involved in providing wave and weather forecasts on the Pacific Coast. The art of making forecasts and the various theories involved therein are not discussed in this presentation, since they in themselves constitute lengthy treatises. Suffice it to state here that forecasting techniques used by most forecasters are composites of the more important theories, modified on the basis of field, experience. II. GENERAL WEATHER AND WAVE CLIMATOLOGY In this section of the paper, a brief discussion of the major weather patterns which produce important waves is presented. The mean atmospheric pressure and mean wind direction in the Eastern Pacific during January (winter) and July (summer) are presented in Figure 1. The position and intensity of the Pacific high pressure cell is of utmost importance in terms of storm activity on the Pacific Coast. This warm, subtropical high has a mean position a few hundred miles west of Southern California during January. Similarly the large relatively uniform mass of cold air which overlies the north polar area spreads southward during the winter. The southern most boundary of this polar air is termed the polar front. Along this front, extratropical cyclones or low pressure areas form and intensify as a result of the interaction between the cold polar air to the north and warm tropical air to the south. These extratropical cyclones represent by far the most im- portant source of waves reaching the west coast during the winter, when, on frequent occasions, these storm systems move onshore between Northern California and British Columbia. Some- times, particularly when cyclogenesis occurs in the far Eastern Pacific, these storms move as far south as Southern ia ifornia. In summer, the Pacific high shifts far to the northwest and intensifies markedly, and the storm track then shifts far to the north. Consequently, only relatively few storms move southward as far as Washington and Oregon. During this time of the year, the Pacific high becomes the dominant wave generator. Variations in size, intensity and position of this high pressure area can mean the difference between extremely high northwest seas or nearly calm conditions. The problems for the forecaster in predicting the behavior of this high can be much more difficult, at times, than problems 212 - - g. 1 I- -- ,. - 9 9 -. / ---L-- lURE 1 AN RESSU AND W ND DIR CTION, JANUAR / ;--r - _ 2 /02 FTC R B BAN SlUR D RE ION, A GUST 213 associated with the prediction of the extratropical cyclones and winter storms. Speaking of the wave climate in broad scale terms, very gradual changes in wave characteristics occur in going south- ward along the U. S. Coast; the mean swell direction, for example, shifts from west-southwest off Northern Washington to west off Oregon, and to northwest off Central California; the frequency of high southerly seas generated by winter storms decreases southward, and the frequency of high north- west seas in the summer increases southward to about San Francisco. However, a very marked discontinuity in wave climate occurs along the California coast south of Point Conception (located at 34.5 North, 120.5 West). The area immediately north of Point Conception is, with local exceptions, fully exposed to swells generated by the Pacific storms and which approach the coast from directions between southwest and northwest. At Point Conception however, the coastline cuts sharply eastward, affording protection against swells arriving from angles of greater than 285 . Further protection, particularly for the area southward from Los Angeles, is provided by the Santa Barbara Islands. The wave situation often is reversed during the summer when southerly swells of moderate height hit the coast of Southern California. In most cases, these swells are generated by tropical storms originating off the coast of Central America and traveling northwestward off the Mexican Coast. Swells from thesg storms approach Southern California at angles of 160� to 180 and therefore have little effect on the coast north of Point Conception. III. SPECIFIC WAVE PRODUCING SITUATIONS The most important weather patterns with respect to the generation of high waves along the West Coast of the United States are discussed in the following paragraphs. A. EXTRATROPICAL CYCLONE 1. Cyclogenesis near the Coast: Very often, the most severe winter storms intensify rapidly in the immediate vicinity of the coast. This undoubtedly is the most serious problem the wave fore- caster must face. He must be able to predict the intensity and movement of the storm. A mistake of only a few millibars in pressure, or a slight error in wind velocity may prove disastrous to the client, for very high seas develop in a relatively short period of time. Fifty knot winds, for example will produce 25 to 30 foot seas in only a nine hour duration. A typical example of such a problematic weather pattern occurred last December. Referring to Figure 2, on December 26 at 0400 Pacific Standard Time a weakening low pressure center was located off the Washington coast. Winds in the vicinity of the Columbia River entrance were south 10 to 20 knots, and the swells were 8 to 10 feet from the west. A second weak low with a trailing polar front was located about 700 miles southwest of the first low. The position and strength of the high 214 * - ~ ~ ~~ z~ a'~ ~ ~ ~~~~~~~~o FIGU~z 6 D over the Aleutians feeding very cold air southward in- dicated the possibility of a rapid intensification of this low. By late afternoon of the 26th, the low had moved east-northeast about 600 miles and the winds along the coast were beginning to increase. The map of 0400 Pacific Standard Time 27 December is shown in Figure 3. The low at this time is just off the Northern Oregon coast, having moved east-northeast at a speed of over 40 knots and having intensified 25 millibars in 24 hours. Maximum winds occurred about three hours later with southerly winds off the Columbia River reported as gusting to 120 miles per hour. Wave heights exceeding 50 feet were observed for many hours. Owing to the very rapid movement of this particular storm, the winds in the cold air behind the front have not blown over a single stretch of ocean (fetch) long enough to generate significantly high waves. The forecast problem in this case is one of predicting the wind field (i.e., velocity, fetch, duration) preceding the front at the forecast site--in this case off the Oregon coast. 2. Cyclogenesis in mid-Pacific: Another type of storm which presents a completely different problem for the Pacific Coast forecaster is illustrated in Figure 4. Here, a series of very intense storms has been developing north of the Hawaiian Islands and moving northeastward to the Gulf of Alaska. Two deep lows already are present with a third low just beginning to intensify near 25 North, 170 West. For a forecast point off Vancouver Island, the forecaster must consider three main wave generating areas: (a) SSE wind area preceding the occluded front off Vancouver Island; (b) SSW wind area behind this front; (c) SW wind area behind the warm front (near 145 West), which is predicted to move northeastward. Another most important factor to consider is the in- creasing southeast wind field preceding the latter front. Clearly, the resulting sea state is very complex, with wave directions ranging from southeast to southwest, periods ranging from 6 to 16 seconds, and heights from 25-40 feet. The highest breakers along the Southern California coast are produced by storms of this type. Here, waves generated in the strong westerly wind fetch north of the Hawaiian Islands, travel eastward, reaching the coast in two to three days. Swells in deep water just off the coast normally range from 8 to 12 feet in height. Owing to the great decay distance, the period of these waves is quite long (14 to 16 seconds) whence shoaling factors are correspondingly high, and breakers of 15 feet or more occur at many Southern California locations. About once every two years this swell condition occurs simultaneously with exceptionally high astronomical tides; when this happens, considerable damage occurs to shoreline structures which have been built without due regard to the oceanographic environment (Figure 5). One of the more severe storms on record, with respect to high westerly swells off Northern and Central California, 216 N- w -3 '4'> *iis (>n I- .7 '4 4-A,~~~~~~ ./ .........l / / AL*Jr~~~~~~~~~~~~~~~~~~ A~ ~ ~~~~~~~~~~~~~~~ls FIGURE 5 STORM WAVES AT REDONDO BEACH FEBRUARY 23, 1949 occurred during February 1960. This storm began to in- tensify north of the Hawaiian Islands on February 6, and is shown in Figure 6 at 1600 Pacific Standard Time February 8, the day preceding the highest waves. Note the exceptionally strong westerly wind fetch area be- tween 125 West and 140�West. Normally, such intense storms as this will move into the Gulf of Alaska with the strong westerly winds remaining well off the coast. In this case, however, the westerly fetch area moved directly onto the California coast. The Coast Guard Cutter, U.S.S.Taney is shown in Figure 7, a few miles west of the Golden Gate on February 9. The 16-foot freeboard of this ship would indicate the hindcast significant wave height of 33 feet to be relatively accurate. These extreme wave conditions lasted for more than 24 hours. Again the necessity of an accurate weather forecast is evident, for had this storm moved to the northeast and remained 500 miles offshore, as is often the case, the wave heights along the coast would have been 15 feet. B. PACIFIC ANTICYCLONE Under certain conditions, very high seas are generated by strong north to northwest winds which develop on the east side of the Pacific high. This event is particularly common off California during spring and summer. Because the dominant wave direction is very nearly parallel to the coast, however, severe waves, with local exceptions, occur only in deep water. There are two weather patterns which are of great importance in this regard: (1) Nevada Low; (2) California Thermal Trough. (1) Nevada Low: Frequently, particularly during spring, large cold air masses aloft move from Western Canada and Alaska south eastward into Utah, Nevada, and Arizona. Cyclogenesis occurs on the surface, with deep low pressure areas usually forming in the area of Southern Nevada. In coordination with the Pacific high which is located but a few hundred miles offshore, this low produces a very tight pressure gradient along the California coast. Winds are further intensified as the core of maximum winds in the jet stream moves south eastward around the low. (2) California Thermal Trough: During the summer, with intense heating occurring over the Mojave Desert and San Joaquin Valley of California, a thermal low pressure area develops which, depending upon its intensity, may extend northward from Southern to Northern California and sometimes into Oregon and Washington. The interplay between this trough and the Pacific high is of utmost importance in the forecast- ing of northwest waves. Frequently, for example, troughs in the upper air flow will move into California, and the sum effect is to shift the thermal trough eastward, producing very strong northwest winds (up to 60-70 mile] per hour in spots) in the Point Conception area. Then, 220 -A ba~~~~~~~~~~~~~~~v > .20~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\ Figure 7 STORM WAVES OFF SAN~ FRAN- CISCO, Feb. 1960 CR 37 3 ft) 222 as the thermal trough re-develops in the San Joaquin Valley, the strong northwest wind-field gradually shifts northward. An example of strong winds off the San Francisco Bay area shifting to Northern California is shown in Figure 8. Winds reported by a client located off Bodega Bay, latitude 38.250Not on the afternoon of September 20, 1964, were northwest 50 to 60 with gusts to 83 miles per hour. Seas were reported to be 22 to 32 feet. The following day, winds were down to northwest 10 to 20 miles per hour and the seas 10 to 12 feet. Although winds and seas of this magnitude do not occur often under thermal trough conditions, winds of 40 to 50 miles per hour and seas of 15 to 20 feet are quite frequent (several per year). This is a good example of the type of forecast which exists so often: a very subtle, difficult to detect change in the weather pattern, will result in vast differences in wave and wind predictions. C. TROPICAL STORM WAVES IN SOUTHERN CALIFORNIA From May to October, Southern California often experiences swells arriving from a bearing between south-southeast and south-southwest. These waves appear to have two sources: (1) Extratropical cyclones of the Southern Hemisphere; (2) Tropical cyclones moving along the west coast of Central America. Swells from the former are characterized by very low heights (usually less than 2 feet high in deep water) and long periods (16-20 seconds). Waves from tropical cyclones, however, though normally having a decay distance of 700 to 1200 miles, sometimes reach heights of 5 to 10 feet in deep water off Southern California. Periods range from 10 to 15 seconds. In recent years tropical storm waves occurred about 4 to S times per season. Available records indicate that only three of these storms actually reached Southern California between 1895 and 1965. One of these, the hurricane of September 24/25, 1939, was of sufficient intensity to cause severe damage and considerable loss of life. This is, in fact, the most severe storm on which records are available for this area and has therefore been the subject of several investigations to determine design criteria for offshore structures. Due mostly to lack of offshore wind data, there is great divergence of opinion as to the actual wave height. However a significant height of 20 to 25 feet and period of 9 to 11 seconds appears reasonable (deep water). This storm struck suddenly without warning, a situation which is not likely to recur, for satellite pictures now are of invaluable assistance in detecting these storms, and reconnaissance aircraft are dispatched once the storm is deemed a threat to the U. S. mainland. D. LOCAL.SEA AND SWELL CONDITIONS A knowledge of local conditions, both with respect to weather and offshore topography is of extreme importance in wave forecasting. The Santa Barbara Channel, partially due to the east-west orientation of the coastline is an interesting study area of unusual local conditions. Three examples follow: two pertaining to local weather patterns, and one to offshore topography. 223 11(1 /~17 H A ~~~AI Nj 7,/I Bell I~~ A IA I/ J2 TI URI~I 69 2 2 S ept' 11964 o0 O 22~~~~4. 1. Northwest Winds off Point Conception: Wave trains in a generating area exhibit a complex pattern of short-crested waves which contain components of considerable height traveling not only in the wind direction but also in directions at variance with the wind. When wave trains under a generating wind are inter- rupted by islands or headlands, as in this case, the variable direction of wave travel with respect to the generating wind becomes of prime importance. Consequently, the Santa Barbara coastline, though sheltered from north- west swell (being more unidirectional in nature), is exposed to northwest seas generated off Point Conception. Strong northwesterly winds in this area are common, and result from several different weather situations, the Nevada Low being one. Another example of a very local problem occurs under certain conditions when an upper trough is located just off the coast, rather than inland. In such cases, winds aloft blow from the southwest at heights above 5000 feet and blow from the northwest be- low 5000 feet. The relevant surface map shows high pressure offshore, with the usual eddy low circulation east of San Nicolas Island. Thickness differences for the 1000-850 millibar levels between Vandenburg Air Force Base and San Nicolas Island are 100 feet or more, with the shallower, dense layer lying to the north. As an example, a meso-scale surface analysis for 0700 Pacific Standard Time, August 21, 1961 is shown in Figure 9. For this situation, wind gusts up to 60 miles per hour were reported below the coastal canyons just east of Point Conception along with 8 to 10 foot swells in the lower channel. However, winds in the Santa Barbara area, just 30 miles to the east blew from the southeast to southwest at only 5 to 10 miles per hour. Winds and seas decreased rapidly once the upper trough moved inland. 2. Santa Ana Condition: During the winter, strong high pressure areas frequently move southward from Canada into the Great Basin. Very cold air then spills to lower elevations, warming adiabatically and producing exceptionally strong north- easterly winds below the major coastal canyons of Southern California. The Santa Clara River Valley is particularly susceptible to such conditions, with northeast winds gusting to as much as 80 miles per hour upon entering the Santa Barbara Channel near Ventura. Because of angular dispersion in the wind and wave field, east-southeast waves then move up the channel and sometimes are as much as 8 to 10 feet in height in the Point Conception area. An example of this weather pattern is shown in Figure 10. 3. Wave Refraction at Ventura Harbor: When a wave travels from deep into shallow water, a change in its height, length, and direction of travel occurs, be- cause of bottom topography. A long-crested wave approach- ing a given shoreline at an angle is bent, or refracted, from its original direction because the inshore portion of the wave "feels" bottom first and travels at a lesser speed 225 ilAg 6 ll\(OZ~~~~~~~~~~1 t-4 ~ ~ ~ ~ ~ ~ ~ ~ ~ A FIGU 10 Dee~~~~~~~~~~~~~~~~~~~~~~~~~ 16~~~~~~~~~~~~~~~~~~~' than does the deep water portion; this differential effect causes the wave crest to re-orient and become parallel (more or less) to the bottom contours. In the case of a submarine ridge, waves bend inward on either side of the ridge thus causing a focusing effect of wave energy; the opposite holds for a submarine canyon. Such a submarine ridge exists immediately west of the Ventura Marina, in the middle of the Santa Barbara Channel coast. Here, waves approaching from the west to west- northwest, having periods of 12 seconds or more, converge in the immediate vicinity of the harbor entrance. On frequent occasions high breaking waves cover the entire entrance (many yachtsmen have been known to take up surfing), yet 1000 feet on either side, the waves are low. IV. MAJOR PROBLEMS FACING THE PACIFIC COAST WAVE FORECASTER Clearly, the ability to produce a good wave forecast is an art; it is based on technical skill and experience, but above all upon a reliable meteorological input and an ability to communicate with the user. This latter aspect is of para- mount importance, meaning both message transmission in the usual context and content transmission in the sense of pro- viding data for a given marine operation in a language that is clearly understood by the user. Thus, not only must the message be received by the client physically, but even more, it must be presented and interpreted correctly. In general, communication problems are common to all forecasters, irrespective of location. That is, problems associated with phone systems, radio links, telegrams, etc. differ little be- tween the Pacific, Atlantic, and Gulf Coasts of the United States. On the other hand, methods of presenting and inter- preting wave forecasts are very closely related to the complexity of the wave climate; the more complex the wave climate, the more difficult the communication or interpretation. In this respect, the Pacific Coast forecast is unusually complicated, primarily due to the fact that at any given time, waves existing at a given location often are a composite of several wave trains--each with a distinctive direction, height and frequency spectrum. Specifically, it is not uncommon for three to five distinct effective wave generation areas to exist simultaneously in the eastern North Pacific. The interaction of these varied inputs on a given marine operation is not always obvious, let alone possible to forecast. Thus, adding several sets of wave energies and specifying the correct resultant for a moored drilling vessel that is highly sensitive to wave impulses from more than one direction, is not a simple matter. The problems in terms of resonance are obvious. Here, the forecaster must know each vessel's characteristics so that he can emphasize those wave conditions of main importance. In view of the large spectral ranges possible in the Pacific, the forecaster has a constant "filtering" task to perform. Many marine operations are sensitive to multi-direction effects and many are not; many operations are endangered only when wave heights are very large and of sustained duration. Many shallow water operations such as inshore coring, and drilling, dredging, shoreline construction and small craft launching become susceptible to waves of relatively low deep water height and which in actuality were generated by large "off the map" 228 storms located several thousand miles away from the Pacific Coast, including the South Pacific Ocean, because of their shoaling enhancement. This is not to say that Pacific Coast wave conditions are mild; on the contrary, winter storms producing 30 to 40 foot high waves are as common off the Oregon-Washington coasts as are winter snow storms in the Midwest. Above all, however, the fundamental problem facing the Pacific Coast wave forecaster is that of obtaining an adequate meteorological input upon which to make a wave forecast. In this respect the Pacific Ocean is a veritable Siberia in data coverage as compared with the North Atlantic and the Gulf of Mexico. When one compares the basic meteorological data input available for making forecasts in the three U. S. Coasts, he finds that the data density of the Pacific weather control regions normally is about one percent of the densities of the Atlantic and Gulf control regions. When severe storm conditions arise in the Gulf or the Atlantic, numerous special aircraft flights into the storm are made, and extra ship observations are procured as a matter of course; in the Pacific, on the other hand, if anything, ships and aircraft bypass severe storms or cyclogenesis areas, thus actually diminishing data density in time of need to the Pacific Coastal areas. In short, when the need for meteorological data is at its greatest, the data density in the Pacific goes from the ridiculous to the absurd. As an illustration of the data density problem, Figures 2 and 3 show the weather pattern and data coverage for the "not-unusual" storm of December, 1965. As can be seen only four ship reports were available in an area outlining the storm between 34 North and 55 North and from the coast to 150�West. Of these four reports, one had its position in- correctly coded. Clearly, the task of accurately predicting the wave conditions produced on the Oregon-Washington coastal areas, by this storm, was, to say the least, most difficult. The reasons for data density differences of the Pacific, Atlantic and Gulf regions are clear and logical. That is, the heavy meteorological station density in the weather control regions of the Atlantic and Gulf are consequences of natural storm tracks, population distribution, and ship traffic. Under any circumstances, the task of providing truly accurate wave forecasts for locations along the Pacific Coast is made very difficult if not impossible by the lack of a reliable meteorological input. There is no simple cure to this problem since it is not likely that ship routes and seamanship practices will change materially in the next few decades, or that the density of ship traffic will increase very much. Probably the most reasonable solution to the data density problem involves the installation of weather buoys at the rate of one buoy per, say, five degree square throughout the Eastern Pacific. This is a task which will be both extremely expensive and difficult to conduct, and which, though justifiable, is not likely to be funded for some time to come. Satellite weather pick-up while interesting, is not likely to improve the picture for detailed forecasting. 229 DRILLING IN THE SEA FROM FLOATING PLATFORMS By N. E. Montgomery Abstract Credit for much of the early development of floating drilling goes back to the CUSS Group. This Group. composed of members of Continental, Union, Shell and Superior Oil Companies, was formed to study the application of offshore drilling for the West Coast. Using a converted Navy ship the Group in 1953 drilled several experimental wells while moored in sheltered waters. Since that time, many wells have been drilled through- out the world from floating rigs of various designs. In 1962, Shell Oil Company drilled the first well from a floating platform with the well head and equipment location on the ocean floor in more than 250 feet of water. In 1964, Shell drilled in 574 feet of water off the West Coast using a floating semi-submersible rig. This paper will describe in general the steps followed in drilling a well from a floating rig beginning with the moving on a location through the abandonment. Brief discussions are offered on the selection and application of the equipment necessary for drilling as well as the problem of stability, maintaining the rig on location and the requirements for specially trained personnel. Weather is perhaps the single most important factor opposing the success of floating drilling. Its effect on the operations conducted on the West Coast will be discussed. It is concluded that the floating platform has been successfully employed as an effective means for the exploring of oil and gas in deep water throughout the world. DEVELOPMENT OF FLOATING PLATFORM The search for oil has lead man from the hills and plains, into the marshlands toward the sea and finally into the open waters throughout the world. Why this quest for oil in water depths too deep for divers and where such things as sub- marines and robots may become a standard member of the drilling crew? The answer is simple. The sea holds the greatest attraction to the oil man for continuing the search for oil. It is estimated that more than 70% of the earth's surface is covered by water, but that 90% of the world's oil supply presently comes from the land. In the early 1930s marine drilling was born when the oil derricks and drilling equipment were added to barges and floated into the bayous and marshlands of Louisiana and Texas. Once on location in about 6 feet of water the barges were sunk to set on bottom and drilling proceeded. It was not until 1938 that the first producing well was drilled in the waters off the Louisiana coast. Since that time many offshore leases have been drilled both in state and federal waters, in the Gulf of Mexico and off the Pacific Coast as well as in many other parts of the world. Rigs used to drill these leases have varied in design and increased in size. Today it is estimated that more than 125 mobile and floating rigs are operating in waters throughout the world as well as some 90 tenders and platform rigs. 230 In 1948 a four party group of oil companies was formed in California to conduct offshore exploration including the study of offshore drilling techniques. The combine, called the CUSS group, was composed of the Continental, Union, Superior and Shell oil companies. This group, as well as other operators, had actively engaged in recovering core sampled from the ocean floor by means of jet and drop dart sampling devices. In 1953 the first conventional rotary drilling rig was mounted on a small ship called the "Submarex" and floating drilling was born. The Submarex, shown in Figure 1, was a 173 foot long x 23 foot beam former navy patrol boat which was converted for use as a drilling ship, with its mast mounted over the side. The next four years, from 1953 to 1957 saw several floating rigs in service both in the waters off Southern California and in the Gulf. Most of these rigs were either converted barges, tankers or former navy landing crafts. In 1956 the CUSS group built the CUSS I. This vessel, a converted YFNB barge, was 260 feet long and 48 feet across the beam. A 98 foot derrick was mounted in the center of the ship and drilling was conducted through an opening extending through the hull which somehow became known as the "moon-pool". This arrangement gave greater stability than the rigs with the derricks mounted "over-the-side". In 1961 the CUSS I was selected to drill the first test holes for the Mohole Project sponsored by the National Science Foundation. The rig was outfitted with four - 250 H.P. "Harbormaster" outboard motors for positioning and successfully cored in 11,672 feet of water off the coast of Guadalupe Island. This is the deepest water to date that any rig has operated in, however, wellhead equipment was not used and the system lacked the capability of re-entering the well once the drill string was pulled. The rig also holds the record for having drilled in waters of 632 feet, the deepest yet while using conventional wellhead equipment located on the ocean floor. During the years from 1955 to 1960, oil and equipment companies were busy developing techniques and equipment for drilling and completing wells in water depths of up to 1000 feet. In 1960 Shell completed perhaps the first oil well in the world with all the well control equipment, wellhead and christmas tree placed on the sea floor without the use of divers. Concurrent with equipment and technique development, investigations were conducted to determine the best design for a floating drilling vessel. It was concluded that while the ship-shape hull rigs were quite stable in protected waters, on areas wherein the direction of the seas was fixed, more or less, they would be less effective in waters wherein direction of seas shifted rapidly such as the open seas of the Pacific and the Gulf. After much investigation and model testing, the use of a semi- submersible rig was decided upon. Such a design appeared to offer the lease average resistance to wind, wave and current as these forces rotated about the rig. A number of these rigs, like the Bluewater No. 1, (Figure 2) were already in operation in the Gulf, where they were being used to drill while sitting on bottom in water depths of up to 90 feet. The merits of modifying one of the existing mobile rigs were considered and weighed against the cost and time delay of constructing a floating rig of a Shell design. It was decided to convert the Blue Water No. 1 rig, in conjunction with Blue Water Drilling Corporation, to become the first floating drilling platform. 231 I 1, C.,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Ki~~~~~~~~~~~~~~~~~~~~~~~~~~~~J' w~~ 4-~i i i~;--ii::_ if-i !? I��~ i~!i~' r i�~~ ~~ ~i i! ~l F~~~~~~~~~~~~~~~~~~i gur 2:: 233~~~~~~~~~Mi� Two of the factors which Influenced this decision were the federal lease sales of 1960 and 1962. Leases in water depth of from 240 to 300 feet in the Gulf of Mexico had been obtained by Shell in 1960. With another federal sale scheduled for March Of 1962 Shell decided to evaluate these leases using a converted rig rather than building a new rig in order to save time and money. The conversion cost about $1.5 million and included the addition of automatic ballasting controls, an eight line mooring system and special handling equipment which would be needed in running the underwater equipment. The first well drilled from a floating platform was spudded in January, 1962. It was only a matter of time before the industry would be pushing into deeper and deeper waters. Whether or not the successful demonstration by Shell of the capability to drill floating in waters of almost 300 feet had any influence on this timing, it is hard to say, but at the March, 1962, federal lease sale off Louisiana and Texas, some 1,958,000 acres were leased to 30 different oil companies. Of this total about 820,000 acres lie in 100 - 200 feet of water, 213,800 acres lie in 200 - 300 feet of water and some 37,000 acres were located in waters of 300 - 600 feet deep. All of these leases had a 5 year primary term in which to establish production. Since there were only six bottom supported rigs in existence that could drill in more than 100 feet of water, there followed a sudden surge in the construction and conversion of rigs for use as floaters. At the time of the March, 1962) lease sale there were only 12 floating drilling rigs of any type existing in the world. At the present time there are approximately 50 floating rigs of various designs, either available or under construction throughout the world. At the first federal lease sale ever held on the Pacific Coast in May of 1963, 58 tracts containing 312,974 acres were sold to only 4 oil companies at a cost of $12,807,837. Of these 58 tracts Shell Oil Company obtained 49 containing roughly 267,000 acres, at a cost of $11,440,000. Figure 3 shows the location of the federal leases obtained in 1963 along the California coast. In the fall of that same year Shell used the CUSS I to drill a well in 240 feet of water off Point Reyes, California near San Francisco. Because of the severe weather conditions that exist at Point Reyes, the CUSS I was replaced by a larger rig, the GLOMAR II and the well was successfully completed. However, severe storms continued to hamper the operations and the attempts to drill the second well were unsuccessful and operations were suspended in January, 1964. Earlier in 1963, in anticipation of such weather, and future sales off Oregoni and Washington where the weather wa6 expected to be worse, Shell had contracted with Blue Water Drilling Corporation for the construction of the Blue Water No. 2. This rig would be the first floating platform to be constructed and used on the West Coast; thus Shell's requirements for a large and relatively stable rig that could operate efficiently year round in the hostile weather and sea environment was expected to be fulfilled. The Blue Water No. 2 rig (Figure 4) which is now owned by Santa Fe Drilling Company, was built by Kaiser Steel Company, Richmond, California. It was launched in July of 1964 and towed to location off Point Reyes, California, near the site of Shell's 1963 drilling ventures. 234 OREGON CAtIFORNIA CRElSCENT CALIFORNIA OFFSHORE CITY FEDERAL LEASE LAND MAP o SO 100 150 I , ~ ~,o ,o SCALE IN MILES EUREKA 0 Figure 3 235 MOTEREY Figure 3 235 BLUE WATER NO. 2 PT. REYES AREA Figure 4 236 The rig, which has a displacement of 9,400 tons, is square, measuring 204 feet 8 inches outside the lower 14 foot diameter horizontal tubular hull. The main deck, located 68 feet 6 inches above the hull, is 188 feet x 188 feet with the 142 foot derrick mounted in the center. The main deck is supported by four 24 foot 8 inch diameter corner columns and twenty-five 42 inch diameter support columns. Living quarters provide facilities for 52 men. Several special features were incorporated into the rig construction in anticipation of the drilling needs. A work deck, or spider deck, was located 47 feet below the drilling floor for use in handling and storage of the underwater equipment. A special building and handling facilities were added to house a robot which was to be used in the drilling operations. A counter- weight system capable of exerting 200,000 pounds of vertical force was installed to provide variable tensioning capabilities for supporting the marine conductor; and a marine control room was constructed to accommodate the automatic ballasting controls radar, and the many devices used in measuring and recording weather and the vessel's motion. The rig is equipped with an emergency general alarm system, necessary navigation lights, three 20-man inflatable life rafts, fire fighting gear, life jackets, Life rings and a hospital room. Power for the rig is supplied by three General Motors, E.M.D. units which develop 4350 H.P. to drive 6 DC generators. These in turn furnish power to 9 motors at the various drilling equipment stations. AC power is furnished by two 625 KVA generators and one 150 KW, AC diesel generator for emergency use. The first well, using the Blue Water No. 2 rig, was spudded on August 2, 1964, in 438 feet of water. Cost of this first well was $96 per foot compared to $300 per foot for the first well drilled nearby with the ship-shape vessel. Subsequent wells drilled in the general vicinity averaged about $60 per foot, some of which were drilled during the winter season of 1964-1965. The rig was used to drill 10 wells off the California coast between August, 1964, and July, 1965. The maximum water depth was 574 feet near Crescent City, California. The deepest depth reached was approximately 10,600 feet. In October of 1964 the first Federal lease sale off Oregon and Washington was held. The interest in leases was much higher from an industry viewpoint than what it had been off California in 1963, when only four companies were successful. The 101 leases were sold to 11 companies for a total of some $35,500,000. Of the total leases, 74 were located off Oregon and 27 off Washington and averaged about 5600 acres each. Water depths varied from 200 to 1300 feet, as shown in Figure 5. In July, 1965, the Blue Water rig was moved from California to a location near Newport, Oregon, where two wells were drilled. The rig was later moved to a spot off the Oregon coast, south west of Astoria about 35 miles, in October, 1965. Here the rig remained throughout the winter and drilled only one hole between November, 1965, and March, 1966. Only two other wells have been drilled in the Federal waters of either Oregon or Washington by Standard Oil Company et al using the WODECO III. The rig worked throughout the summer and returned to California in October, 1965. 237 VANCOUVER ISLAND CAPE/'__, FL TS~~,nw \pj ~HOH HEAD SEATTLE GRAYS HARBOR WASHINGTON TILLAMOOK ORTLAND NEWPORT OREGON *EUGENE /~~~ WASH.-ORE. OFFSHORE FEDERAL LEASE LAND MAP 0 50 100 ISO SCALE IN MILES Figure 5 238 OPERATIONS OF A FLOATING PLATFORM To describe the operation from a floating rig, a brief discussion of the step by step procedure used in connection with the Blue Water No. 2 operations follows. Moving and Positioning On Location The rig is towed between locations by either three or four tugs. Generally, 3 tugs of about 1500 H.P. each are used for short moves and 4 tugs for long moves Average speed for all moves has been about 2 knots. To date, only 8.5% of the total time has been spent moving which also includes the weather down time during the move. To position the rig at the desired location requires one of two methods; either by precalculated distances measured to a point of intersection using conventional visual survey instruments. Because of distances from shore, visibility, and prevailing weather conditions the rig has most often been positioned by use of electronic equipment, such as SHORAN. The accuracy of the method varies between 50 and 200 feet. The method provides continuous tracking of the rig and "instant plotting" of its position as well as the position of all anchors. Electronic gear is available both on the rig and the anchor handling boat. Once the rig is anchored, the position is checked using conventional equipment requiring a greater time- lapse between the observations and final results. After the location is checked the rig is ballasted to drilling draft of about 38 feet and all eight of the 22,000 pound anchors are tested. Drilling operations can then begin. Spudding Once the rig is at drilling draft a measurement is made of the water depth. Next, 150 feet of 24" conductor pipe are attached to a pile Joint and landing base for running. The pile joint is connected by way of the 13-3/8 casing head to the blow- out preventers. The assembly is tested and sufficient lengths of 16" non-buoyant marine conductor are then attached to the top of the B.O.P. stack and the entire system is lowered to within 20 feet of the ocean bottom. Hydraulic control of the B.O.P. stack is accomplished through a multiple conduit hose bundle attached to the marine conductor and extending between the stack and the rig. The marine conductor is suspended on the spider deck below the drilling floor. The drilling string, usually consisting of a 12-1/4" bit and a 28" expandable hole opener, is run through the assembly and a 28" hole is drilled to about 250 feet below the ocean floor. When the hole is completed, the drill pipe is raised 150' leaving approximately 100 feet of pipe in contact with the hole. The lower portion of the drill pipe is hung off inside the marine conductor by means of a special landing sub and the upper portion removed. Additional lengths of marine conductor and the slip Joint are then attached and the entire assembly lowered until the landing base rests on bottom. During this operation the proper amount of counterweights are attached to the slip-Joint so as to provide proper tensioning to the system. Once the landing-base is on bottom the spudding string is removed and open ended drill pipe is run in to cement the conductor pipe. 239 Figure 6 240 The kill and choke lines are run and subsequently tested together with the B.O.P.s. A i2-i/4I" bit is then run to drill below the conductor pipe for setting surface casing (see Figure 7). This string usually consists of about 2,500 feet of' 9-5/8" casing. The casing is made up to a hanger and run on drill pipe and seated below the B.O.P. inside the 13-3/811 casing head. The Robot can be used to lock the hanger in place or slips can be set if need be. Shell's robot (shown In figures 8 and 9) is an integral part of the deepwater operation. The unit has two TV cameras, a sonar for locating equipment underwater, a gyro-compass for direction, and two electrically operated propellers for swimming. A hydraulically operated socket wrench is also mounted on the unit for operating the various valves and lock screws mounted on the B.O.P. stack. The casing running string is then pulled and open ended drill pipe is run to within 200 feet above the float shoe and the 9-5/8" casing cemented back to the ocean floor. After the cement has set and the B.O.P. assembly has again been tested an 8-3/4" hole is drilled to total depth. If conditions warrant, either a 5-1/2" or 7" casing string could be run. One feature of the system currently used by Shell on the Pacific Coast is that there are no guide lines between the rig and the equipment on the ocean floor. Once the landing base is landed, the kill and choke lines are guided into place by tracks along the marine conductor. A hydraulic hose bundle attached to the marine conductor operates the B.O.P. stack on bottom from controls located on the rig floor. Since all casing strings can be run inside the 16" marine conductor and the B.O.P. there is no need for guide lines. In the event it becomes necessary to view the wellhead, B.O.P., or marine conductor, the robot is used. It can swim freely and locate the assembly with the aid of its TV and sonar. A number of wells have been drilled without the robot making any such dives at all. In cases of bad weather, the control valves on the well can be closed and the marine conductor can be released from the top of the B.O.P. stack to prevent damage to the equipment or the rig. To re-establish contact with the B.O.P. the robot is used, first to locate the stack, and then by use of the T.V. to afford the drilling personnel visual contact to re- attach the marine conductor to the stack. This operation has been successfully carried out numerous times in the waters off Oregon. There is little to distinguish the normal routine drilling operations on a floating platform from that of any other platform. Round trips of the drill pipe to change bits are the same. Mud is circulated in the same manner and the B.O.P.s are operated in the usual way. When the total depth has been reached the well is logged using standard tools and after making necessary evaluations the well is abandoned. Abandonment In accordance with the U.S.G.S. requirements on the West Coast. the equipment must be removed to 3 feet below the ocean floor when the well is abandoned. In compliance with these 241 ---l-in r'1 Figur--e 7 242 Figure 8 243 ON i I ffmffmmm - k- ,I, a, I i T , "I 1 Figure 9 244 regulations the necessary cement plugs are set in the hole and all the casing strings are cut, using a mechanical cutter, at a depth of 20 feet below the ocean floor. Designed into the 24" pile joint is a shear joint which will separate at a total combined force of 600,000 pounds of pull and hydraulic pressure. The B.O.P. stack, wellhead and landing base are then retrieved leaving the location clear and the pipe removed to about 4 feet below the ocean floor. Once the equipment has all been retrieved, the rig is deballasted and the anchors retrieved to start towing to another location. Performance The rig has performed satisfactorily as expected. During the period from July, 1964, through March, 1966, the rig has drilled 13 wells, including one directional hole. Total down time due to weather during the period totalled 9.3%. A breakdown of the weather effect during moving and while anchored is shown in Figure 10. "At-anchor" down time due to weather has been only 7.9 per cent with most of this occurring on the last well in Oregon. High seas, strong unforecasted winds, and anchor problems on this well account for the delays. It is estimated that ship-shape vessels operating in this environment would have been shut down a substantially greater percentage of the time than the more stable rigs of the semi-submersible type. This conclusion has been reached after spending one winter in the Oregon waters. Much of the down time results in preparing for forecasted bad weatherand recovering operations after the storms. The rig has conducted drilling operations in 25 foot seas, but since there is always the possibility of anchors slipping, precautions must be taken in this event to safeguard men and equipment. Thus, even though a large stable rig may not have the motion of a smaller rig or ship-shape vessel, it is subjected to large forces resulting from the wind, sea and current, and could still move off location. Furthermore, during periods of bad weather it is increasingly difficult to transport needed men and materials and safely unload them onto the rig. Figure 11 shows the actual winds and seas encountered while drilling off Astoria, Oregon, from the last of October, 1965, through the end of February, 1966. It is interesting to note that for a 72 day period between October 21 and December 31 the seas were 10 feet or greater approximately 52 days, or roughly 72% of the time. Weather Weather and its effect on the operations continues to be one of the most important obstacles confronting floating drilling. This is even more true in the Pacific northwest than in other areas such as the Gulf of Mexico. Most winter storms develop in the vicinity of the Gulf of Alaska and since there are few weather data reporting points available to the forecasters these storms are hard to track and difficult to forecast. In addition, the local topography of nearby mountain ranges often result in considerable variations in wind intensity. Such conditions have on numerous occasions resulted in winds exceeding hurricane force (75 mph) and on one occasion gusts of 105 mph were recorded on the rig while on the shore, some 35 miles away, the anemometer blew away at 120 mph. Because such conditions can arise without much notice, a weather bill is furnished the operating personnel on board the rig. This bill outlines the necessary steps to be followed in case of such storms. Briefly, the bill provides that at any time 245 EFFECT OF WEATHER UPON BLUE WATER 2 OPERATIONS Month Moving - Hours on Location - Hours Location Spudded Total Hrs W.O.W.* % W.OW. Total W.O.W. %,W.O.W. 1. California Aug. '64 48 0 0 1,600 16.8 1 2. " Oct. '64 262 157 60 648 16.8 2.6 3. Nov. '64 43 0 0 305 0 4. " Dec. '64 168 76 45.6 624 48 7.7 5. " Jan. '65 84 32.6 39 636 120 18.8 6 ". - Sidetrack hole 259 0 7. " Feb. '65 72 12 17 403 0 8. Mar. '65 107 11 10.3 2,245 91 4.0 9. " June '65 171 35-1/2 20.8 552 22.2 4 10. " July '65 41 0 0 481 0 0 11. Oregon Aug. '65 111 0 0 481 0 0 12. " Aug. '65 31 0 0 1,307 36 2.8 13. " Oct. '65 5.2 0 0 3,240 660 20.4 Up to 3/8/66 TOTAL 1,203 324 27 12,781 1,011 7.9 OVER-ALL % 13,984 1,335 9.5 (Moving & on location) * W.O.W. = Waiting on Weather FIGURE 10 100 100 90 90 80 so WIND 70 70 60 IIII60 50- 50 4~~~~~~~~~~~~~~~~~~~~~~~~~~~0 4 ~~~~~ILAIAMCD ~~~~~~~~~~~~~~~~~~~~~~~~20 0 m 253w S2 53 5 lo 25 0 5 0 5 20 25 UP~ 5 10 1520 50 OCT NOV DEC. JAN. FEB. Z 1965 1966 40 IISEAS 4 30 30 H ii, i1'' lo .,U ]kll2 20 30 5 0c 15 20 2 30 5 0 5 20 25 3 5 to S1 5 2 0 5 a0 1 20 25 OCT. Nov. DEC. JAN. FEB. 1965 1966a winds of 50 mph or greater are reached or forecasted, steps must be taken to be able to release the marine conductor from the B.O.P. stack. This usually entails setting plugs in the well and closing the B.O.P. blind rams. This action has been taken numerous times during the past winter. On November 18, 1965, an unforecasted storm moved in over the area and because of localized conditions, winds of 93 mph were recorded. This storm resulted in the rig being moved off location and the marine conductor parted in two places. During the recovery period that followed several more storms reached the area. Figures 12 and 13 show the actual sea and wind conditions and the vessel motion that resulted from the storms of November 18, and December 27, 1965. As already stated earlier, because of the unpredicted weather and its resulting effect on the operations, every consideration must be given to the weather in order to safeguard men and equipment. Trained Personnel Required The need for better trained and higher caliber personnel for floating drilling is becoming more and more evident. The roustabout, who not too long ago was engaged in unloading supplies and chipping paint, among other duties, now finds it necessary to pass tests in fire fighting, first aid, and survival. In some cases he must also be able to make and understand the stability calculations made on the rig. The driller and his "roughnecks" must know and understand the working parts of everything he has run into the well. Once below the ocean waters it is hard to take another look or make some needed adjustment. They must also be constantly alert as to the effects the seas, weather or a particular operation will have on the rig, and must always be in communication with the barge supervisor on duty in the control room. The supervisor of such operations must be the best available. He not only must be thoroughly familiar with the various aspects of floating drilling and the equipment, but must also be able to make necessary decisions to assure safe and trouble free operations. The personnel working in floating drilling operations must be the best trained the industry can supply. Reasons For Floating Drilling The application of floating drilling warrants consider- ation in many situations, such as the following: 1. In the deeper water depths throughout the world. Platforms are being designed for waters of 400 feet, however, their installation will cost between $4 to $10 million and can not be justified until production is assured. 2. In areas where bottom conditions will not support platform. 3. In areas where platforms will present either a navigational or aesthetic problem. 4. For conducting exploratory drilling in areas where time is a factor and water depths can vary from 100 248 VESSEL MOVEMENT AND WIND AND SEA CONDITIONS DURING STORMS OF NOV. 18 AND DEC.27,1965 _PITCH 10 1fl ;7 1 1 I IPITCH I I I I I V tiOi I I I I I I ~ ~ I 2 el I I I I I I I I 21 I I P I T I I I I I I I :2 , ROLL 5ROLL w I I I I I sw3 I / I I I I f I~ 1 1 .DEVIATION FROM LOCATION o ADEVIATION FROM LOCATION 2 L -OUTIOF ORPjER -1 IV - Z zo ,HEAVE ,|~T-_iHEAVE lI IV I I I I I I \\\\ I I1 I i 1 A I I i I I t 16 I4 4 ILI I8 O U M E r I I\\\\\\VI I I 161 W I I I I I I I I I I 2 2 1 1 1 1 1 1 1 1 1 1 1 1 2 I I I I I I IIoI too00 100 5so .I ND 70WINC VELDCITY I /K 0~ ~I I_ /--- 1 70 60 rf 41' 40 30 =0 EO s50 I O I I= 5I IHT | 40 40 30 20 20 I0 0C II 6AM 12AM 6PM 12PM 6AM 12AM 6PM 6PM 12PM IM 12AM 6PM 12PM NOV. I *' NOV. 19 DEC.I 6 IDEC 27 Figure 12 249 NOV. I8*t--OV 9DC2 to 1300 feet such as along the Pacific Coast. One rig with its associated underwater drilling equipment is capable of covering this range. Future What the future will hold for the floating platform is hard to say. It can be expected that the next few years will see more and more of the wells completed on the ocean floor from the floating rigs. Such completions to date have been few,.since rigs have been engaged primarily in programs to evaluate quickly the large number of leases for possible platform drilling development. As the waters become deeper these completions will be made on bottom. They will also be made without divers' assistance and such tools as robots, sonars, and TV equipment will become common place. Most of the problems facing the floating driller today, namely, weather, anchoring and transportation will remain a concern regardless of water depth. However, one problem that becomes more serious as the water depth increases is that of designing a suitable marine conductor or a means of conducting the drilling fluids between the ocean floor and the rig. Anchors and anchor lines will give way to dynamic positioning and rigs may even be placed on the ocean floor. Conclusion The science and technological development of drilling in deeper and deeper waters is presently in advance of our economic justifications for doing so. However, the development and experience necessary to make it economical can not wait to begin the day it is justified. ACKNOWLEDGMENT The author wishes to thank Shell Oil Company for permission to prepare and present this paper. BIBLIOGRAPHY The primary references for this paper were the many excellent articles which have appeared over the years in the Oil and Gas Journal and the Offshore magazine. MARINE COMPLETION SYSTEMS Leonard E. Williams Cameron Iron Works, Inc. Abstract When the search for petroleum was first extended into the offshore areas, a conventional type rig with conventional equipment was used on a permanent platform, which in essence was a land operation on an artificial island. The mobile bottom supported platforms and the floating structures (vessels or platforms) were developed for more versatility. Accompanying the development of these rigs was the development of the mudline suspension and the subsea systems. The mobile bottom supported platforms can use either a mudline suspension or a subsea system. The floating structure uses only the complete subsea system. In the mudline suspension, the casing strings are landed with hangers at the mudline and the casing extended back to the surface where conventional blowout preventers and wellhead equipment are installed. The complete subsea system involves landing the casing strings at the mudline and Installing the wellhead and blowout preventers on the ocean floor. Usually this is done by hydraulic connectors, but it can be done by divers. With either system, when the well is to be completed, a tree can be installed on the ocean floor or the casing extended back to a platform and a conventional tree installed. DRILLING STRUCTURES Depending on the environmental conditions, offshore drilling may be done from any one of five structures. They are: I) the bottom supported rig, which is a platform or structure supported by the ocean floor during drilling operations. 2) the Jack-up rig, which is a bottom supported rig, is mounted on a floating hull. The Jack-up rig has movable legs that are raised for moving the rig, and lowered to the ocean floor to pick the rig up out of the water and support it during drilling operations. 3) the submersible rig is a bottom supported rig which Is also mounted on a floating hull. The submersible hull is pumped dry for moving the rig, but Is filled with water and sunk on the ocean floor for support during drilling operations. The bottom supported rig, the jack-up rig, and the submersible rig utilize the mudline suspension system. In the mudline system the casing strings are landed and suspended with hangers at the mudline (ocean floor), and the casing is extended back to the surface where conventional blowout preventers and wellhead equipment are Installed. 4) The semi-submersible rig -- a rig on a floating structure with a hull that can either be filled with water to set It on the ocean floor for support during drilling operations in shallow waters, or left dry with anchors to hold It in place during drilling operations In deeper waters. 5) the floating rig -- a rig on a vessel, barge, or floating structure that Is not supported by the ocean floor and is held In place by anchors while drilling. The second type of marine completion system Is the subsea system. The semi- submersible rig generally uses the subsea system, and the floating structure 251 always uses It. The complete subsea system involves landing the casing strings on the ocean floor, and installing the wellhead and blowout preventers there also. DRILLING OPERATIONS The following discussion will cover drilling operations from a floating rig. The complete subsea completion system will be described, with a casing program of 30" x 20" x 13-3/8" x 9-5/8" x 7" used for illustration. After moving on location, the first objective is to set the conductor pipe. The most common conductor pipe diameter is 30" ranging from 100 to 200 feet or more In length. There will be a casing head housing welded on the top and a guide base frame with guide posts mounted just below the casing head housing. The conductor casing is set for the following reasons: to prevent consolidated surface formations from sluffing into the well bore; to provide a landing shoulder for the next housing to be run; and to attach the guide frame, which is used as a means of guiding and alignment over the well bore. There are three methods of getting the conductor pipe down: I) Jetting 2) Driving 3) Drilling a hole in the ocean floor and then lowering the conductor on drill pipe Into the hole and cementing. When the hole is drilled for the 30" conductor, a guide template Is lowered into position on drill pipe to guide the conductor pipe In place. The template has two cables extending back to the surface and serves as a temporary guide first for the drill string and then for the conductor. A guide frame known as the Universal guide frame, is wrapped around the drill pipe just above the drill bit and guides the bit down along the guide cables to the ocean floor where a 36" hole is drilled. The Universal guide frame is retrieved on top of the bit. Next, the 30" conductor pipe is picked up and stood in the derrick in sections ranging from 50 to 60 feet. As the first section is lowered into the water, the Universal guide frame is wrapped around the 30" for guidance into the hole that has been drilled. Usually, one or two welds are required to make up the 30" into one section which is lowered to the second deck on drill pipe. At this level the wellhead guide structure (Fig. I) is attached to the 30", the guide lines installed to the posts of the wellhead guide structure, and the drill pipe is made up into the top of the 30". The 30" conductor Is then partially lowered. When the 30" enters the guide template, the Universal guide frame Is retrieved. Then the 30" is completely lowered and landed on the guide template. Cement Is pumped down the drill pipe and displaced with water, spotting the cement on the outside of the 30" back to the surface. The drill pipe is then retrieved, as are the two temporary guide cables extending from the guide template. A pin connector (Fig. 2) is sometimes used to latch onto the 30" conductor. This connector has a 20-3/4" bag type preventer on top to which Is attached a ball joint and 24" riser system to the surface. The 20-3/4" preventer is used when drilling out through the 30" conductor. It Is removed before running the 20" casing string. A 26" diameter bit is made up on the drill pipe and guided down into the 30" by means of the Universal guide frame on top of the bit. In general practice, approximately 500-ft. of 26" hole is then drilled. 252 Next, preparations are made for running the 20" casing. The 20" is run and guided Into the 30", again using the Universal guide frame as a stabbing means. When the 20" casing has entered the 30", the guide frame is retrieved by flexible lines and unhinged from around the casing. The 20" casing head is made up on the casing, a connector attached to the top of the head, and then the complete string picked up on drill pipe and lowered to the bottom. This 20" casing head lands on a shoulder in the top of the 30" with an annulus opening at the top for cement returns (Fig. 3). Cement Is pumped down the drill pipe with returns coming back to the surface through the annulus by-pass provided. The connector is unlatched hydraulically and retrieved. The 20-3/4" 2000 psi working pressure blowout preventer stack is picked up and run on drill pipe and hydraulically locked onto the 20-3/4" 2000 psi working pressure casing head housing. To test this connection, a mandrel type tester is landed at the taper in the casing head housing, the rams or a bag type preventer is closed around the drill pipe, and a pressure test is made on the connection. Next, a riser having a minimum bore of 21" is run and connected to the top of the blowout preventer stack by means of the connector shown in Figure 4. A ball joint is located just above the connector which locks at the top of the blowout preventer stack. This ball joint provides flexibility at the bottom of the riser to allow for lateral changes in position of the drilling vessel, thus eliminating severe stress in the blowout preventer stack. This joint, shown in Figure 6, normally al.lows for 10 degrees deflection, 20 degrees included angle. At the top of the riser, a slip joint Is provided to compensate for rise and fall of the vessel. A wear bushing (Fig. 7) is run and landed In the 20-3/4" casing head to prevent damage to the inside diameter of the casing head during drilling operation. A 17-1/2" hole is drilled to the required depth for running the next string, which will be 13-3/8" casing. The wear bushing is retrieved on drill pipe and then preparations are made for running the 13-3/8" diameter casing string. The weight and length of this string is in proportion to the total depth of the well to be drilled. The 13-3/8" casing Is run and a 13-5/8" casing head housing is made up on the last joint. A running tool Is made up Into the top of the casing head and lowered on 13-3/8" casing to a landing shoulder In the 20-3/4" casing head. Another means which is commonly used to lower the casing head Is a tool known as the Universal running tool. This tool is made up on drill pipe. Hydrauli- cally operated dogs on the Universal running tool lock into the casing head, and the head is then lowered on drill pipe. The capability to use drill pipe for lowering the casing head is highly desirable where water depths are such that It would not be practical to carry on board surplus casing for lowering the head to the bottom. In all instances It is common practice to run the 13-3/8" casing and head through the 20-3/4" blowout preventer stack. Two means have been used for cement returns: I) When the 13-5/8" casing head seals into the 20-3/4" head, a hydraulically operated dump valve below the landing shoulder Is opened to take returns. 2) In some Instances there Is no outlet In the 20-3/4" casing head; therefore, the 13-5/8" casing head housing has vertical slots on the outside diameter through which returns can be taken back to the surface. After the cement has been spotted, the running string is released and the area above the top of the 13-5/8" casing head is circulated clean. 253 The hydraulic connector Is then released from the 20-3/4" casing head, and the riser and 20-3/4" blowout preventer stack is retrieved. The next operation is to Install the 13-5/8" bore blowout preventer stack (Fig. 5) and a 16" riser system. The 13-5/8" blowout preventer stack will usually consist of a guide frame which fits over the wellhead guide frame, an automatic connector on bottom, three to four ram type blowout preventers, a bag type preventer, and a short adapter on top for attaching the marine riser. The stack also has outlets for what are called the "choke and kill" lines. A fall-safe valve is clamped or flanged to these outlets. The fail-safe valve is hydraulically opened, but will close automatically In case hydraulic pressure is released. The riser consists of a connector or latching means on bottom, a ball joint and riser pipe back to the surface where a slip joint is tied back to the floating platform. On the previous 21" riser and the 16" riser now run, guide arms with funnels can be provided for holding the choke and kill lines. These guide funnels provide a means by which the riser or the choke and kill lines can be pulled independently or guided back down. The hydraulic system for operating all of the components in the preventer stack is manifolded to a common point in the stack, and a hose bundle is run independently, locking onto this manifolding. The preventer stack is lowered independently on drill pipe, and a pressure test Is made on the connection before the pipe is pulled. It is common practice to run the choke and kill lines down with the preventer stack. The marine riser is then run Independently and locked to the top of the stack. A wear bushing is run on drill pipe and landed on a shoulder In the 13-5/8" casing head housing. A 12-1/4" inside diameter hole is drilled in preparation for running the 9-5/8" casing string. After this hole has been drilled, the wear bushing is retrieved on drill pipe and preparations are made for running the 9-5/8" casing. The 9-5/8" casing is run, and a casing hanger (Fig. 8) is made up on the string and then lowered either by casing or drill pipe. The casing hanger is landed on the shoulder in the 13-5/8" casing head housing. The 9-5/8" string is cemented, with returns taken through by-pass slots In the casing hanger. The running string is detached, and the hole is circulated clean above the casing hanger. The packoff assembly is run on drill pipe and made up on the casing hanger body (Fig. 9). A seal on the packoff assembly is compressed, packing off the annulus by torquelng up on the drill pipe. The combination running and testing tool (Fig. 10) has a cup that seals off inside the casing hanger body. The drill pipe rams in the blowout preventer stack are closed around the drill pipe, pressure Is applied through the choke and kill lines, and the annulus seal is tested to the required pressure. The lines are opened and the running and testing tool Is retrieved. The top preparation in this seal assembly has a landing shoulder for the next casing string. A wear bushing is again run on drill pipe and landed in the top of the 9-5/8" casing hanger assembly. The hole is drilled for the 7" casing which will be the production casing string. The wear bushing is retrieved on drill pipe and preparations are made for running the 7" casing string. The casing is run and once again a casing hanger body with by-pass slots Is made up on the string and lowered to the bottom by either casing or drill pipe, depending on water depth. (The drill pipe method again avoids carrying large amounts of surplus casing on board in deep water areas.) Returns are taken in the annulus and the same procedure is followed as in the 9-5/8" for circulating, running the packoff assembly, and testing. If the 9-5/8" casing becomes stuck before the casing hanger Is landed, the casing is then cemented in place and an emergency slip and seal assembly 254 (Fig. II) is used to support and seal the casing in the wellhead. The stack-up will remain the same. The procedure for running the emergency slip and seal assembly is as follows: I) If casing sticks before mandrel hanger Is landed, cement casing. 2) Cut off casing above where hanger should be landed, and remove casing above cut. 3) Run a spear on drill pipe and grip the inside of the casing. 4) Using the same size casing as was cut off and a 10-ft. overshot at the bottom, run the emergency slip assembly down over the drill pipe and land it on the landing taper in the casing head. 5) Pull the desired tension on the casing with drill pipe and spear. Then release spear and retrieve. 6) By right-hand rotation, release running tool from slip assembly and retrieve tool. 7) Cut off casing a fixed distance above top of slip assembly and remove loose piece. 8) Run seal assembly, rotate to the right to energize seals, pressure test seals and retrieve running and testing tool. The top of the 7" casing hanger seal assembly is prepared with a landing shoulder for the tubing hanger. When two or more tubing strings are to be run, it is necessary to orient the tubing hanger in reference to the wellhead guide frame so that the Christmas tree will be aligned with the seal pockets and the guide posts. This orientation is done by the following: I) An orienting bushing is run on drill pipe. 2) The bushing is landed on top of the 7" hanger and seal assembly and rotated slowly to the right until the orienting dog snaps out Into the orienting slot in the connector which is attached on the bottom of the blowout preventer stack. The drill pipe is then retrieved leaving the bushing in place. The inside preparation of this bushing is slotted so that when the tubing hanger is run, a key on the outside diameter of the hanger guides down the slot, thus automatically orienting the hanger in proper position with reference to the wellhead guide posts (Fig. 12). The tubing hanger has locking dogs for locking down in top of the 7" casing hanger assembly. The riser and blowout preventer stack (Fig. 13) are then retrieved. The design of this subsea system allows the following option to be exercised at this point: I) capping the well at this stage (Fig. 14) and waiting for future development and planning. If the decision is made to put the well into production at a later date, the cap can be removed, the casing extended back to the surface, and completion carried out on the platform. 2) continuing with preparations for subsea completion, which call for installing the production tree on the ocean floor. THE PRODUCTION TREE The Production Tree consists of a connector, two block valves, manifold spool, tree cap, and flowline connector (Fig. 15). The tree valve assembly includes a "wye" outlet spool with wing valves on which flowline loops are attached from the tree valve to the flowline connector. 255 The Production Tree is attached to the wellhead with a hydraulic collet connector that functions in principle like a standard wellhead connector. Guide arms on the connector give the tree its initial alignment as it is lowered into position and final alignment is obtained as the tree comes down over the neck of the tubing hanger. The close fit between the connector inside diameter and the tubing hanger neck outside diameter straightens the tree before it lands. The tree orients when the tubing hanger key engages the orienting slot in the connector inside diameter. The block tree valve (Fig. 16) contains a master valve unit, a wye outlets unit, and optionally, a swabbing valve unit. The tree valve may have either two or three vertical runs for a single completion well and at least three vertical runs for a dual completion. The wye outlets unit incorporates either two or three flowlines, each having a wing valve. The flowlines with a five foot radius arc intersecting the vertical runs permit passage of tools (pumped through the flowline) into the tubing. Provisions are made in the wye outlets unit to land a deflector tool. This deflector diverts the "pump down" or tubing tools back Into the flowlines when the tools are being retrieved. The deflector is run into the tree valve through the vertical tubing string from the drilling platform. The deflector Is oriented by and landed in a special seal sub between the wye unit and swabbing valve unit. The master valve unit, swabbing valve unit, and wing valves are equipped with fail-safe operators. The hydraulic lines to the valve operators may be ported internally within the tree valve units. A test port sleeve valve is located at the lower flange In one of the vertical runs; usually the casing annulus run (if an annulus run is used). This valve, when open, will vent from the vertical run Into the area sealed off by the connector when the tree is landed on the wellhead. It is used to test the seal made by the gasket and the seals on the lower end of the stab type seal subs. The tree is always landed with the test port sleeve valve open so fluid trapped in the bore of the connector when going over the wellhead may be exhausted. Immediately after the tree has been landed on the wellhead and the connector closed, a testing tool is run down the tubing and a high pressure test made to make sure the stabbing operation was successful. After the test has been completed, the sleeve valve is closed. The manifold spool is a spool mounted on top of the block tree valve. The lower face of the manifold spool connects the tubing runs and hydraulic operating system from the valve body to the manifold spool through a series of seal subs and is bolted or clamped to the valve body. The top face of the manifold spool contains stab type seal sub pockets for making the connection from the tree running connector to the tree. The upper end has a clamp hub and preparations for the installation of the tree cap. An orienting type guide post is mounted on the side to facilitate orienting and latching the running connector for reentry to the well. Technically speaking, the manifold spool could be eliminated, and the prepara- tion for attaching the connector incorporated in the top face of the block tree valve. The spool is used to allow replacing of the stab sub pockets without changing the block tree valve. It also allows the selection of a variety of hydraulic operating systems with the same basic block tree valve. If individual solid block master and swab valves are to be used, a wye outlet spool is bolted or clamped between the two block tree valves. The wye type outlets are made with a radius for passage of "pump down" tools from the flowilne to the tubing bore. When a wye spool is used, the deflector tools are installed in the spool just above the wye outlet. 256 The flowline loops are pipe sections running from the wing valve outlets on the production tree to the flowline connector. As mentioned earlier, they are made with a large radius in order to pass the "pump down" tools. The flowline connector is used to make the connection between the flowlines and the underwater production tree (Fig. 17). The tree hub section of the flowline connector is attached to the outer end of the flowline loops and is lowered into place with the production tree. After the tree has been tested and the flowlines layed with the flowline hub in place, the seal assembly Is lowered Into position and the flowline hubs are clamped together, completing the underwater production tree assembly. The tree cap is used to cover the top of the manifold spool, protecting the hub and seal sub ports after the tree running connector has been removed. The cap connects onto the manifold spool. The cap is run and retrieved with a hydraulic running tool, using wireline retrievable darts. THE FLOWLINE CONNECTOR The flowline connector provides the necessary make and break joint between the Christmas tree flowline loops and the production flowlines. The Christmas tree and production flowlines can be run and retrieved independently with the final joint being made when both the tree and the flowlines are in position. The remote hydraulic control lines, which operate the Christmas tree valves, run alongside the production flowlines and Christmas tree loops. The hydraulic control lines are connected at the same time that the Christmas tree loops and production flowllnes are connected. Because a hydraulically operated running and retrieving tool is used to make and break the connector, the lines can be Joined or released before or after the tree is capped. The construction of the Christmas tree loops provides the flexibility required when the tree hub is pulled toward the flowline hub to make the connection. A spring has been incorporated into the cartridge that supports the tree hub to insure that the two hubs are sufficiently clear of each other for landing and retrieving the clamp and seal assembly (Fig. 18). All of the seal pockets in the hub are tapered, and for protection are recessed inside the hub faces. Each hub has a groove on its outside diameter which receives the yokes of the running tool. Runners are attached to the flowline hub which lands on guide posts. This fixes the orientation of the sub pockets relative to the tree. The tree hub lands on two plates welded to the guide frame and is automatically aligned when the weight of the running and retrieving tool is set down on the yoke groove. Final alignment is obtained by a rocking action as the hubs meet the flat spacer portion of the guide and seal assembly. The tapered seal subs do not slide into engagement and eliminate the need for a precise alignment of the hubs; they only engage when the hubs are in place. The clamp assembly is like a standard clamp with the bottom half connected to a "U shaped" support and nut; the top half is connected to a stem threaded into 257 the nut. Turning the stem to the right tightens the clamp. Turning the nut to the right unlocks the clamp. The top half of the clamp has ears, which run In slots cut in the "U shaped" support. Two support arms welded to the seal assembly also run in these slots, thus both halves of the clamp are centralized and supported during the running and retrieving operations. The test port allows a pressure test between the outside diameter of the gaskets and control line seal subs. Drill pipe adapters fitted with spring loaded keys are used to tighten or unlock the clamp. The clamp Is tightened by using the drill pipe locking adapter, which engages one of the slots In the stem with Its spring loaded key. Using the drill pipe to turn the stem to the right tightens the clamp. A spring loaded nut stop key, mounted on the running tool frame engages a slot in the nut to keep the nut from turning. Hydraulic operating cylinders are connected to two yokes. When the running tool Is landed, the yokes fit over the grooves on the hubs so that the hubs can be hydraulically pulled together or pushed apart. When the yokes are opened up, pickup bars engage slots In the support arms welded to the guide and seal assembly. The procedure for running the flowline connector is as follows: I) Open the clamp. 2) Make up a joint of drill pipe in the running tool. 3) Connect three (3) hydraulic hoses to the running tool. 4) Pick up the running tool and pressure the closing hose (#1) to close the tool. 5) Set the running tool over the clamp and seal assembly, and pressure the opening hose (#2) to open the tool. When the tool Is open, It holds the clamp and seal assembly. 6) Put the running tool guide funnels around the two flowline guide cables extending from the guide structure. 7) When the running tool lands on the flowline and tree hubs, pressure the closing hose (#1) to draw the flowllne and tree hubs together. 8) Hold the closing pressure, and turn the drill pipe running string to the right to tighten the clamp. Bleed off closing pressure. 9) Test by pressuring through the test port hose (#3). 10) Release test pressure and retrieve the running tool assembly by pulling straight up. The procedure for removing the flowline connector is as follows: I) Remove the clamp locking adapter and nut stop from running tool, and Install the clamp unlocking adapter and stem stop. 2) Make up a joint of drill pipe In the running tool. 258 3) Connect two (2) hydraulic lines to the running tool opening and closing ports. 4) Pick up the running tool and pressure the closing hose. 5) Put the running tool guide funnels around the two flowline guide cables extending from the guide structure. 6) Remove the spider and lower the tool on the drill pipe. 7) When the running tool lands on the flowline and tree hubs, pressure the closing hose. 8) Turn the drill pipe running string to the right to unlock the clamp. 9) Release closing hose pressure, and pressure the opening hose to part the flowline and tree hubs. When the running tool Is open, It holds the clamp and seal assembly. 10) Release pressure and remove running tool and clamp and seal assembly'by pulling straight up. With drilling equipment now proven, the engineering search Is centered on undersea production equipment. As rigs go Into ever deeper water, greater demands will be put upon such subsea mechanisms as Christmas tree valves and flowlime connectors. Successful subsea mechanisms for oil well completions have been developed and are now being used -- as was shown In this discussion. It Is a surety. however, that continued engineering effort will result In still finer and more versatile equipment for the industry. 259 Ph = Ph C -P C C- rpm - Uh -I C C) -4 C 1111111 SNN I I I II I PIN CONNECTOR FIGURE 2 262 CASING HEAD HOUSING FIGURE 3 263 COLLET CONNECTOR FIGURE 4~ 264 _!!!!!!!!i!~ I ii 13-5/8 5000 PSI W.P. BLOWOUT PREVENTER STACK FIGURE 5 265 A BALL JOINT FIGURE 6 266 WEAR BUSHING FIGURE 7 26'7 i ~ i~~ CASING HANGER BODY FIGURE 8 268 SEAL ASSEMBLY ON HANGER BODY FIGURE 9 269 E:2;:::: SEAL ASSEMBLY RUNNING AND TESTING TOOL FIGURE 10 270 EMERGENCY SLIP AND SEAL ASSEMBLY FOR CASING FIGURE 11 271 TUBING HANGER FIGURE 12 272 o"II DRILLING STACK-UP FIGURE 13 273 MW . II A11/////', ' \\\\\ I I 'I HYDRAULIC CAPPING PLUG FIGURE 14 274 wu Wi z LL. > ILL. I~~~~~~~~~~~~~~~~-A 0 0 ~ ~ ~ ~ ~ Lu~~~~~~~~~~~~~~~~a LL. ~ ~ ~ PODCN WEL FIGURE 15 275 BLOCK TREE VALVE FIGURE 16 276 Removing Adapter Running Adapter I0~ 2 1 K Be ~~~~Nut Stop Dog Stem Stop Dog Clamp Running Neck Seal Assembly Tree Hub Flowline Hub FLOWLINE CONNECTOR- READY TO ACTUATE FIGURE 17 277 Flowline Guide Post Main Guide Post "BX" Type Flow Line Seal Sub Gasket do " Spring Cartridge ~o A=Control Line Seal Sub - - - _---_ --_-- _ I _I - / i ~ Tree Hub B Flowline Hub FLOWLINE CONNECTOR--WITH RUNNING FRAME REMOVED TELEMANIPULATOR SYSTEMS FOR DEEP-SEA OPERATIONS by Dr. John W. Clark Consultant San Diego, California Abstract "Telemanipulator Systems" (TMS) is suggested as a generic term for sys- tems to accomplish manual tasks at or near the sea floor. All such systems provide man with mechanical aids and protective structures appropriate to the environment and the task. Divers using power tools are telemanipulator systems; so are manned sub- mersibles equipped with external manipulators. Fully-remote (telechiric) systems may be considered to be a class of TMS. The three classes of TMS are complementary and arise from a common technology. Examples of telechiric systems now in use are presented, and guiding prin- ciples to aid in the selection of TMS for specific situations are outlined. The application of TMS to realistic sea-floor oil-field situations is illus- trated. Introduction Operations on the sea-floor are gradually superseding operations from the surface of the sea for many scientific, military, and economic activities. The oceanographic scientist can often study the flora and fauna, the geology, the chemistry, or the physics of the ocean more effectively from a base ko- cated on the sea-floor than from the classical oceanographic vessel. Some aspects of the Navy's task of protecting our country from enemy submarines can logically be done by means of bottom-mounted equipment. As the oil industry moves toward deeper water, a trend toward installing part or all of their production facilities on bottom becomes apparent. Freedom from troubles associated with weather motivates this move; as an unexpected bonus, one usually finds it less expensive to install a production facility on the bottom in very deep water than to build a stationary platform extending above the surface. The "deep-sea operations" of the title are those associated with installing, operating, and maintaining sea-floor facilities and installations. The opera- tions involved are in large part independent of the nature and purpose of the facility; things must be lifted, pushed, turned, and joined. All of the opera- 279 tions of construction and maintenance labor must be preformed in the hos- tile environment of the sea. The term "telemanipulator systems" or TMS is proposed as a generic term for systems to accomplish deep-sea operations as just defined. All of these systems are manned. They differ in the location of the man and in the com- plexity of the power operated mechanical aids and sensory assists which he is provided. The simplest possible telemanipulator system is a diver with hand and/or power operated tools. The most complex is a fully remote, mobile system with manipulators and TV's. Small submarines equipped with external ma- nipulators are telemanipulator systems, as are remote-controlled earth- moving machines for site preparation. A special kind of TMS is the "robot" or fully-remote manipulator. The dis- tinguishing feature of these systems is the complete physical separation be- tween the operator and the work; his only connection is by an electrical com- munication link. These systems may be referred to as "telechiric", from the Greek words meaning "distant hand". Telechiric systems must not be confused with automatic systems (these also are sometimes called "robots"). Telechiric systems are manned; automatic systems are not. Semi-automatic systems are fairly common, in which the operations are pre-determined but an operator can control the timing of each. Armed with these definitions, let us look at a few examples of TMS. Tele- chiric systems will be emphasized, since they are neither common nor fa- miliar. After discussing the examples, we will look at some of the opera- tions which TMS will be required to perform, and at the way in which the complex TMS which will be required to fully develop the deep ocean's re- sources may evolve. Finally, the pros and cons of each of the three types of TMS will be noted as an aid to the system engineer. Examples of TMS There are three basic categories of TMS: power tools and aids for divers external manipulating and/or sensing systems for DRV's telechiric systems The simplest TMS are power-operated aids for divers, such as wrenches or drills to aid in manual tasks and such as wet-subs to give the diver im- proved mobility. Some of the' diver's power tools can also be used by manipulator-equipped submersibles. Figure 1 is a familiar example of a DRV (Deep Research Vehicle); you all recognize Alvin, typical of the several research and work submarines now operational. The hull and propulsion system provide a base on which to mount the "arm"; the maneuverability of the hull is an integral part of the manipulating capability of the vessel. External TV may be used to augment vision through the portholes; sonar is helpful in dark or dirty water. These things taken together, the hull and propulsion, the "arm", and the TV and sonar constitute a TMS in which the man is encap- 280 sulated in a protective shell. Telechiric systems come in many shapes and sizes. The earliest under- water example of a telechiric system in the RUM, built at Scripps in 1959. Figure 2 shows this vehicle on the beach. RUM (Remote Underwater Manip- ulator) is a bottom-crawling vehicle equipped with a general-purpose "arm" and with four fixed TV cameras. The operator is at a control console in a trailer on the beach; the cable is five miles long. RUM is obviously limited to hard sea-floor regions and to simple tasks such as placing instruments on the sea-floor. Experience with RUM verified the soundness of the con- cept, and the need for much more engineering development of components. Figure 3 is a photograph taken in 1961 of a telechiric system to complete oil wells on the sea-floor without requiring intervention by divers. The well-head and the manipulator were designed as a system, to minimize the total cost. Since there will be many well-heads and few manipulators, the well-head was made as simple as possible and the manipulator as complex as necessary. The operation of the system is shown in Figure 4 (a drawing, since photo- graphy of large-scale scenes in deep water is very difficult). The manip- ulator is suspended from a surface vessel, lowered to proper depth and guided to the well-head by the operator. Two marine screws maneuver the unit; sonar, television, a gyrocompass, and a hydrophone provide him with sensory data. After the remote unit is landed on the track on the well-head, hydraulic cylinders move a torque wrench vertically, azimuthally, and radially to engage with any one of a number of screws which hold the well- head sections together. This system will work in water up to 1000 ft. dtep. The man who operates the system is in a cabin in the interior of the support vessel on the surface. The safety and comfort of the operator, the ease of changing shifts, and the accessibility of the control desk to supervisory and personnel are advantages in this (or any other) telechiric system. This telechiric well-completion system has been in fairly continuous use on the West Coast since 1961. It has been re-built a number of times, but the original concept is retained. The term "robot" sometimes applied to this system is a misnomer; this is a manned system and has no pre-determined programs or computers associated with it. It is better regarded as a very complex tool whose user may be several hundred feet away from the work site. A telechiric system for recovery of experimental torpedoes is shown in Figure 5. Called "CURV" (Cable-controlled Underwater Research Vehicle), the remote unit is mobile in three dimensions and equipped with a grasping device matched to the torpedo to be recovered. TV and sonar are used to locate the target. After the grasping device is attached to the target, it is ejected from CURV and the target hoisted aboard by a separate line. CURV can work to 2000 ft. and recover payloads to one ton. Developed and used by NOTS-Pasadena, CURV has been successfully recovering torpedoes for some years. A telechiric system without a cable has been developed at the Applied Phys- ics Laboratory at the University of Washington, Seattle, Washington. Fig- ure 6 shows this carrier for scientific instruments, which is commanded 281 to dive, turn, stop, start, and surface by coded sonar pulses. In future, much more versatile telechiric systems will be needed than the special-purpose machines just described. The successful operation of the present generation of telechiric machines in spite of limited budgets, un- skilled operators, and other practical problems demonstrates that the con- cept of a remote tool is a reasonable one that can be reduced to practice by straight-forward engineering; and that the tools can be operated by non-sci- entific skilled personnel. The future telechiric system may look something like Figure 7, which is an artist's concept of a general-purpose system with its operator controlling it from a small submarine. Such a system would do the same tasks that divers do in shallow water, with no inherent limitation as to depth or time on bottom. It would be supplemented by a fleet of other telechiric vehicles, some specialized to a specific task like the well-completion manipulator, and others designed for heavy work like an underwater remote-controlled bulldozer. The question "Why not put a man inside?" is sometimes raised when sys- tems like the one in Figure 7 are discussed. The question refers to the remote-controlled vehicle in the foreground, not to the inhabited vehicle in the background. If a man wereput inside the remote vehicle, it could no longer be made small, simple, and maneuverable. An openwork structure like CURV (Figure 5) would not be possible. A life-support system would have to be added; in fact, it would be a DRV, and not a system distinctly different in capability. Why TMS? The alternatives sometimes offered to telemanipulator systems are of two opposite kinds: the unaided diver, and the semi-automatic system controlled from the surface. As oceanic enterprises go to deeper water, the utility of divers can only de- crease. The current spectacular progress with mixed-gas diving has ex- tended the practical limit at which a diver can do economically useful work to 300 ft. or more, and this figure is certain to increase. A large fraction of the continental shelf is already accessible to divers. Power-operated tools and devices can increase the productivity of a diver at any depth, by reducing the demands on his large muscles and using him primarily as a set-up man and observer. Diver power tools are a simple form of telema- nipulator system; as divers go deeper, their ability to do muscular work decreases, and the value to them of telemanipulator systems increases. Thus we see that the diver is not an alternative to a TMS at all; to the con- trary, he is a user of them. To examine the second alternative to TMS, the semi-automatic surface-con- trolled system, let us consider a simple, but completely typical example. Valves with handwheels are common in oil-fields, whether undersea or not; and the handwheel must be turned from time to time. Minor maintenance of the valve body must be accomplished on a pre-planned schedule. 282 If the water is not too deep, a diver can accomplish these tasks, aided per- haps by appropriate tools. The obvious alternative is to apply a hydraulic or electric motor to the valve, controlled from a shore point or a surface vessel, so that the valve can be opened or closed at will. Valves can be actuated in this fashion at any depth -- so one may well ask, "Why TMS? One reason is cost. Valve motors are expensive, and a typical oil produc- tion facility may have several hundred of them within a small area. Only one telemanipulator system is needed (as long as only one valve needs to be turned at a time) in the area; and quite a complex TMS can be built for the cost of a few valve motors and their associated control lines. Each case is different, of course, but very often the TMS offers a decisive ad- vantage. The second reason is maintenance. Any TMS is movable and can be brought to the surface for maintenance and repair. The valve motor, in contrast, is integrated into the valve; maintenance of the valve motor and the valve body must be performed on site, and a TMS is necessary to accomplish it. The third reason arises from the inevitable malfunctions and accidents. Most valve actuators provide a manual over-ride to use in case of malfunc- tions; a TMS enables one to actuate the manual over-ride at the bottom of the ocean. These three reasons apply to any more complex surface-controlled com- ponents; another example is the "diverless" well-heads now being offered by a number of manufacturers. A cost comparison may favor this type of well-head, depending on the number of wells in the field and the depth of water. But even if a "diverless" well-head is selected, TMS must be avail- able for routine maintenance and for coping with the inevitable malfunctions. The prob lems of re-entering the well becomes simple if TMS are available. Selection of TMS Preliminary guidelines to aid in selection of a TMS for a particular situa- tion can be stated. Some may disagree with these; and experience will cer- tainly alter and refine them. Depth of water and task complexity are the principal criteria. The three types of TMS, as one would expect, have fields of application which overlap but are distinguishable. Divers with power tools When the water is not too deep, these should always be selected. As water depth increases, the diver's muscular capability decreases and the com- plexity of tools that he can use with good economy increases. Tools can be small and simple or large and complex, depending on the task. For tasks requiring more than a few hours to complete, the divers should be provided with a supporting base to which they can return for rest periods while re- mainlng under pressure. Several variations on the diving bell principal are in use to meet this need. 283 DRV's with external aids A DRV can operate at much greater depth than a diver; its principal value is as a platform from which to make visual observations. A DRV is of necessity fairly large; it is difficult to make its life-support capsule less than 6 ft. OD. This large, un-maneuverable structure makes a rather un- satisfactory platform on which to mount a manipulator. The control sys - tems for the vehicle and for the manipulator must be integrated if complex manipulatory tasks are to be performed. It may be unduly hazardous, both to the DRV and to the structure to bring the DRV very close to a fragile structure like an oil-well. Performance and time-on-bottom of DRV's are limited by their on-board power. They are most economical for missions lasting a few hours. Sur- prisingly, divers in deep water are most economical for missions lasting several days, since the cost of travel to the site and the decompression penalty are almost independent of the time-on-bottom. Telechiric systems Sometimes called "remote-control systems", "robots", or "universal ma- nipulators", these systems are best thought of as very complex tools opera- ted by a man at a considerable distance from the work site. They are some- times called "unmanned" in contrast with DRV's which are "manned". This is a misconception. Both systems are manned; the difference lies in the location of the man. Telechiric systems are most valuable in very deep water, where divers or even DRV's cannot go. The occupation and development of the very deep ocean will be done by telechiric systems if it is done at all. Even in shallow water, telechiric systems are valuable for hazardous work or work too heavy for an unaided diver. Telechiric systems are expensive today, since they are made one-at-a-time; but they are not inherently costly. As acceptance of remoted systems increases, it will be possible to reduce their cost and thus reduce the depth at which a telechiric system is more economical than a diver with power tools and support equipment. The TV, sonar, and other sensors of a telechiric system are constantly available to supervisory and technical observers. Sometimes this feature is valuable, as contrasted with the need to depend on second-hand, delayed reports from DRV crews or from divers. Conclusions This paper will have served its purpose if the simple point that divers, DRV's and "robots" are complementary rather than competitive can be ac- cepted. A coherent engineering discipline is identified as one studies TMS. The performance of underwater tasks requires actuators and sensors. These may be used by divers, attached to the exterior of DRV's, or integrated into telechiric systems. This new, nameless discipline will probably be- come a major sub-classification of the equally new subject of ocean engi- neering. 284 The designer of deeper-water systems must needs be well informed of the advantages and the disadvantages of each type of TMS, so his overall sys- tem will be economical. The conclusion, then, is, "There is no one best way; but it can be done! ". --: 285 mIs, l- 50 l l '- _d . Alvin, a typical DRV with external manipulator Figure 1 286 NON RUM, a bottom-crawling telechiric system Figure 2 287 ge~ ~ ~~~~Fgr 3 ~~~~?M ~ ~ ~ ~ 8 OQ ba~~~~ C.. ....... CONTROL CONSOLE CIA~~~~~~~~~~~~~, ~~~~~~~~~SPOR *1~~~~~~~~~SI oa 0 TORPIEDON BOTTO a sonar-commanded telechiric instrument carrier Figure 6 291 \ ,)~~~~~~ equlibiu. Artist's concept of a future telemanipulator system at work in a sea-floor oil field Figure 7 292