[Federal Register Volume 72, Number 108 (Wednesday, June 6, 2007)]
[Notices]
[Pages 31351-31353]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-2809]


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NATIONAL SCIENCE FOUNDATION


Notice of the Availability of a Draft Environmental Assessment

AGENCY: National Science Foundation.

ACTION: Notice of availability of a draft Environmental Assessment for 
proposed activities in the Eastern Tropical Pacific Ocean.

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SUMMARY: The National Science Foundation (NSF) gives notice of the 
availability of a draft Environmental Assessment (EA) for proposed 
activities in the Eastern Tropical Pacific Ocean.
    The Division of Ocean Sciences in the Directorate for Geosciences 
(GEO/OCE) has prepared a draft Environmental Assessment for a pair of 
marine geophysical surveys by the Research Vessel Marcus G Langseth in 
the Eastern Tropical Pacific Ocean, in international waters (2000-5000 
meters depth) between 5[deg] S and 11[deg] N, along ~105[deg] W during 
September-December 2007. The draft Environmental Assessment is 
available for public review for a 30-day period.

DATES: Comments must be submitted on or before July 6, 2007.

ADDRESSES: Copies of the draft Environmental Assessment are available 
upon request from: Dr. William Lang, National Science Foundation, 
Division

[[Page 31352]]

of Ocean Sciences, 4201 Wilson Blvd., Suite 725, Arlington, VA 22230. 
Telephone: (703) 292-7857. The draft is also available on the agency's 
Web site at: http://www.nsf.gov/geo/oce/pubs/MGL--ETP--2007--EA.pdf.

SUPPLEMENTARY INFORMATION: Lamont-Doherty Earth Observatory (LDEO), 
with research funding from the NSF, plans to conduct two marine seismic 
surveys in the Eastern Tropical Pacific Ocean (ETP) during 2007. The 
research programs will take place in international waters of the ETP at 
least 890 km from any coast. The surveys will use a towed airgun array 
consisting of up to 27 operating airguns with a maximum discharge 
volume of 4950 in\3\. The studies will take place in offshore waters 
>2000 m deep.
    The first survey will start in September 2007 and will obtain 
seismic reflection images of the internal structure of the magmatic-
hydrothermal system at the fast-spreading mid-ocean ridge of the East 
Pacific Rise (EPR). The seismic data from the EPR survey will be used 
to advance our understanding of the linkages between the fundamental 
process of crustal creation at the mid-ocean ridge and the biological 
systems that thrive in the absence of sunlight at deep sea volcanoes. 
The survey will allow the characterization of the fundamental heat 
source driving the seafloor hydrothermalism in the EPR, by examining 
the subsurface magma system. It will also provide an understanding of 
the relationships between the temporal variations in subsurface magma 
systems and highly transient phenomena observed at the seafloor like 
faulting, volcanism, and hydrothermal venting. Hydrothermal systems are 
of great interest in that they may be linked to the origin of life in 
early Earth history.
    The second survey is expected to take place from early November 
through December 2007. It will examine two important types of seismic 
behavior of the Quebrada, Discovery, and Gofar fault systems (QDG) to 
understand better the behavior of earthquakes and faults in general. 
Oceanic transform faults, such as the QDG, are the most poorly studied 
of the various types of plate boundaries. The QDG survey will examine 
the seismogenic properties that make oceanic transforms unique, 
including abundant foreshocks before large earthquakes, slow ruptures, 
and large variations in fault seismic coupling. The two main questions 
to be addressed by the study are: (1) Do large and small earthquakes 
nucleate in the same way, or is there some kind of fault preparation 
process before large events, and (2) why do some faults remain locked 
for decades to centuries between large earthquakes while others creep 
aseismically and never have a large event? Refraction images of the 
material properties in both fault zones will provide important 
information about the physics of faulting and the earthquake process.
    The first survey (EPR) is a multichannel seimic (MCS) reflection 
survey in a 3D configuration. The survey will consist of two racetrack 
configurations with a total of 36 loops that will cover an area of ~28 
x 28 km. The Langseth will deploy a 36-airgun array as an energy 
source. However, two identical two-stirring sources will be firing 
alternately, so that no more than 18 airguns will be firing at any 
time. The maximum discharge volume will be 3300 in3. The 
Langseth will also tow the receiving system, which consists of four 6-
km hydrophone streamers; each streamer will be located 100 m from the 
adjacent streamer. The second study (QDG) will consist of a refraction 
survey done in a 2D configuration. It will consist of two north-south 
lines, each ~122 km in length, each to be surveyed twice. If there is 
time, two 25-km west-east lines will also be surveyed, and one of the 
north-south lines will be resurveyed. With the contingency surveys, the 
study will consist of a total of 654 km of survey lines, including 
turns. The Langseth will deploy a 36-airgun array as an energy source. 
However, no more than 27 airguns will be fired at any time. The maximum 
discharge volume will be 4950 in3. A single 8-km streamer 
will be deployed. The Langseth will also deploy 40 long-term OBSs, 
deployed over a 50-km wide spread. The long-term OBSs will be recovered 
1 year after deployment. Another 8-10 short-term OBSs will be deployed 
on each line, which will be retrieved after the seismic surveys are 
completed.
    LDEO has applied for the issuance of an Incidental Harrassment 
Authorization (IHA) from the National Marine Fisheries Service (NMFS) 
to authorize the incidental harassment of small numbers of marine 
mammals during the seismic survey. the information in this 
Environmental Assessment supports the IHA permit application process, 
provides information on marine species not covered by the IHA, and 
addresses the requirements of Executive Order 12114, ``Environmental 
Effects Abroad of Major Federal Actions''. Alternatives addressed in 
this EA consist of a corresponding seismic survey at a different time, 
along with issuance of an associated IHA; and the no action 
alternative, with no IHA and no seismic survey.
    Numerous species of cetaceans and sea turtles occur in the Eastern 
Tropical Pacific Ocean. Several of the cetacean species are listed as 
endangered under the U.S. Endangered Species Act (ESA), including the 
humpback, sei, fin, blue, and sperm whales. Sea turtles that are known 
to occur in the ETP include the endangered leatherback, green, olive 
ridley, and hawksbill turtle, and the threatened loggerhead turtle.
    The potential impacts of the seismic surveys would be primarily a 
result of the operation of airguns, although a multi-beam sonar and a 
sub-bottom profiler will also be operated. Impacts may include 
increased marine noise and resultant avoidance behavior by marine 
mammals, sea turtles, and fish; and other forms of disturbance. The 
operations of the project vessel during the study would also cause a 
minor increase in the amount of vessel traffic. An integral part of the 
planned survey is a monitoring and mitigation program designed to 
minimize the impacts of the proposed activities on marine mammals and 
sea turtles that may be present during the proposed research, and to 
document the nature and extent of any effects. Injurious impacts to 
marine mammals and sea turtles have not been proven to occur near 
airgun arrays; however the planned monitoring and mitigation measures 
would minimize the possibility of such effects should they otherwise 
occur.
    Protection measures designed to mitigate the potential 
environmental impacts will include the following: a minimum of one 
dedicated marine mammal observer maintaining a visual watch during all 
daytime airgun operations, and two observers for 30 minutes before 
start up. A passive acoustic monitoring (PAM) array will be monitored 
24 hours per day while at the survey area during airgun operations and 
when the Langseth is underway while the airguns are not operating. The 
use of ramp-up, as well as implementation of power-down or shut-down 
procedures when animals approach a designated exclusion zone (EZ) are 
also important mitigation measures. LDEO and its contractors are 
committed to apply those measures in order to minimize disturbance of 
marine mammals and sea turtles, and also to minimize the risk of 
injuries or of other environmental impacts.
    With the planned monitoring and mitigation measures, unavoidable 
impacts to each of the species of marine mammal that might be 
encountered are expected to be limited to short-term localized changes 
in behavior and

[[Page 31353]]

distribution near the seismic vessel. At most, such effects may be 
interpreted as falling within the Marine Mammal Protection Act (MMPA) 
definition of ``Level B Harassment'' for those species managed by NMFS. 
No long-term or significant effects are expected on individual marine 
mammals, or the populations to which they belong, or their habitats. 
The agency is currently consulting with the NMFS regarding species 
within their jurisdiction potentially affected by this proposed 
activity.
    Copies of the draft EA, titled ``Environmental Assessment of two 
Marine Geophysical Surveys by the Marcus G. Langseth in the Eastern 
Tropical Pacific, 2007,'' are available upon request from: Dr. William 
Lang, National Science Foundation, Division of Ocean Sciences, 4201 
Wilson Blvd., Suite 725, Arlington, VA 22230. Telephone: (703) 292-7857 
or at the agency's Web site at: http://www.nsf.gov/geo/oce/pubs/MGL ETP 
2007 EA.pdf. The NSF invites interested members of the public to 
provide written comments on this draft EA.

    Dated: May 31, 2007.
Dr. Alexander Shor,
Program Director, Oceanographic Instrumentation and Technical Services, 
Division of Ocean Sciences, National Science Foundation.
[FR Doc. 07-2809 Filed 6-5-07; 8:45 am]
BILLING CODE 7555-01-M