Research Contributions
The Maurice Ewing, owned by the National Science Foundation
and operated by the Lamont-Doherty Earth Observatory (L-DEO),
is the only research vessel devoted to obtaining images of the
deep earth for fundamental earth science research.
These images provide information about
earth’s active processes,
such as the recent earthquake in the Indian Ocean and subsequent
tsunami. Only by mapping in and under the ocean can improvements
be made in our ability to define the risks associated with major
earthquakes, tsunamis, volcanoes, landslides and climate change.
(http://www.ldeo.columbia.edu/res/fac/oma/mmp).
Many of earth’s systems, such as
earthquakes, occur deep within the crust, many miles beneath
the ocean floor. The only way to 'look' at craters, faults and
other underwater structures is with the use of sound waves.
Sound waves are reflected back from the target, allowing researchers
to determine precisely where the earthquake faults are located,
where undersea volcanoes are likely to erupt, and where hydrothermal
vent systems are operating, among other things.
Most recently, scientists aboard the Ewing made detailed maps
of the large earthquake producing faults in Venezuela and the
southeast Caribbean Sea, and off the coast of Washington State
in the northeast Pacific along the Blanco Fracture Zone.
The collection of these sound images
is a complex and sophisticated process requiring highly specialized
equipment. More than 30 American universities and numerous international
centers depend on information gained by the Ewing’s acoustic research capabilities to
advance their understanding of Earth’s complex systems.
The seismic research carried out by the Ewing
is different in significant ways from the sonar studies the Navy
conducts. The academic community continues to work diligently
to determine the impact of air guns on marine mammals. Currently,
there seems to be a small but undefined risk to marine mammals,
but only through continued thorough research will any such risks
be quantified and understood. L-DEO is
taking a leadership role to develop and study the data in a
series of advisory committees and symposia under the direction
of the National Academy of Sciences and the Marine Mammal Commission.
Chicxulub Crater research off the Yucatan peninsula;
January 2005
The Chicxulub Crater in Mexico is the
largest impact crater yet discovered on Earth and records one
of the most significant events in the Earth’s history.
The impact by an asteroid or comet may have caused mass extinction
some 65 million years ago, wiping out dinosaurs, among other
species.
Scientists from the University of Texas Institute of Geophysics,
the Instituto Geofisica of the Universidad Nacional Autonoma de
Mexico (UNAM) and the Universities of Cambridge and London in
the United Kingdom are undertaking the current research of the
Chicxulub Crater. This international team will examine the direction
of the approach of the asteroid or comet, and map the deformation
recorded in the upper crust.
The study also seeks to understand the physical
parameters of the Chicxulub impact structure and to create a three-dimensional
model of the collapse of the crater. The findings will help scientists
to better understand the mechanics of large impact craters and
quantify many of the environmental effects of the Chicxulub impact.
The landward extent of the crater also will be mapped by land
seismometers.
Status of Permits for the Chixculub Crater cruise
As operators of the Ewing, L-DEO has the appropriate
permits from the Office of Protected Resources of the U.S. National
Marine Fisheries Service (NMFS), which has conducted all appropriate
environmental assessments. L-DEO also has obtained the necessary
permits from the Direccion General de Impacto y Riesgo Ambiental
of the Secretaria de Medio Ambiaent y Recursos Naturales (SEMARNAT)
and the Secretaria de Relaciones Exteriores of Mexico.
Permits are obtained for each research trip
under the Marine Mammal Protection Act, administered by the NMFS.
Operational procedures have been adopted that
minimize any possibility of interaction between the Ewing and
marine mammals, and include avoidance of seismic operations during
mating or calving seasons, establishment of safety zones around
the vessel, monitoring and detecting submerged animals by aerial
and marine observation, and restrictions on nighttime operations.
L-DEO is recognized as a leader in the development
and implementation of marine mammal mitigation.
Additional mitigation
procedures in place for the Chixculub Crater Cruise
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Operations
have been scheduled for a time of year to minimize impact
to marine life and fishing activities.
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Six
skilled marine mammal observers, including two researchers
appointed by SEMARNAT and
one from a non-governmental organization, are participants
of the team that will insure that marine mammals do not approach
the vessel too closely while seismic operations are underway.
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The
marine mammal observers have the authority to stop the seismic
operations at any time if there is reason to believe there
exists a potential for harm to marine mammals.
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A
passive acoustic monitoring system will be used to listen
for vocalizations of marine mammals, alerting the observers
to the presence of submerged animals.
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Approximately
15 over flights will occur prior to, during and upon completion
of the seismic survey to provide aerial surveillance to
detect presence of marine mammals and fishing activities long
before they come close to the research vessel and to determine
that no marine animals have been injured or disturbed during
the seismic activities.
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No
active seismic operations will be carried out at night.
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The
amount of active seismic operations has been reduced 38%
from that originally planned in order to further reduce the
possibility of interference with the marine animal populations.
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A small boat will be in constant attendance to further improve
marine mammal observational capabilities and to advise fishing
vessels of the intended track of the seismic survey.
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