Lamont Doherty Earth Observatory Contributes Vital Research

January 5, 2005
News Subtitle: 
for a Strong International Environmental Agenda and a Sustainable Global Future

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. (

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

  • Operations have been scheduled for a time of year to minimize impact to marine life and fishing activities.

  • 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.

  • 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.

  • A passive acoustic monitoring system will be used to listen for vocalizations of marine mammals, alerting the observers to the presence of submerged animals.

  • 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.

  • No active seismic operations will be carried out at night.

  • 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.

  • 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.