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David E. Steitz
Headquarters, Washington
(Phone: 202/358-0474)

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-0474)

December 2, 2003
NASA Contributes To Earthquake Research
Ten years ago next month, Southern California was rocked by the deadly magnitude 6.7 Northridge earthquake, one of the costliest natural disasters in U.S. history. The quake was preceded by concentrated pre-earthquake strain in the region, detected by sparse readings from newly developed Global Positioning System (GPS) deformation monitors.

NASA's unique contributions to this rapidly maturing field of study and implications of this research for mitigating future seismic hazards are the focus of a Earth Science Update, Thursday, 1 p.m. EST in NASA's Webb Auditorium, 300 E Street S.W., Washington.

In the 10 years since the devastating Northridge earthquake, a high tech GPS based ground deformation network was installed within Southern California. It provides a continuous measurement of ground deformation at 250 locations with a precision of a few millimeters.

Advances in satellite based radar Interferometric Synthetic Aperture Radar and lidar are combined with the GPS measurements to provide images of ground deformation for the entire Southern California earthquake region. Researchers obtained very surprising results, from the discovery of quiet earthquakes to imaging ground water withdrawal rates. These new high accuracy, space based radar, lidar, and GPS measurement technologies, coupled with powerful new computer modeling capabilities, have revitalized research in earthquake prediction with a new understanding of how the Earth's surface is changing.


Dr. Andrea Donnellan, geophysicist and deputy manager, Earth and Space Sciences Division, NASA Jet Propulsion Laboratory, Pasadena, Calif.

Dr. Bradford H. Hager, professor, Massachusetts Institute of Technology, Cambridge, Mass.

Dr. John B. Rundle, professor and founding director, Computational Science and Engineering Center, University of California, Davis, Calif.

Dr. Wayne Thatcher, senior research geophysicist, U.S. Geological Survey, Menlo Park, Calif.

Dr. James H. Whitcomb, section head for Special Projects, Earth Sciences Division, National Science Foundation, Arlington, Va.

The program will be carried live on NASA Television with two-way question-and-answer capability from participating agency centers. NASA TV is available on AMC-9, transponder 9C, C-band, located at 85 degrees west longitude. The frequency is 3880.0 MHz. Polarization is vertical, and audio is monaural at 6.80 MHz. Audio of the broadcast is available on voice circuit by calling: 321/867-1220/1240/1260.

For the live webcast, click the "Watch NASA TV Now!" link at:

For information about NASA's Earth Science Enterprise on the Internet, visit:


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