Published May 20, 2005
| public
Journal Article
Earth's Free Oscillations Excited by the 26 December 2004 Sumatra-Andaman Earthquake
Abstract
At periods greater than 1000 seconds, Earth's seismic free oscillations have anomalously large amplitude when referenced to the Harvard Centroid Moment Tensor fault mechanism, which is estimated from 300- to 500-second surface waves. By using more realistic rupture models on a steeper fault derived from seismic body and surface waves, we approximated free oscillation amplitudes with a seismic moment (6.5 × 10^(22) Newton·meters) that corresponds to a moment magnitude of 9.15. With a rupture duration of 600 seconds, the fault-rupture models represent seismic observations adequately but underpredict geodetic displacements that argue for slow fault motion beneath the Nicobar and Andaman islands.
Additional Information
© 2005 American Association for the Advancement of Science. Received 15 March 2005; accepted 29 April 2005. This work was supported in part by NSF. Seismic waveform data from the Global Seismographic Network (funded by NSF and U.S. Geological Survey) were obtained from the Incorporated Research Institutions for Seismology (IRIS) Data Management System. Seismic waveform data was also obtained from the Geoscope Program (IPGP France) and the Southern California Earthquake Center.Additional details
- Eprint ID
- 20880
- Resolver ID
- CaltechAUTHORS:20101118-093342990
- NSF
- USGS
- Created
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2010-11-18Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Caltech Tectonics Observatory, Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Tectonics Observatory
- Other Numbering System Identifier
- 63