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Earth's Free Oscillations Excited by the 26 December 2004 Sumatra-Andaman Earthquake

Park, Jeffrey and Song, Teh-Ru Alex and Tromp, Jeroen and Okal, Emile A. and Stein, Seth and Roult, Genevieve and Clévédé, Eric and Laske, Gabi and Kanamori, Hiroo and Davis, Peter and Berger, Jon and Braitenberg, Carla and Van Camp, Michel and Lei, Xiang'e and Sun, Heping and Xu, Houze and Rosat, Severine (2005) Earth's Free Oscillations Excited by the 26 December 2004 Sumatra-Andaman Earthquake. Science, 308 (5725). pp. 1139-1144. ISSN 0036-8075. doi:10.1126/science.1112305.

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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.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Song, Teh-Ru Alex0000-0003-3697-5881
Tromp, Jeroen0000-0002-2742-8299
Kanamori, Hiroo0000-0001-8219-9428
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.
Group:Caltech Tectonics Observatory
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Caltech Tectonics Observatory63
Issue or Number:5725
Record Number:CaltechAUTHORS:20101118-093342990
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:20880
Deposited By: Tony Diaz
Deposited On:18 Nov 2010 18:40
Last Modified:09 Nov 2021 00:04

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