HR: 14:40h
AN: U13A-04    [Abstracts]
TI: Source process and tsunami generation of the December 2004 and March 2005 Sumatra-Andaman earthquake
AU: * Thio, H
EM: hong_kie_thio@urscorp.com
AF: URS corp, 566 El Dorado Street, Pasadena, Ca 91101 United States
AU: Ichinose, G
EM: gene_ichinose@urscorp.com
AF: URS corp, 566 El Dorado Street, Pasadena, Ca 91101 United States
AU: Polet, J
EM: polet@crustal.ucsb.edu
AF: Institute for Crustal Studies, University of California, Santa Barbara, 1140 Girvetz Hall, Santa Barbara, Ca 93106 United States
AB: We are studying the source process of the 2004 Sumatra-Andaman earthquake using seismic, geodetic and tsunami data. Aftershocks of the earthquake suggest that the fault plane extended for more than 1000 km from Banda Aceh to the north Andaman Islands. Inversion results of long-period (80-300 sec) seismic waves suggest that the moment amounts to 6.4 x 10E29 dyne.cm with most of the slip concentrated on the southern section of the subduction zone from Aceh to the Nicobar islands. Although this earthquake model predicts the general pattern and features of tsunami observations around the Indian Ocean, there appears to be some systematic underprediction of the amplitudes. We are refining our analysis of this earthquake by including more seismic data as well as tsunami and geodetic observations to determine whether this discrepancy is due to an underestimate of shallow slip, imbricate faulting, extensive submarine landslides or other mechanisms. For the March 2005 earthquake, we find that the current seismic models are in good agreement with observed tsunami heights, and reflect the large difference in runup heights between this and the December 2004 event. We will update our rupture model with other observations as well.
DE: 4564 Tsunamis and storm surges
DE: 7215 Earthquake source observations (1240)
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 9320 Asia
DE: 9340 Indian Ocean
SC: Union [U]
MN: Fall Meeting 2005