HR: 11:20h
AN: U22A-04    [Abstracts]
TI: Rupture process of the 2004 great Sumatra-Andaman earthquake estimated from tsunami waveforms
AU: * Tanioka, Y
EM: tanioka@eos.hokudai.ac.jp
AF: Hokkaido University, N10W8 Kitaku, Sapporo, 060-0810 Japan
AU: Yudhicara, .
U22A-04 AF: Bandung Institute of Technology, Jalan Ganeca 10, Bandung, 40132 Indonesia
AU: Kathiroli, S
U22A-04 AF: National Institute of Ocean Technology, Velachery-Tambaram Main road, Pallikaranai, Chennai, 601302 India
AU: Nishimura, Y
U22A-04 AF: Hokkaido University, N10W8 Kitaku, Sapporo, 060-0810 Japan
AU: Iwasaki, S
U22A-04 AF: National Research Institute for Earth Science and Disaster Prevention, 3-1 Tennodai, Tsukuba, 305-0006 Japan
AU: Kusunose, T
U22A-04 AF: Hokkaido University, N10W8 Kitaku, Sapporo, 060-0810 Japan
AB: Rupture process of the 2004 Sumatra-Andaman earthquake is estimated using five tsunami waveforms observed at tide gauges (Sibolga Belawan, Colombo, Vishakhapatnam, and Prot Blair) and tsunami height data obtained from two satellite altimetry data, _gJason-1_h and _gTOPEX/Poseidon_h. The coseismic vertical deformation surveyed along the coast of Sumatra Island, Nicobar Islands, and Andaman Islands, are also used to constrain the fault model. The average rupture speed of the 2004 Sumatra-Andaman earthquake is estimated to be about 2 km/s from tsunami waveform analysis. The rupture extends about 1200 km toward north-northwest along the Andaman trough. The large slip of more than 20m is estimated on the plate interface off the northwest coast in the Aceh province in Sumatra. Another large slip of more than 20m is also estimated on the plate interface beneath the north of Simeulue Island in Indonesia. The other large slip of 10-15m is estimated on the plate interface near Little Andaman and Car Nicobar Inlands. The slip amount beneath North and Middle Andaman Islands are very small, about 1m. The total seismic moment is calculated to be 7.8 x 10²² Nm (Mw 9.2) which is similar to the other studies using seismic waves (Park et al., 2005, Ammon et al., 2005). Our estimated slip amount off Sumatra Island is larger than the slip amounts estimated by the other studies, such as Ammon et al (2005). This large slip should be responsible for large tsunami run-up heights of about 35m surveyed along the northwest coast of Ache province in Sumatra Island.
DE: 3060 Subduction zone processes (1031, 3613, 8170, 8413)
DE: 4564 Tsunamis and storm surges
DE: 7215 Earthquake source observations (1240)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Union [U]
MN: Fall Meeting 2005