HR: 0800h
AN: U11A-0818    [Abstracts]
TI: Slip Distribution of the 2004 Sumatra-Andaman Earthquake from Near-field GPS Observation
AU: * Irwan, M
EM: irwan@seis.nagoya-u.ac.jp
AF: Research Center for Seismology, Volcanology and Disaster Mitigation Nagoya University, Furo Cho Chikusa Ku, Nagoya, 464-8602 Japan
AU: Ohta, Y
EM: oota@eps.nagoya-u.ac.jp
AF: Research Center for Seismology, Volcanology and Disaster Mitigation Nagoya University, Furo Cho Chikusa Ku, Nagoya, 464-8602 Japan
AU: Kimata, F
EM: kimata@seis.nagoya-u.ac.jp
AF: Research Center for Seismology, Volcanology and Disaster Mitigation Nagoya University, Furo Cho Chikusa Ku, Nagoya, 464-8602 Japan
AU: Ito, T
EM: take@seis.nagoya-u.ac.jp
AF: Research Center for Seismology, Volcanology and Disaster Mitigation Nagoya University, Furo Cho Chikusa Ku, Nagoya, 464-8602 Japan
AU: Abidin, H Z
EM: hzabidin@gd.itb.ac.id
AF: Dept. of Geodetic Eng. Institute of Technology Bandung, Jalan Ganesha 10, Bandung, 40132 Indonesia
AU: Kusuma, M A
EM: mipi@gd.itb.ac.id
AF: Dept. of Geodetic Eng. Institute of Technology Bandung, Jalan Ganesha 10, Bandung, 40132 Indonesia
AU: Darmawan, D W
EM: dudy@gd.itb.ac.id
AF: Dept. of Geodetic Eng. Institute of Technology Bandung, Jalan Ganesha 10, Bandung, 40132 Indonesia
AU: Andreas, H
EM: heri@gd.itb.ac.id
AF: Dept. of Geodetic Eng. Institute of Technology Bandung, Jalan Ganesha 10, Bandung, 40132 Indonesia
AU: sugiyanto, D
EM: didiksg2000@yahoo.com
AF: Dept. of Physics, Syiah Kuala University, Darussalam, Banda Aceh, 23111 Indonesia
AU: , A
EM: agustan@tisda.org
AF: Agency for Assessment and Application of Technology, Jalan MH. Thamrin 8, Jakarta, 10340 Indonesia
AB: Site displacements obtained from near-field GPS observation are used to constrain the slip distribution for the December 26, 2004 Sumatra-Andaman earthquake. The existence of pre-event GPS data, collected as control points for land administration, provided a relatively dense coverage close to the rupture area. The maximum horizontal displacement observed was 3m at GPS point located 300km NE of the mainshock. We estimated rupture geometry by using genetic algorithm and constrained least squares for slip distribution. The inversion reveals 3 regions of large slip. The first region is about 100 km from the hypocenter, the slip is more than 20 m. This amount is consistent with reported uplift of Northern Simeulue Island. A second region of large slip, approaching 25 m, is located west of Aceh province. A third patch of 15 to 20 m of slip is located southe west of Nicobar islands. Due to the distribution and geometry of our GPS network we can not resolve the slip around Andaman. The moment magnitude for this estimation is 9.17.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1209 Tectonic deformation (6924)
DE: 7209 Earthquake dynamics (1242)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 8011 Kinematics of crustal and mantle deformation
SC: Union [U]
MN: Fall Meeting 2005