HR: 0800h
AN: S51A-0135    [Abstracts]
TI: Three-dimensional crustal image in the focal region of the 2000 western tottori earthquake using local earthquake and active source data
AU: * Oda, Y
EM: oda-yoshiya@c.metro-u.ac.jp
AF: Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo, 192-0397 Japan
AU: Kitamura, Y
EM: maruionigiri@hotmail.com
AF: Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo, 192-0397 Japan
AU: Abe, S
EM: shintaro@criepi.denken.or.jp
AF: Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba, 270-1194 Japan
AU: Aoyagi, Y
EM: y-aoyagi@criepi.denken.or.jp
AF: Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba, 270-1194 Japan
AU: Iwatate, T
EM: rock-tak@ecomp.metro-u.ac.jp
AF: Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo, 192-0397 Japan
AB: P and S arrival time data from aftershocks of 2000 western tottori earthquake and P arrival time data from active sources or shots have been used in hybrid travel time tomography for hypocenters, three-dimensional Vp and Vp/Vs image in the focal region.The number of aftershocks used in tomography was 1,091 and the number of shots was several hundred. Tomographic image covered a 32 km x 40 km x 16 km area. The grid spacing was flexibly decided according to the density of data. As the results, velocity anomalies were detected in the focal region. Low velocity anomaly that exists around 2 km along the seismic fault would show the activity of the fault in a past. Another anomalies that exist around hypocenter might correlate with asperity.
DE: 0900 EXPLORATION GEOPHYSICS
DE: 0902 Computational methods, seismic
DE: 0910 Data processing
DE: 0935 Seismic methods (3025)
SC: Seismology [S]
MN: 2004 AGU Fall Meeting