HR: 11:50h
AN: S52A-07    [Abstracts]
TI: The Relation between Seismicity and Active Faults in Northwestern Taiwan
AU: * Lee, C
EM: cplee@geps.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, 300 Jung-Da Road, Chung-Li, 320 Taiwan
AU: Tsai, Y
EM: ybtsai@geps.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, 300 Jung-Da Road, Chung-Li, 320 Taiwan
AB: Northwestern Taiwan is a major economical, transportation and cultural center in our country. Geologically, this region is covered by red soil terraces. These terraces are displaced by several active faults. Seismicity reveals potential of strong ground motion in this region. We deploy a microearthquake network to locate the active faults in the region. The aim of our study is to find the characteristics of seismicity in the Taoyuan, Hsinchu, and Miaoli region, and the relation between seiemicity and active faults. The Central Weather Bureau (CWB) in Taiwan has deployed a short period seismic network in whole Taiwan. Many earthquakes were located by the CWB seismic network, but many small mircoearthquakes occurred in the local area can not be detected. Thus we deploy a temporary seismic network in the area since 2001. Ten stations were deployed. Each station includes an accelerograph with GPS and three component velocity-type sensors. The sampling rate is 200 points/sec. There are two ways to increase the accuracy of the earthquake location. One is to increase the seismic stations in the study area. The other way is to improve the location method. We locate the earthquakes by using the data of both CWB seismic network and our seismic network. The results show most earthquakes occurred in the mountain area in the southeast part of the seismic network. After we relocate the earthquakes, the focal depth changes significantly. Most focal depths are less than fifteen kilometers and become densely clustered.
DE: 7230 Seismicity and seismotectonics
DE: 7200 SEISMOLOGY
SC: Seismology [S]
MN: 2004 AGU Fall Meeting