HR: 10:40h
AN: T32C-02    [Abstracts]
TI: Interseismic crustal deformation of Taiwan: A new insight with constraints of block model on 7-year GPS results
AU: * Chuang, R Y
EM: b86208026@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan
AU: Miller, M
EM: meghan@cwu.edu
AF: Department of Geological Sciences, Central Washington University, 400 E. University Way, Ellensburg, WA 98926, United States
AU: Shyu, J H
EM: jbhs@gps.caltech.edu
AF: Dpt. Geo- and Environmental Sciences, Ludwig-Maximilians U, Luisenstr 37, Munich, 80333, Germany
AU: Chen, Y
EM: ygchen@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan
AB: The island of Taiwan lies at the junction of the Eurasian and Philippine Sea plates. The convergence between these two plates forms the Longitudinal Valley, which has long been regarded as one of the major collisional suture zones, to the east and a fault-and-thrust belt to the west across the island. Based on recent published geological map and relevant studies, several major active faults are currently acting in Taiwan. In eastern Taiwan, the Longitudinal Valley fault, the most dominant fault within the suture zone, is locked along the northern section and is creeping at shallow depth but locked at deeper part in the southern section. In western Taiwan, active faults imbricate and propagate to the west above a proposed major Taiwan detachment Lots of the active thrust faults and tear faults in western Taiwan are seismogenic. The locking and creeping of the active faults around Taiwan as well as the locking of the subduction zones along the Ryukyu and Manila Trenches constrain the interseismic deformation across the Taiwan region and accumulate strain which may be released during future large earthquakes. In order to characterize interseismic deformation around Taiwan region, we analyze GPS data from 1990-1997. This time span excludes the effects of large earthquakes in the century, especially the Chi-Chi earthquake of 1999. For better understanding interseismic coupling and fault slip, we construct a three-dimensional block model across the Taiwan region to quantify kinematically consistent estimates of block motions and fault slip rates. The model combined elastic half-space and block motions based on the backslip model to describe the GPS velocities and locking faults. The GPS constrained block model provides estimates of present-day fault slip rates and seismic potential within the entire Taiwan region.
DE: 8020 Mechanics, theory, and modeling
DE: 8100 TECTONOPHYSICS
SC: Tectonophysics [T]
MN: 2007 Fall Meeting