Slip distribution and tectonic implication of the 1999 Chi‐Chi, Taiwan, Earthquake
We report on the fault complexity of the large (M_w = 7.6) Chi‐Chi earthquake obtained by inverting densely and well‐distributed static measurements consisting of 119 GPS and 23 doubly integrated strong motion records. We show that the slip of the Chi-Chi earthquake was concentrated on the surface of a "wedge shaped" block. The inferred geometric complexity explains the difference between the strike of the fault plane determined by long period seismic data and surface break observations. When combined with other geophysical and geological observations, the result provides a unique snapshot of tectonic deformation taking place in the form of very large (>10m) displacements of a massive wedge‐shaped crustal block which may relate to the changeover from over‐thrusting to subducting motion between the Philippine Sea and the Eurasian plates.
© 2001 American Geophysica Union. Received 26 March 2001; revised 03 July 2001; accepted 5 September 2001. We particularly thank S.-B. Yu for offering the GPS observations, M. Simons, J. Saleeby and two anonymous reviewers for comments on this manuscript. This work is supported in part by SCEC contract No. NSF EAR-8920136 and by the U.S. geological Survey under Contract No. 1HQGR0098. Contribution No. 8838, Division of Geological and Planetary Sciences, California Institute of technology, Pasadena, California 91125.
Published - Ji2001p4379_Geophys_Res_Lett.pdf