Dislocation Model for Current Crustal Deformation in and Around Southern Taiwan, China

Abstract

AbstractUsing dislocation model for aseismic deformation and the hybrid global inversion method, the 1990–1995 annually GPS (Global Position System) data from 89 stations in southern Taiwan and its neighboring area are utilized to discuss the origin of the observed deformation field. For the study area, we simply assume six blocks and nineteen fault patches based on the geologic investigation and seismic observation. The inverse results show that the Philippine Sea plate moves at a velocity of (69±2)mm/a in 317° ± 2° relative to the Eurasian plate. About half the rate is concentrated on the Longitudinal Valley fault (LVF), while the other half of the convergence spread over the boundaries among the west blocks. The Philippine Sea plate and the Central Range move toward northwestward. In the west of the Central Range zone, the motion of the blocks accords with the observed fan‐shape distribution of the maximum principal stress. The faults lain between the Western Foothills and the Coastal Plain geological provinces have main thrust components, and the dips turn small from south to north. The fault widths are about 10km and imply they are strongly locked, and most of the historical large earthquakes were occurred here.