The Present-Day Tectonic Setting of Taiwan Based on an Analysis of GPS and Seismological Data.

We inverted 143 GPS velocity vectors at Taiwan for strain and rotation rates and relative motion on faults. By a joint interpretaion of the crustal deformation field and other geophysical data and models (e.g. seismicity, tomography) we derived a model for the tectonic setting of Taiwan. We determined significant lateral extrusion in both northern (to the NE) and southern Taiwan (to the S), separated from the central area by two major seismogenic transfer fault zones. The rapid uplift and NE-SW extension in the Central Range are inferred to result from exhumation of the forearc block. At Hualien, a southward propagating tear fault has develloped along the outer boundary of the Luzon arc and incipient subduction of the Phillipine Sea Plate to the WNW has commenced at its northern tip. Thus a new trench is develloping southward along the eastern coast of Taiwan.