Contributions of InSAR to study active tectonics of Taiwan

Presents four case examples of contribution on InSAR to active tectonics issues in Taiwan Island that is one of the most seismically active regions in the world. For these studies, differential InSAR technique is used in a 2-pass approach, the resulting interferograms combine images of the ERS-1/2 satellites from 1993 to 2001. The results illustrate the different tectonic processes that InSAR can investigate in Taiwan: (1) regarding the 1999 Chi-Chi earthquake event, InSAR allows to capture coseismic displacements, and to detect displacements at nearby faults triggered by the earthquake, (2) in the Tainan area (SW Taiwan), InSAR can measure the interseismic crustal deformation field (uplift of an anticline) over eight years, (3) for the Fengshan fault and Longitudinal Valley fault, InSAR is able to monitor fault creep. This study makes it possible to consider InSAR as a tool (in complement to the GPS network) for monitoring several active faults in Taiwan that have the potential to produce earthquakes.