HR: 0830h
AN: T21C-0466    [PDF]
TI: Seasonal Surface Deformation In Response To Local Tectonic Activity, Insights From InSAR Observation In The SW Taiwan
AU: * Chang, C
EM: cpchang@csrsr.ncu.edu.tw
AF: Center for Space and Remote Sensing Research, National Central University, No. 300, Rd. Jungda, Chung-Li, 320 Taiwan
AU: Wang, C
EM: ctwang@csrsr.ncu.edu.tw
AF: Center for Space and Remote Sensing Research, National Central University, No. 300, Rd. Jungda, Chung-Li, 320 Taiwan
AU: Chang, T
EM: changty@geps.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, No. 300, Rd. Jungda, Chung-Li, 320 Taiwan
AU: Kuo, C
EM: ckuo@earth.sinica.edu.tw
AF: Institute of Earth Sciences, Academia Sinica, P.O. Box 1-55, NanKang, Taipei, 115 Taiwan
AU: Chen, K
EM: dkschen@csrsr.ncu.edu.tw
AF: Center for Space and Remote Sensing Research, National Central University, No. 300, Rd. Jungda, Chung-Li, 320 Taiwan
AB: In this study we implement the InSAR (Interferometric Synthetic Aperture Radar) technique and correlate with other geodetic observations for the goal of identifying the seasonal surface deformation in the SW Taiwan. The rate of land subsidence in the SW Taiwan area is very fast, especially the Pingtung Plain. It has even been taken highly for the object of natural hazard mitigation. In the first approximation of topography, most of this area exhibits flat relief and covers urban areas or mixtures of nonvegetation and vegetation zones. Thus it is experimentally suitable for C-band InSAR application. Our preliminary interferometric results show that, the regional land subsidence is faster during the dry season, and whereas the subsidence rate is much slower in the raining season. Because land subsidence on local rather than regional scale is frequently caused by the dewatering of sediments, we compare therefore the well log data of this area with our InSAR observations. The result shows that the seasonal variation of subsidence rate is correspondent with the groundwater level fluctuation. Based on our research results, we infer that the compaction resulting in land-surface subsidence occurs as dewatering removes the buoyant support from the sediments. This successful test shows us that with suitable images, the differential interferometry is a useful high-resolution tool for monitoring the earth surface deformation despite the difficulties in a subtropical area with dense vegetation like Taiwan.
DE: 1242 Seismic deformations (7205)
DE: 6924 Interferometry
DE: 7230 Seismicity and seismotectonics
DE: 8015 Local crustal structure
DE: 8040 Remote sensing
SC: Tectonophysics [T]
MN: 2003 Fall Meeting