A growing structure near the deformation front in SW Taiwan as deduced from SAR interferometry and geodetic observation

Abstract

We apply the D‐InSAR technique to monitor the active growing structure on the Tainan Tableland near the deformation front in SW Taiwan using ERS SAR images in the period of 1996–2000. Interferometric processing of six SAR images reveals the average slant range displacement (SRD) to be ∼12.5 mm/yr, and it increases from the west edge of the Tainan Tableland and decreases across the Houchiali fault. The GPS campaign data indicate an average horizontal movement of 12 ± 4 mm/yr in the direction of N44°W for the Tainan Tableland with respect to the western coastline. Five precise leveling surveys across the Tainan Tableland over two years show an uplift rate of ∼14 mm/yr for the benchmarks on the Tableland. By combining the horizontal velocity of GPS data and the SRD of D‐InSAR we transfer the SRD into vertical deformation and discuss the deformation pattern and seismic hazards in the Tainan area.