Extract and analysis surface deformation caused by Wenchuan Mw 7.9 Earthquake from InSAR data

On 12 May 2008, a Mw 7.9 Wenchuan Earthquake occurred in Sichuan Province, China, which is located in Longmenshan mountain area with bald relief and dense vegetation. The smaller wavelength (C-band) system can not provide high quality interferograms. In order to map co-seismic deformation in earthquake region, the SAR data collected by L band ALOS/PALSAR sensor of JAXA are used in the study, including before and after the quake from six paths. A two-pass differential InSAR technology and external DEM acquired by SRTM mission are employed in GAMMA software to generate the co-seismic deformation field. GPS observation results of co-seismic deformation surveyed by Chinese national large scientific project-Crustal Movement Observation Network of China (CMONC) project team are used to evaluate the InSAR observations. The result shows that there is a high consistent between GPS and InSAR observations. And accuracy of line of sight surface displacement derived from traditional InSAR technique can achieve cm-level.