Monitoring Crustal Deformation along the Xianshuihe Fault in the Eastern Tibetan Margin Area with Envisat ScanSAR Interferometry

The Xianshuihe fault of Sichuan province, southwest China, is a highly active strike-slip fault approximately 350 km long. Previous studies have described up to 10-17 mm/yr of left-lateral slip on the Xianshuihe fault during the last decades, as indicated from geological criteria and GPS observations. The satellite InSAR observation is an alternative technique effectively used to measure the crustal deformation on the active fault. However, the conventional strip mode SAR imagery (i.e. ENVISAT/ASAR IM image) covers usually a 100 km wide stripe and will therefore not be sufficient for such large-scale deformation study. In this paper, we presented ScanSAR interferometry applied to ENVISAT/ASAR WSM data to produce about 400times400 km² deformation map over the Xianshuihe fault zone and the Garze-Yushu fault zone. The preliminary stacked deformation results of six WS-WS interferograms indicated a northeast-southwest deformation trend nearly perpendicular to the two fault zones and demonstrated the potential to monitor such wide-stretched deformation using ENVISAT WSS data.