Co-seismic landslides induced by the 2008 Wenchuan magnitude 8.0 Earthquake, as revealed by ALOS PRISM and AVNIR2 imagery data

Abstract

The magnitude 8.0 Wenchuan Earthquake occurred on 12 May 2008 in Sichuan Province, China, resulting in numerous landslides along the marginal zone between the Tibetan Plateau and Sichuan Basin. We used Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) and Advanced Visible and Near Infrared Radiometer type 2 (AVNIR 2) data from the Advanced Land Observing Satellite (ALOS) and Landsat Enhanced Thematic Mapper (ETM) images acquired before and after the earthquake to identify co-seismic landslides. Interpretations of remote sensing images, combined with fieldwork, reveal that co-seismic landslides are mainly restricted to a corridor of <18 km in width about the co-seismic surface rupture zone along a length of >285 km along pre-existing active faults of the Longmenshan Thrust Belt. The landslides mainly occurred upon steep slopes (dips of 30–75°). The distribution and topographic features of co-seismic landslides indicate a close relationship with seismic slip along the co-seismic surface rupture zone. The locations of landslides are controlled by the tectonic topography developed along pre-existing active faults of the Longmenshan Thrust Belt. Our results demonstrate that remote sensing techniques provide a powerful tool for identifying co-seismic landslides produced in intermountain regions by strong earthquakes.