Geological, Topographical, and Seismological Control on the Co-Seismic Landslides Triggered by the 2015 Gorkha Earthquake

摘要

The 2015 Gorkha Earthquake struck Nepal on April 25, 2015 leaving over 22,000 people injured and almost 9,000 people dead in addition to damaging many buildings. The earthquake was also followed by more than 400 aftershocks, the largest of which occurred on May 12, 2015. A major concern was the potential for landslides following the 2015 Gorkha earthquake and its aftershocks. This study details a geospatial landslide database, containing over 4,000 post-Gorkha Earthquake landslides that was developed using high resolution Google Earth images and helicopter surveys conducted during the post-earthquake reconnaissance. The geological, topographical and seismological patterns of the co-seismic landslides are discussed. The results show that the majority of the landslides were observed in the area between the epicenters of the main shock on April 25th and the major aftershock on May 12th with the most landslides observed in the Gorkha, Sindhupalanchowk, and Dhanding districts. Further analysis revealed that most of the landslides occurred in gneiss, migmatite formations followed by those in quartzite materials.