Authors: Chong Xu Xiwei Xu
Publish Date: 2014/02/22
Volume: 59, Issue: 13, Pages: 1416-1424
Abstract
After the 20 April 2013 Lushan M S 66 earthquake occurred investigation and identification of the seismogenic fault for this event have become a focused and debatable issue This work prepared an initial landslide inventory map related to the Lushan earthquake based on field investigations and visual interpretation of highresolution aerial photographs and provided evidence for solving the issue aforementioned The analysis of three landslidedensity profiles perpendicular to strike direction of the probable seismogenic fault shows that many landslides occurred on the footwall of the Shuangshi–Dachuan fault SDF without sudden change of landslide density near the fault Very few landslides were detected near the Dayi fault DF and also no change of landslide density there While obvious sudden change of landslide density appeared about 1–2 km from the northwest to the western Shangli fault WSF and the landslide density on the hanging wall of the fault is obviously higher than that of on the footwall Therefore we infer that the seismogenic fault for the Lushan earthquake is neither the SDF nor the DF rather probably the WSF located between these two faults which is an evident linear trace on the earth surface Meanwhile the coseismic slip did not propagate upward to the ground implying the Lushan earthquake was spawned by a blindthrustfault beneath the WSFThis work was supported by the National Natural Science Foundation of China 41202235 and 91214201 We thank Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Sichuan Bureau of Surveying Mapping and Geoinformation and Institute of Optics and Electronics Chinese Academy of Sciences for providing highresolution aerial photographs postearthquake We also thank two anonymous reviewers and Profs Peizhen Zhang and Xianglin Gao from Institute of Geology China Earthquake Administration for their helpful comments and suggestions that improved the manuscript
Keywords: