地质学报2013，Vol.87Issue(6)：747-758,12.
四川芦山2013年Ms7.0地震发震构造初步研究
Preliminary Study on the Seismotectonics of the 2013 Lushan Ms7.0 Earthquake, West Sichuan
摘要
Abstract
On April 20,2013,an earthquake with a magnitude of Ms7.0 shocked the region of Lushan County,Ya'an City,west Sichuan.The epicenter is located in the zone between Shuangshi and Taiping Townships,with a focal depth of about 13 ～ 14 km.The maximum intensity degree attaincd IX.Although scvcrc destruction of buildings in the shocked area,field investigation did not find obvious co-seismic surface rupture,except a small quantity of grand fissures with sand liquidation.Integrate analysis of high resolution satellite images,main-and after shock distribution and focal mechanism shows that this earthquake is an independent reverse faulting event possibly rupturing the southern segment of the Shuangshi-Dachuan fault,along the SW segment of the Longmenshan fault zone.We infer that the main shock may have occurred on a west dipping ramp (with dipping angle of 33°～43°) of a sole décollement beneath the SW Longmenshan,a similar seismotectonic setting of the Wenchuan earthquake.Historically,there recorded at least two earthquakes with magnitude of Ms 6～6.5 along the Shuangshi Dachuan fault,together with the Lushan earthquake,they characterize the fault activity behavior of this fault zone.Insitu stress measurement results show that this earthquake resulted from the brutal release of accumulated crustal stress within the SW segment of the Longmenshan fault zone.关键词
芦山Ms7.0地震/双石-大川断裂/龙门山断裂带/地裂缝/逆冲断坡Key words
Lushan Ms 7.0 earthquake/ Shuangshi-Dachuan fault/ Longmenshan fault zone/ grand fissure/ reverse ramp引用本文复制引用
张岳桥,董树文,侯春堂,石菊松,吴中海,李海龙,孙萍,刘刚,李建..四川芦山2013年Ms7.0地震发震构造初步研究[J].地质学报,2013,87(6):747-758,12.基金项目
本文为深部探测项目Sino-Probe 08-01资助的成果. （）
