• 责任者：Chen Chen (Key Laboratory of Petroleum Resource Research ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Xu Yi
• 刊名：Chinese Journal of Geophysics
• 出版年：2013
• 卷期：56(12)
• 关键词：余震 ; aftershocks ; 地震定位 ; seismic location ; 四川 ; Sichuan Province
• 页码：p.4028-4036
• 图表：8 illus., 1 table, 30 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

     Using travel time data from the Sichuan Seismic Network and the double difference relocation algorithm, we determined accurate locations of the Lushan MsT. 0 earthquake and aftershocks. The aim is to determine seismogenic faults and to place constraints on geometry of the fault plane according to the aftershock distribution, and also to analyze aftershock activities. The results indicate that the epicenter of the Lushan MsT. 0 main shock is located at 30.28°N, 102.99°E and its focal depth is 16.33 km. The aftershocks are distributed within a region 32 km long and 15-20 km wide, with depths ranging 5-24 kin. The seismic rupture extends relatively longer to the southwest of the main shock epicenter than that to the northeast. Magnitudes of the aftershocks decrease rapidly with time. Focal depth distributions show a clear thrust rupture within the crust, which is a hidden fault about 10 km east of the Dachuan-Shuangshi fault zone. We estimate that the fault plane has a strike of 217~ and dips to the northwest at 45~ angle, almost parallel to the Dachuan-Shuangshi fault zone only with a gentle dipping angle. Both of them belong to the imbricate thrust system of the Longmengshan range-front fault zone. Affectedby this fault, extend to the zone to the so gap, which is the aftershocks also occurred on the Dachuan-Shuangshil fault zone, parts of which southwestern margin of the Baoxing massif in the northwest. From Baoxing massif uthern end of the Wenchuan Ms8.0 earthquake rupture zone is a 50 km long seismic considered to have a potential risk of a large earthquake in the future.