• 责任者：Lin Xiangdong (Key Laboratory of Seismic Observation and Geophysical Imaging ; Institute of Geophysics ; China Earthquake Administration ; Beijing 100081 ; China) ; Ge Hongkui
• 刊名：Chinese Journal of Geophysics
• 出版年：2013
• 卷期：56(12)
• 关键词：大震 ; great earthquakes ; 余震 ; aftershocks ; 四川 ; Sichuan Province
• 页码：p.4037-4047
• 图表：6 illus., 4 tables, 31 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

     On April 20, 2013, the Lushan magnitude 7.0 earthquake occurred in Sichuan, China. It is the largest earthquake occurred on the Longmen Shah fault since 2008 Wenchuan 8. 0 earthquake. Following the mainshock to date May 5, 52 （ML≥4.0） aftershoeks were recorded by the Sichuan Seismic Network. Based on the previous velocity model results respectively for the Sichuan basin and southeast area, southwest mountain area and northwest mountain area, weanalyzed the broadband waveforms for mainshock and aftershock with sufficient signal-to-noise levels to invert for seismic moment tensors. We finally obtained Lushan mainshock and its 16 aftershock moment tensors with the TDMT_INVC method. We sorted the moment tensors based on the plunge of P, B, and T axes. The results show that： the Lushan earthquakePs magnitude is Mw6.5, Mois0.638X1019Nm, depth is 13 km, and focal mechanism is reverse. The type of the aftershocks is simple and mainly as reverse. The Lushan earthquake sequence distributed at the Penxian-Guanxian fault on southwest end of Longmen Shan fault and the focal mechanisms studied in this study mainly as reverse. This phenomenon indicate that the southwest end of Longmen Shan fault mainly as thrust feature. The similar source feature, short occurrence time interval, and located in the same tectonic structure of the Lushan and Wenchuan earthquake, may suggest they have close relationship with each other.