Abstract:On the basis of precise locations of the Wenchuan earthquake sequence by using the HYPODD method, the focal mechanisms of the aftershocks (M5.0) occurred on the Longmenshan fault zone north to Beichuan were inversed by using the CAP method and the characteristics of hypocenter distribution and rupture complexity of strong aftershocks are discussed. The results are that the focal depth of Wenchuan aftershock sequence decreased gradually from Yingxiu of Wenchuan to Nanba of Pingwu along Longmen Shan fault zone, which beyond the segment boundary located in Beichuan, and the epicenters were distributed along the YingxiuBeichuanNanba coseismic surface rupture zone in the Central Fault. The aftershock sequence was characterized as less secondary segmented activity in Central Fault Zone north to Beichuan. The aftershocks (M≥5.5) were occurred on the end, transition or dislocation of the aftershocks zone. According to the focal mechanism, four of the seven stronger aftershocks are thrust and the others are strikeslip, it may suggest that the process of the aftershock activity was related to the BeichuanQingchuan Fault, PingwuQingchuan Fault etc.
Lü Jian ,Wang Xiaoshan ,Miao Chunlan et al. ON CHARACTERISTICS OF HYPOCENTER DISTRIBUTION AND RUPTURE COMPLEXITY OF WENCHUAN AFTERSHOCK SEQUENCE ALONG LONGMENSHAN FAULT ZONE NORTH TO BEICHUAN[J]. jgg, 2012, 32(5): 17-21.