Vol10 No.1: 84-94
【Title】Tectonic Mechanismof the Suining (Ms5.0)Earthquake,Center of Sichuan Basin,China
【Author】ZHOU Rong-jun1,LI Yong2*,Laurence SVIRCHEV3, ZHANG Yong-jiu1, HE Deng-fa4,HE Yu-lin1, ZHAO Pei-lin5, WANG Zan-jun5, LONG Feng1, SU Jin-rong1, WANG Shi-yuan1, LIANG Ming-jian1, LIU Yu-fa1, KANG Chuan-chuan1
【Addresses】1 Earthquake Administration of Sichuan Province, Chengdu 610041, China; 2 National Key Laboratory of Oil and Gas Reservoir Geologyand Exploitation, Chengdu University of Technology,Chengdu 610059, China; 3 Royal Roads University, School of Peace and Conflict Management,Victoria, B.C., Canada; 4 China University of Geoscience, Beijing 100083, China; 5 Earthquake Administration of Chongqing Municipality, Chongqing 401147, China
【Citation】ZHOU Rong-jun, LI Yong, Laurence SVIRCHEV, ZHANG Yong-jiu, HE Deng-fa, HE Yu-lin, ZHAO Pei-lin, WANG Zan-jun, LONG Feng, SU Jin-rong, WANG Shi-yuan, LIANG Ming-jian, LIU Yu-fa, KANG Chuan-chuan. Tectonic Mechanismof the Suining (Ms5.0)Earthquake,Center of Sichuan Basin,China. Journal Of Mountain Science (2013) 10 (1): 84–94. DOI: 10.1007/s11629-013-2504-0
【Abstract】On Jan. 31 of 2010, the Suining earthquake occurred at Suining City which is located the center of Sichuan Basin. It is unusual for the strong earthquake to occur at the center of Sichuan Basin with a stable geotectonic environment and a low-level historical seismicity. The macro-epicenter of the earthquake is located at Moxi town of Suining city，Sichuan province, China. The earthquake intensity of the epicenter area is degree VII, and the long axis of the isoseismal line trends in NE orientation. The Suining earthquake caused the collapse or destruction of 460 family houses. The earthquake focal mechanism solution and records of the near-field seismographic stations showed the earthquake occurred at the reverse fault at a depth 3-4km. Based on the waveform and focal mechanism, we consider the Suning earthquake is triggered by the reverse fault and not by the gravitational collapse or man-made explosive sources. Basing on seismic refraction profile and borehole, we consider that the earthquake is triggered by the back thrust fault of Moxi anticline rooted in detachments at a depth 3-4km.Furthermore,we infer that tectonic mechanism of the Suining (Ms5.0) Earthquake is driven by the horizontal crustal shortening and stress adjustment on a shallow detachment after the Wenchuan (Ms 8.0)earthquake.
【Keywords】Suining (Ms5.0)earthquake; Disaster; Tectonic mechanism; Horizontal crustal shortening; Backthrust fault; Shallow detachment; Sichuan Basin