Seismic Activity Research On Longmen Mountains Fault Zone Post-Wenchuan Earthquake

The violent Wenchuan earthquake occurred on May 12, 2008, which shocked the whole china, and even affected half Asia. Wenchuan earthquake’s seismogenic fault is located in Longmen Mountains’fault zone of the east edge of Qinghai-Tibet Plateau, with magnitude 8.0, the maximum intensity 11, more than 70,000 aftershocks, the largest aftershock magnitude 6.4, and the aftershock area length 300km and width 80km. And the earthquake caused very serious secondary disasters. Wenchuan earthquake,in 30 years,is a powerful earthquake, and it is the most destructive, with the widest affecting scope and the most complicated rescue. The devastating Wenchuan earthquake hit China, killing nearly 80,000 people, injuring 370,000 and leaving over 45,00 0,000 people homeless and about one trillion yuan property loss. This disaster made china weep, the whole country with the grief, and shocked the world. After the earthquake,“Wenchuan seismic fault zone scientific drilling program”, proposed by Ministry of Science and Technology, Ministry of Land and Resources, and China Earthquake Administration, was immediately supported and approved by Premier Wen Jiabao, Vice Premier Li Keqiang and Hui Liangyu.The paper relies on two research projects (“borehole scientific probe”and“the stress environment, strain energy distribution of seismic fault zone and their relationship with earthquakes”) presided by the Institute of Geomechanics of Chinese Academy of Geological Science,and these two projects are included in the National Technology Support Project“wenchuan seismic fault zone scientific drilling program”. Through these seismic data derived from the network of seismographic station located in Longmen Mountains fault zone (the seismographic station is designed and fixed independently by the Institute of Geomechanics), Qingchuan fault zone’s stress measure data, and the detection to the‘5.12’wenchuan earthquake’s aftershocks, meanwhile integrating the previous research on Longmen Mountains, and from fault activity analysis, seismic activity hazard analysis, the regional tectonic stress field analysis and the current tectonic deformation analysis, I did comprehensive analysis to the seismic activity characteristics of Longmen Mountains fault zone.Major work goes as follows: 1、Collecting and analyzing the historical earthquake basic data of Longmen Mountains fault zone. Studying on faults’characteristics of working region, including active faults’structural composition, spatial occurrence, active time, movement velocity, and seismic activity, etc.2、Participating in real-time seismic data processing, and the designing, fixing, and testing to the seismographic station of Longmen Mountains, presided by researcher Penghua et al of the Institute of Geomechanics of Chinese Academy of Geological Science.3、Participating in hydrofracturing stress measurement nearby Qingchuan fault presided and carried out by the Institute of Geomechanics of Chinese Academy of Geological Science, obtaining the value, direction, and distribution characteristics of the tectonic stress of the upper wall and foot wall, and by use of Coulomb friction-slide criterion analyzing and evaluating to this fault’s stability.