Analysis And Research Of Wenchuan Earthquake Zone Based On Gamit/Globk And QOCA

Wenchuan earthquake which occurred in May122008, brought huge human and property lose to the quake zone. The earthquake draws attention again to the study of earthquake monitoring and prediction and earthquake warning.5.12Wenchaun earthquake is a low slip rate earthquake with long recurrence intervals and high breaking strength,which is characterized by slow energy accumulation,long recurrence intervals,large energy release,wide range impact,high breaking strength and heavy secondary disasters.Since this earthquake occurred in the mainland with highly destructive to human society, it is difficult to predict and it is a new type of earthquake worthy of great attention and in-depth study. With the help of CORS earthquake monitoring network,as well as high precision GPS data processing tools, the studying of crustal movement characteristics and crustal deformation make great significance to the disaster reduction and relief work.This thesis calculated the movement characteristics of each CORS station during the earthquake occurring time using the Sichuan province’s monitoring network CORS observation data in may2008,making use of the track module of GAMIT software,.According to the plate constitute of Sichuan region,this,the thesis got the GPS monitoring results during the earthquake occurring time:in the horizontal direction,there is not obvious extraordinary deformation of each station before the earthquake, the dynamic co-seismic deformation characteristics of each site are not identical.it was creeping near the origin when earthquake started,then Chengdu,Jianyang and Mianyang station moved to the northwest; Leshan and Renshou station moved first towards north and then folded to the west;Luzhou,Neijiang,Qionglai and Rongxian station moved towards the northwest; the Pixian station moved towards Northwest and then turned back,the overall direction to the northwest.In the elevation direction,because the height accuracy measured by GPS is relatively bad,it acted as irregular harmonic vibration with relatively large amplitude in the dynamic sequence diagram.Based on the obvious seismic waves arrival time of the GPS dynamic time series and corresponding to the seismic wave propagation law of Chengdu,Mianyang,Pixian and Zhongjiang station’s dynamic time series,studying the seismic wave velocity,the author got the speed of longitudinal wave is about5.061km/s and the speed of transverse wave is about3.389km/s.Using GAMIT/GLOBK software and related softwares,the author got the deformation characteristics of the blocks in Wenchuan earthquake zone before and after the earthquake:Yangzi plate moved to the northwest, Qiangtang palte moved to the east,the displacement monitored by the GPS shows good consistency. According to the analysis with st_filter module of QOCA software, it got consistent result with GLOBK single integrated solution.In the end, this thesis took a brief introduction about the use of the other modules of the QOCA software.