汶川8.0级地震前龙门山断裂带孕震构造运动特征分析  

Seismotectonic Movement Characteristics of the Longmenshan Fault Zone before the Wenchuan 8.0 Earthquake

作　　者：平建军[1] 江在森[2] 冯向东[1] 平彩鹏 单连君[1] 王夏 

机构地区：[1]河北省地震局,河北石家庄050021 [2]中国地震局地震预测研究所,北京100036 [3]邢台市地震局,河北邢台054001

出　　处：《地震》2014年第1期58-67,共10页Earthquake

基　　金："十一五"国家科技支撑计划子专题(2006BAC01B02-02-02)资助

摘　　要：根据弹性回跳理论,利用1999至2007年相对中国大陆的三期GPS水平运动速度场资料,着重对每一期跨龙门山断裂带的GPS站点运动速度,在平行龙门山断裂带上的投影速度进行计算,在此基础上,以图示和幂函数拟合方式,分析了龙门山断裂带两侧地面相对运动变形情况。结果显示:汶川8.0级地震前龙门山断裂带两侧地面相对运动出现了右旋剪切运动,且这种右旋剪切运动受阻于龙门山断裂带。这对于识别判定孕震弹性应变能积累变形异常,进而开展地震预测与研究具有积极意义。On the basis of elastic rebound theory, using horizontal velocity field of main- land China calculated from GPS data during three observation periods from 1999 to 2007, velocity components that parallel with and plumb to the fault zone are calculated respec- tively in different period, and then relative ground movements of two sides of the fault zone are analysed with power function fitting and graphics. The results show that, the rel- ative ground movement shows right-lateral shear deformation before the Wenchuan 8. 0 earthquake. At the same time, the movement had been locked at the Longmenshan fault zone. So the results have a positive significance for distinguishing elastic strain energy ac- cumulation and deformation anomaly of earthquake preparation, and for further research on earthquake prediction.

关 键 词：龙门山断裂带 GPS 右旋剪切 弹性应变 汶川8.0级地震 

分 类 号：P315.7[天文地球—地震学]