汶川地震和芦山地震对青藏高原东缘主要活动断层应力变化的影响  

Effects of Wenchuan and Lushan Earthquakes on the Changes of Stress of Main Active Tectonics in the Eastern Edge of Qinghai-Tibet Plateau

作　　者：熊林[1,2] 何建坤[1] 潘正洋[1,2] 周云[1,2] 刘玉琳[3] 

机构地区：[1]中国科学院青藏高原研究所,北京100101 [2]中国科学院大学,北京100049 [3]北京大学地球与空间科学学院,北京100871

出　　处：《地球科学与环境学报》2014年第3期113-122,共10页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(40774050;41030320)

摘　　要：根据弹性无限半空间位错理论,结合汶川地震和芦山地震的同震破裂模型,以及该地区活动断层几何学和运动学特征,应用Coulomb程序,计算了2008年汶川地震静态库仑应力变化,并和余震分布特征进行对比;同时,计算了2008年汶川地震和2013年芦山地震共同作用产生的静态库仑应力变化,并将结果投影到青藏高原东缘主要活动断层上。结果表明：汶川地震产生的余震大部分分布在其造成的静态库仑应力增加区;汶川地震在芦山地震震中区域产生的静态库仑应力显著增加,增加值为0.010-0.050MPa,汶川地震产生的静态库仑应力变化使得芦山地震提前到来;鲜水河断裂北部、东昆仑断裂、秦岭南缘断裂西段、青川断裂东段、茶坝—林庵寺断裂西段、灌县—江油断裂、大川—双石断裂的静态库仑应力均有不同程度的增加;岷江断裂、虎牙断裂、汶川—茂县断裂、江油—广元断裂、鲜水河断裂南部的静态库仑应力有不同程度的降低;考虑到青藏高原东缘历史大地震和余震分布情况,未来应加强对鲜水河断裂西北段和东昆仑断裂地震危险性的监测与研究。According to the dislocation theory in elastic infinite half-space and the geometric and kinematic characteristics of active faults,based on the coseismic rupture models of Wenchuan and Lushan earthquakes,changes of static Coulomb stress induced by Wenchuan earthquake in 2008 were calculated by Coulomb software,and were compared with the distribution of aftershocks;changes of static Coulomb stress jointly induced by Wenchuan earthquake in 2008 and Lushan earthquake in 2013 were calculated,and were projected onto main active tectonics in the eastern edge of Qinghai-Tibet Plateau.The results show that most of aftershocks occur in the increase area of static Coulomb stress induced by Wenchuan earthquake;static Coulomb stresses induced by Wenchuan earthquake increase 0.010-0.050 MPa significantly in the epicenter area of Lushan earthquake,and change of static Coulomb stress induced by Wenchuan earthquake leads to theearlier occurrence of Lushan earthquake;static Coulomb stresses of the northern part of Xianshuihe,East Kunlun,the western segment of Qinling southern frontal,the eastern part of Qingchuan,the western part of Chaba-Lin＇ansi,Guanxian-Jianyou and Dachuan-Shuangshi faults increase at different levels;static Coulomb stresses of Minjiang,Huya,Wenchuan-Maoxian,JiangyouGuangyuan and the southern part of Xianshuihe faults decrease at different levels;considering the distribution of historical great earthquakes and their aftershocks in the eastern edge of Qinghai-Tibet Plateau,monitor and research on the seismic risk in the northwestern part of Xianshuihe fault and East Kunlun fault should be strengthened in future.

关 键 词：地震触发 汶川地震 芦山地震 静态库仑应力 数值模拟 鲜水河断裂 东昆仑断裂 青藏高原 

分 类 号：P315.2[天文地球—地震学]