【摘要】 在整合CSN和青海、西藏、四川区域台网宽频带数字地震记录的基础上,采用"Cut and Paste"方法研究了2010年4月14日青海玉树地震序列中M_S4.7级前震、Ms7.1级主震、M_S6.3级强余震的震源机制解和可能的矩心深度,并结合震中附近活动断裂分布与地表破裂带调查资料讨论了发震构造.结果表明2010年4月14日青海玉树M_s 7.1级主震的破裂面为走向129°,倾角84°,滑动角17°,矩心深度6 km左右,矩震级6.8级;Ms4.7级前震的破裂面为走向114°,倾角67°,滑动角5°,矩心深度11 km左右,矩震级4.2级;M_S6.3级强余震的破裂面为走向123°、倾角89°、滑动角9°,矩心深度6 km左右,矩震级5.7级.本次地震序列的发震构造为甘孜一玉树风火山断裂,地震破裂时以左旋走滑为主,地表破裂的总体走向与主震的破裂面走向基本一致,前震-主震强余震的震源性质综合研究可推测发震构造在浅部的倾角陡立,到了深部有所变缓.更多还原

【Abstract】 Based on digital broad-band seismic records of Qinghai,Xizang,Sichuan regional seismic network and CSN,we inversed the focal mechanisms and possible centroid depth of the M_S4.7 foreshock,M_S7.1 mainshock and M_S6.3 aftershock of the Apr 14,2010 Yushu earthquake sequences using the "Cut and Paste"(CAP) method,and analyzed the seismogenic structures combining with the distribution of active faults near the epicenter and filed investigation of surface rupture zone.The Results show that the earthquake surface rupture of the M_S7.1 mainshock is 129°,84°and 17°for strike,dip and rake angles,respectively,the centroid depth is about 6 km and the moment magnitude is 6.8;the earthquake surface rupture of the M_S4.7 foreshock is 114°,67°and-5°for strike,dip and rake angles,respectively,the centroid depth is about 11 km and the moment magnitude is 4.2;The earthquake rupture surface of the M_S6.3 strong aftershock is 123°,89°and 9°for strike,dip and rake angles,respectively,the centroid depth is about 6 km and the moment magnitude is 5.7.The seismogenic structure of the Yushu earthquake sequences is the Ganzi-Yushu-Fenghuoshan fault;the focal mechanism is mainly left lateral strike slip type.The strike of the source rupture plane is basically consistent with the general strike of surface rupture of the M7.1 mainshock.Comprehensive study on the source character of the foreshock-mainshock-strong aftershock indicates that the dip of the seismogenic structure in shallow is vertical and gradually becomes flat in the deep part更多还原