利用InSAR资料反演2008年西藏改则M_w 6.4和M_w 5.9地震的断层参数  

Source parameters of the 2008 G(?)rz(?) M_w6.4 and M_w5.9 earthquakes from InSAR measurements

作　　者：冯万鹏[1] 许力生[1] 许忠淮[1] 李振洪 李春来[1] 赵华[1] 

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]Department of Geographical and Earth Sciences,University of Glasgow

出　　处：《地球物理学报》2009年第4期983-993,共11页Chinese Journal of Geophysics

基　　金：中国地震局地球物理研究所院所长基金(018903和016901);科技部973项目(2004CB418404-4);科技部科技支撑项目(2006BAC03B02-02-02);科技部国际合作与交流专项(2008DFA21340)资助

摘　　要：2008年1月9日在我国西藏改则发生了一次M_w6.4地震,随后有40次3.5级以上余震发生,其中最大的一次为1月16 H的M_w 5.9余震.本文处理了ENVISAT ASAR两轨(升轨和降轨)同震资料,精确确定了同震地表位移的空间分布;随后利用弹性半空间的位错模拟确定了上述事件的断层面参数;最后,基于非均匀滑动模型反演确定了两次地震断面上的滑动分布.结果表明,M_w 6.4主震断层为走向218°、倾角52°的西倾断层,最大滑动量约1.9 m,出现在地表以下约7.6 km处;而M_w 5.9余震发生在主震断层西3.2 km的地方,发震断层为走向200°、倾角59°的西倾断层,最大滑动量约1.0m,出现在地表以下约3.9 km处.On 9 January 2008, an Mw6.4 earthquake struck Gerze, Tibet of China, followed by 40 aftershocks with magnitudes equal to or greater than 3.5, including the biggest one with Mw5.9 on 16 January 2008. Two tracks （1 ascending and 1 descending） of ENVISAT ASAR data were processed to precisely determine the locations and amplitudes of coseismic surface displacements firstly. Then the coseismic displacements were inverted to build uniform dislocation models and further distributed slip models in an elastic half-space. The inverted results suggest that the Mw6.4 main shock is associated with a west-dipping fault plane with a strike of 218° and a dip of 52°, while the Mw5.9 aftershock is related with a west-dipping fault plane, 3.2 km west to the main fault, with a strike of 200° and a dip of 59°; and the peak slip of 1.9 m is located at a depth of 7.6 km in the main fault, whilst the maximum slip of 1.0 m is observed at a depth of 3.9 km in the aftershock fault plane.

关 键 词：改则地震 断层参数 INSAR 

分 类 号：P315[天文地球—地震学]