2007年宁洱6.4级地震横波分裂研究  

Study on the Shear-wave Splitting of the 2007 Ning'er,Yunnan,M_S6.4 Earthquake Sequence

作　　者：毛慧玲[1] 秦嘉政[1] 

机构地区：[1]云南省地震局,昆明650224

出　　处：《地震研究》2011年第1期42-46,共5页Journal of Seismological Research

基　　金：云南省十项措施"云南强震活动与板缘动力学机制研究(JCYB-20080601-4)"与"地球物理场和化学场动态变化与强震活动关系研究(JCYB-20080601-5)"联合资助

摘　　要：通过研究2007年6月3日宁洱MS6.4地震余震序列的三分向记录,为探索横波分裂现象以及上地壳存在裂隙各向异性提供依据,并发现快速S波偏振有两个优势方向,分别为NW140°和NW150°,这与宁洱地区的主应力场方向基本一致。横波分裂延迟时间能够动态反映地下应力场的变化趋势,且较大余震发生之前延迟时间出现大幅度上升。In this paper,the result of the study about the aftershock-swarm of the MS6.4 earthquake occurred on June 3,2007 in Ning＇er,Yunnan Province was given and the existence of both shear-wave splitting and the extensive dilatancy anisotropy in the upper crust of Ning＇er region were recognized.The fast shear wave has two preponderant polarization-directions—NW140°and NW150°,which agree with the regional principal compressive stress.The delay time of the shear wave dynamically responds to the variation of stress field and increases before strong aftershocks.

关 键 词：横波分裂 裂隙各向异性 延迟时间 宁洱地震 

分 类 号：P315.31[天文地球—地震学]