【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。更多还原

【Abstract】 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.更多还原