Seismic relocation,focal mechanism and crustal seismic anisotropy associated with the 2010 Yushu M_S7.1 earthquake and its aftershocks

作     者：Bo Zhao Yutao Shi Yuan Gao 

作者机构：China Earthquake Networks CenterBeijing 100045China Institute of Earthquake ScienceChina Earthquake AdministrationBeijing 100036China Institute of GeophysicsChina Earthquake AdministrationBeijing 100081China 

出 版 物：《Earthquake Science》 (地震学报（英文版）)

年 卷 期：2012年第25卷第1期

页      面：111-119页

核心收录：

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：supported by basic research project of Institute of Earthquake Science of China Earthquake Science(No.2009-21) National Natural Science Foundation of China(No.41040034) 

主　　题：Yushu earthquake double difference algorithm focal mechanism shear-wave splitting stress 

摘      要：The 2010 Yushu MsT.1 earthquake occurred in Ganzi-Yushu fault, which is the south boundary of Bayan Har block. In this study, by using double difference algorithm, the locations of mainshock （33.13°N, 96.59°E, focal depth 10.22 km） and more than 600 aftershocks were obtained. The focal mechanisms of the mainshock and some aftershocks with Ms〉3.5 were estimated by jointly using broadband velocity waveforms from Global Seismic Network （GSN） and Qinghai Seismic Network as well. The focal mechanisms and relocation show that the strike of the fault plane is about 125° （WNW-ESE）, and the mainshock is left-laterally strikeslip. The parameters of shear-wave splitting were obtained at seismic stations of YUS and L6304 by systematic analysis method of shear-wave splitting （SAM） method. Based on the parameters of shear-wave splitting and focal mechanism, the characteristics of stress field in seismic source zone were analyzed. The directions of polarization at stations YUS and L6304 are different. It is concluded that after the mainshock and the Ms6.3 aftershock on April 14, the stress-field was changed.