Relocation of the Foreshocks and Aftershocks of the 2021 Ms 6.4 Yangbi Earthquake Sequence,Yunnan,China  

作　　者：Ting Yang Boren Li Lihua Fang Youjin Su Yusheng Zhong Jingqiong Yang Min Qin Yaji Xu 

机构地区：[1]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China [2]Key Laboratory of Earthquake Source Physics,China Earthquake Administration,Beijing 100081,China [3]Institute of Disaster Prevention,Sanhe 065201,China [4]Yunnan Earthquake Agency,Kunming 650224,China

出　　处：《Journal of Earth Science》2022年第4期892-900,共9页地球科学学刊（英文版）

基　　金：financially supported by National Science Foundation of China(No.41774067);the National Key R&D Program of China(No.2018YFC1503400);the Special Fund of the Institute of Geophysics;China Earthquake Administration(No.DQJB20X07)。

摘　　要：An Ms 6.4 earthquake occurred in Yangbi,Yunnan,China on May 21,2021,which has obvious foreshock activity and abundant aftershocks.Based on the seismic observation data recorded by the Yunnan Seismic Network three days before and seven days after the mainshock,a doubledifference location method was used to relocate 2133 earthquakes of the Yangbi sequence.Aftershocks are mostly distributed to the southeast of the mainshock in a unilateral rupture pattern.This sequence exhibits a SE-trending linear alignment with a length of about 25 km,and most of the focal depth is above 12 km.Integrated with the seismic distribution and focal mechanism results,we infer that the strike of the seismogenic fault is about 140°,and dipping to the SW.The fault structure revealed by the seismic sequence is complex,with the NW segment exhibiting a steep dip and relatively simple structure of strike-slip rupture and the SE segment consisting of several branching ruptures.The Yangbi Earthquake is a typical foreshock-mainshock-aftershock sequence,and the mainshock is likely triggered by the largest foreshock.This earthquake occurred in the boundary between high-and lowvelocity anomalous zone,where is susceptible to generate large earthquakes.

关 键 词：Yangbi Earthquake Weixi-Qiaohou-Weishan fault earthquake sequence double-difference relocation EARTHQUAKES 

分 类 号：P315[天文地球—地震学]