2021年6月10日楚雄双柏M_(S)5.1地震发震断层与序列研判  

An early study on seismogenic faults and sequence trends of the Chuxiong Shuangbai M_(S)5.1 earthquake on June 10,2021

作　　者：茶文剑 金明培[1,2] 高琼 李孝宾[1,2] 黄雅 CHA Wenjian;JIN Mingpei;GAO Qiong;LI Xiaobin;HUANG Ya(Yunnan Earthquake Agency,Kunming 650224,China;China Earthquake Science Experimental Office of Dali Center,Yunnan Province 671000,China)

机构地区：[1]云南省地震局,中国昆明650224 [2]中国地震科学实验场大理中心,中国云南671000

出　　处：《地震地磁观测与研究》2021年第6期28-35,共8页Seismological and Geomagnetic Observation and Research

基　　金：云南省地震局青年科学基金(项目编号:2020K08)。

摘　　要：利用云南区域台网震中190 km范围内方位角均匀分布的9个宽频带数字地震台站波形,采用CAP方法快速反演了2021年6月10日楚雄双柏M_(S)5.1地震及其3个M_(S)≥3.0余震的震源机制解。结果表明,M_(S)5.1主震的震源机制节面Ⅰ:走向301.0°,倾角90.0°,滑动角158.0°;节面Ⅱ:走向31.0°,倾角68.0°,滑动角0.0°,矩震级为M_(W)5.0,矩心深度最佳拟合结果为8.0 km。综合震后M_(L)≥1.0余震的空间展布长轴优势方向和震中周围已知断层分布,判定发震断层面应为节面Ⅱ,震源机制为左旋走滑型地震。另外,依据地震序列衰减h值、余震展布尺度与矩震级匹配程度、矩心深度逐步变浅等综合判定该序列应为主震—余震型。Based on the waveforms of nine broadband digital seismic stations of the Yunnan regional network,which are distributed within 190 km and with a good azimuth coverage,the focal mechanism solutions for the Chuxiong Shuangbai M_(S)5.1 earthquake on June 10,2021,and its three M_(S)≥3.0 aftershocks are rapidly inverted by using the CAP method.The results show that the focal mechanism solution for the M_(S)5.1 mainshock is as follows,the strike,dip,and slip angles are 301.0°,90.0°,and 158.0°for the nodal planeⅠand 31.0°,68.0°,and 0.0°for the nodal planeⅡ,the moment magnitude is M_(W)5.0,and the best-fit centroid depth is 8.0 km.Based on the dominant direction of the long axis of M_(L)≥1.0 aftershocks and the distribution of known faults around the epicenter,it is determined that the seismogenic fault plane is the nodal planeⅡ,i.e.,strike angle 31.0°,dip angle 68.0°,slip angle 0.0°,and it is a left-lateral strike-slip earthquake.In addition,according to the attenuation H value of the seismic sequence,the matching degree of aftershocks distribution scale and moment magnitude,and the gradual shallower moment centroid depth,the earthquake sequence is judged to be the main-aftershock type in the early study,and the possibility of larger earthquakes in the future is low.

关 键 词：2021年6月10日楚雄双柏M_(S)5.1地震 震源机制解 CAP方法 序列地震趋势 

分 类 号：P315[天文地球—地震学]