2014年以来云南永善地区M≥4.7地震震源机制解及发震构造  

Focal Mechanism Solutions and Seismogenic Structure of M≥4.7 Earthquakes Since 2014 in Yongshan,Yunnan

作　　者：肖本夫 祁玉萍[1] 龙锋[1] 申源[1] 梁厚朗 田优平 XIAO Benfu;QI Yuping;LONG Feng;SHEN Yuan;LIANG Houlang;TIAN Youping(Sichuan Earthquake Agency,Chengdu 610041,China;Hunan Earthquake Agency,Changsha 410004,China)

机构地区：[1]四川省地震局,成都610041 [2]湖南省地震局,长沙410004

出　　处：《华北地震科学》2020年第3期13-18,共6页North China Earthquake Sciences

基　　金：四川省地震局地震科技专项(LY2007);2019年度震情跟踪定向工作任务(2019010107);中国地震局地震应急青年任务(CEAEDEM201912);国家重点研发计划(2018YFC15045)。

摘　　要：基于Cut-And-Paste(CAP)全波形拟合反演震源机制解方法,利用四川、云南数字地震台网记录的宽频带台站地震波形记录,反演得到2014年以来云南永善3次M≥4.7地震震源机制解及相关参数,并采用双差定位方法对地震序列进行重新定位,最后探讨可能的发震构造。研究结果显示,2014年4月5日M5.3地震的震源机制解属逆冲型地震,2014年8月17日M5.0地震和2019年5月16日M4.7地震均为走滑型地震;结合该区域的地震构造、震后地震烈度分布和余震序列分布,推测2014年以来云南永善地区3次M≥4.7地震及余震的主发震构造为位于莲峰-昭通断裂与峨边-金阳断裂之间的无名断裂,或是莲峰-昭通断裂的前端盲断裂。By using the Cut-And-Paste(CAP) inversion method and the HypoDD method, this paper presents the focal mechanism solutions for 3 M≥4.7 earthquakes and the relocated earthquake sequence information in Yongshan region on the basis of broadband seismic wave records from Sichuan and Yunnan digital seismic network. The results of 3 earthquakes show that the focal mechanism solution type of M5.3 earthquake on April 5, 2014 is thrust. The focal mechanism solution types of M5.0 earthquake on August 17, 2014 and M4.7 earthquake on May 16, 2019 are strikeslip. Combining with the regional seismotectonic analyzing and the spatial distribution of seismic epicenter and seismic intensity for the 3 earthquakes, the main seismogenic structure of the 3 earthquakes and aftershocks is an anonymous fault located between the Lianfeng-Zhaotong fault and Ebian-Jinyang fault, or the frontal blind fault of the LianfengZhaotong fault.

关 键 词：永善地震 震源机制解 发震构造 CAP方法 

分 类 号：P315.6[天文地球—地震学]