2011年3月10日云南盈江M_(S)5.8地震的微震匹配定位与发震机理研究  

Match and locate for small event detection of the Yingjiang M_(S)5.8 earthquake on March 10,2011,and investigation of its seismogenic mechanism

作　　者：王晓 周振贵 叶青[1] 黄经国[1] 王亚璐 余丹[1] 王军[1] WANG Xiao;ZHOU Zhengui;YE Qing;HUANG Jingguo;WANG Yalu;YU Dan;WANG Jun(China Earthquake Networks Center,Beijing 100045,China;Anqing Seismic Station of Anhui Province,Anqing 246001,Anhui,China;Institute of Earthquake Forecasting,CEA,Beijing 100036,China)

机构地区：[1]中国地震台网中心,北京100045 [2]安徽省安庆地震台,安徽安庆246001 [3]中国地震局地震预测研究所,北京100036

出　　处：《地震工程学报》2022年第5期1185-1191,共7页China Earthquake Engineering Journal

基　　金：中国地震台网中心青年科技基金课题(QNJJ201813)。

摘　　要：前震序列分析在主震成核过程研究中具有重要意义。为探讨2011年3月10日盈江M_(S)5.8地震孕震发震机理,利用微震匹配定位技术(Match and Locate),以92个M_(S)≥2.0的地震事件作为模板事件,对主震区周围5个台站连续地震记录进行前震检测,并结合前震、余震分布特点和主震前、后b值变化趋势等开展综合分析。结果显示,盈江M_(S)5.8地震前震主要集中于大盈江断裂第一分支西侧,余震沿ENE、SSE两个优势方向展布,推测此次盈江M_(S)5.8地震的主要动力学成因系印度板块的持续向东挤压致使ENE向的大盈江断裂和SSE向的隐伏断层构成的共轭断层系统发生破裂导致;主震前、后b值变化暗示腾冲火山区下方广泛存在的流体在此次地震孕育发生过程中起到重要的诱发和促进作用。The analysis of foreshock sequences is of great significance in the study of the nucleation process of the mainshock.To explore the seismogenic mechanism of the Yingjiang M_(S)5.8 earthquake on March 10,2011,the match and locate(M&L)method for small events was used to analyze the continuous seismic records of five stations around the mainshock.A total of 92 seismic events with M_(S)≥2.0 were selected to perform the foreshock detection and enrich the foreshock catalog.Then,combining the distribution characteristics of foreshocks and aftershocks with the b value change trend before and after the mainshock,a study on the seismogenic mechanism of the Yingjiang M_(S)5.8 earthquake was conducted.The results show that the foreshocks of the Yingjiang M_(S)5.8 earthquake mainly occurred on the west side of the first branch of the Dayingjiang fault,and the aftershocks spread in two dominant directions of ENE and SSE.Based on inferences,the Yingjiang earthquake was caused by the rupture of a conjugate fault system consisting of the ENE-trending Dayingjiang fault and an SSE-trending blind fault due to the continuous eastward extrusion of the Indian plate.The change in the b value before and after the mainshock suggests that the fluids widely existing under the Tengchong volcanic area play an important role in inducing and promoting the occurrence of the earthquake.

关 键 词：M&L微震匹配定位技术 前震 余震 B值 大盈江断裂 流体 

分 类 号：P315.2[天文地球—地震学]