2024年新疆乌什M_(S)7.1地震发震断层产状及其动力学探讨  

Seismogenic Fault Plane and Geodynamic Discussion of the 2024 Wushi M_(S)7.1 Earthquake,Xinjiang,China

作　　者：关兆萱 万永革[1,2] 周明月 王润妍 宋泽尧 黄少华 顾培苑 GUAN Zhao-xuan;WAN Yong-ge;ZHOU Ming-yue;WANG Run-yan;SONG Ze-yao;HUANG Shao-hua;GU Pei-yuan(Institute of Disaster Prevention Science and Technology,Sanhe 065201,China;Key Laboratory of Earthquake Dynamics of Hebei Province,Sanhe 065201,China)

机构地区：[1]防灾科技学院,河北三河065201 [2]河北省地震动力学重点实验室,河北三河065201

出　　处：《地震》2024年第2期1-11,共11页Earthquake

基　　金：国家自然科学基金项目(42174074,41674055,42364005);中央高校科研业务费专项(ZY20215117)。

摘　　要：大地震发生后,断层面产状快速确定对震后趋势判定具有重要参考价值。本文收集2024年新疆乌什M_(S)7.1地震序列的震源机制数据,对多家机构计算的该地震震源机制解进行中心解求解后,对震源机制的节面进行聚类分析,去掉噪声点的震源机制得到两簇结果,发现标准差较小的第二簇中心节面可能为发震断层面。然后,为进一步通过断层面与应力场关系验证可能的发震断层面,收集了该地区历史震源机制资料,反演得到乌什地震震源区的构造应力场,发现该地区受到NW—SE向的挤压应力和近垂直向的拉张应力;将应力场分别投影到两簇节面上,发现标准差较小的第二簇中心节面处于剪应力较大区域,并且正应力也有利于该中心节面破裂。综合其他资料分析,本研究推测2024年新疆乌什M_(S)7.1地震发震断层为NW向、低倾角断层,走向为244.62°,倾角为46.19°。The rapid determination of the seismogenic fault plane after a large earthquake has important reference value for the determination of post-earthquake seismic activity trend.In this study,firstly,the source mechanism data of the 2024 Wushi M_(S)7.1 earthquake sequence in Xinjiang,China were collected,the central solution for multiple source mechanism solutions of the same earthquake are estimated,and the focal mechanism nodal plane clustering analysis are performed.The two clusters are obtained after removing the noise point of nodal plane,in which the cluster with smaller standard deviation may be the seismogenic fault plane of the M_(S)7.1 earthquake.Then,in order to further verify the possible seismogenic fault plane through the relationship of the fault plane and the stress field,we collected the historical seismic source mechanism data in Wushi earthquake source region,and inverted the tectonic stress field.The stress field shows northwest-southeast compressive stress and near-vertical tensile stress.By projecting the stress field onto the two cluster centroid of nodal planes obtained from clustering analysis,it was found that the cluster centroid of nodal planes with less standard error subject larger shear stress,and the normal stress also supports its rupture.Comprehensive analysis with other information,we preferred the seismogenic fault of the 2024 Wushi M_(S)7.1 earthquake is and north-west dipping,low dip angle fault with strike of 244.62°and the dip of 46.19°.

关 键 词：2024年乌什M_(S)7.1地震 震源机制 应力场 发震断层 

分 类 号：P315.7[天文地球—地震学]