2020年新疆于田M_(S)6.4地震发震断层及孕震机制研究  

The Earthquake Fault and Seismogenic Mechanism of the Yutian M_(S)6.4 Earthquake in Xinjiang, China in 2020

作　　者：王勤彩[1] 李君 张金川[3] WANG Qin-cai;LI Jun;ZHANG Jin-chuan(Institute of earthquake forcasting,CEA,Beijing 100036,China;The Second Monitoring and Application Center,CEA,Xi'an 710054,China;Earthquake Administration of Jiangsu Province,Nanjing 210014,China)

机构地区：[1]中国地震局地震预测研究所,北京100036 [2]中国地震局第二监测中心,陕西西安710054 [3]江苏省地震局,江苏南京210014

出　　处：《地震》2021年第2期92-101,共10页Earthquake

基　　金：中国地震局地震预测研究所基本科研业务费专项(2020IEF0602);中国地震局三结合课题(3JH-202001030)。

摘　　要：利用2020年6月26日于田M_(S)6.4地震序列的震相和波形数据,对地震序列进行重定位并反演了中强地震的震源机制解,结合2008年至今的全球矩心矩张量解数据,反演了西昆仑块体和柴达木—祁连块体间边界地区的应力场。综合分析研究结果发现:2020年6月26日于田M_(S)6.4地震序列的发震断层为走向SSW,倾向NWW的正断层,地震的发生可能与琼木孜塔格峰山前展布的正断层破裂有关;西昆仑块体和柴达木—祁连块体之间的边界地区属于东西向拉张应力模式,支持青藏高原北部大型走滑断裂所圈定的柴达木—祁连块体的东向运动模型。By the seismic phase and waveform data of the Yutian M_(S)6.4 earthquake sequence occurred on June 26 th,2020,earthquakes are relocated and the focal mechanism solutions of moderate and strong earthquakes are inversed.Using the Global Centroid-Moment-Tensor(GCMT)data from 2008 to present,the stress field in the boundary area between the West Kunlun block and the Qaidam-Qilian block is inversed.The results show that the seismogenic fault of Yutian M_(S)6.4 earthquake sequence on June 26,2020 is a strike-SSW,dipping NWW normal fault,and the occurrence of M_(S)6.4 earthquake may be related to the rupture of normal fault in front of the Ulugh Muztagh mountain.The boundary area between the West Kunlun block and the Qaidamu-Qilian block is in the consistent status with the east-west tensile stress model,which supports the eastward movement model that the Qaidamu-Qilian block delineated by the large strike-slip fault in the northern part of the Qinghai-Tibet Plateau.

关 键 词：发震断层 孕震机制 2020年新疆于田M_(S)6.4地震 

分 类 号：P315.7[天文地球—地震学]