摘要
使用HASH方法反演了云南亚失稳台网记录的滇西北地区2018年3月—2020年8月期间1338个中小地震震源机制解,震源机制解各参数统计分析和系统聚类结果显示,该区震源破裂以正断层为主,占比57.8%,各类解平均的P轴方位以NNW-SSE和NNE-SSW为主,整体呈近NS向,与云南地区整体的震源机制类型不一致,表现出局部构造影响下的应力场非均匀性。震源机制解一致性参数空间扫描显示,2021年5月21日漾濞6.4级地震发生在一致性参数由低值区向高值区过渡地带,结合速度结构和矩张量反演结果进一步对漾濞地震的发震机理进行了讨论。
The focal mechanism solutions of 1338 small and medium earthquakes recorded by Yunnan sub-instability network from March 2018 to August 2020 were retrieved by HASH method.The statistical analysis of the parameters of the focal mechanism solutions and the systematic clustering results show that the source rupture in this area is dominated by normal faults,accounting for 57.8%.The average P-axis directions of various solutions are mainly NNW-SSE and NNE-SSW,and the whole is near NS direction,which is inconsistent with the overall focal mechanism type in Yunnan area,and shows the non-uniformity of stress field under the influence of local structures.Spatial scanning of consistency parameters of focal mechanism solutions shows that the Yangbi M6.4 Earthquake on May 21,2021 occurred in the transition zone from low to high consistency parameters.Combined with velocity structure and moment tensor inversion results,the seismogenic mechanism of Yangbi earthquake is further discussed.
作者
王晓山
冯向东
赵志远
余海琳
许鑫
WANG Xiaoshan;FENG Xiangdong;ZHAO Zhiyuan;YU Hailin;XU Xin(Hebei Earthquake Agency,Shijiazhuang 050021,China;Institute of Disaster Prevention,Sanhe 065201,China)
出处
《华北地震科学》
2022年第1期46-50,57,共6页
North China Earthquake Sciences
基金
国家重点研发计划项目(2018YFC150330304)。
关键词
滇西北地区
震源机制
系统聚类
震源机制一致性
漾濞地震
northwestern Yunnan
focal mechanism
systematic clustering
consistency of focal mechanism
Yangbi earthquake
