摘要
2021年,云南先后发生漾濞M_(S)6.4、双柏M_(S)5.1及盈江M_(S)5.0地震,3次地震呈短时连发特征。基于云南地区2012-2022年M≥3.0地震震源机制解资料,采用迭代应力反演方法,探讨3次地震前后震源机制一致性参数的空间迁移和时间演化特征。结果显示:应力张量方差在漾濞M_(S)6.4地震区域低值显著,随着时间迁移,向双柏M_(S)5.1地震及盈江M_(S)5.0地震扩展,且2次地震处于低值边缘;3次地震前约1-2年应力张量方差为最低值,小于0.1,震源机制趋于一致,处于应力积累阶段;综合分析认为,在区域应力场反演中,应力张量方差低值与5级以上地震触发有一定相关性,在震情跟踪分析中需加强关注。
In 2021,Yangbi M_(S)6.4,Shuangbai M_(S)5.1,and Yingjiang M_(S)5.0 earthquakes occurred successively in Yunnan Province.The three earthquakes occurred consecutively with short intervals.Based on the focal mechanism data of M≥3.0 earthquakes in Yunnan Province from 2012 to 2022,this paper uses the superimposed stress inversion method to explore the spatial migration and temporal evolution characteristics of the focal mechanism consistency parameters before and after the three earthquakes.The results show that the low value of the variance of the stress tensor is significant in the region of the Yangbi M_(S)6.4 earthquake,which migrates with time and expands to the Shuangbai M_(S)5.1 earthquake and the Yingjiang M_(S)5.0 earthquake,and the two earthquakes are at the edge of the low value region.About 1-2 years before the three earthquakes,the stress tensor variance was the lowest,which was less than 0.1,and the focal mechanism tended to be consistent with the accumulation of stress.Comprehensive analyses concluded that there is a certain correlation between the low value of the stress tensor variance in the regional stress field inversion and earthquakes of magnitude 5 or above,and that it is necessary to pay more attention to this issue in the seismic tracking and analyses.
作者
李见
陈佳
邓佳美
焦港辉
吴谋
LI Jian;CHEN Jia;DENG Jiamei;JIAO Ganghui;WU Mou(Yunnan Earthquake Agency,Kunming 650224,China)
出处
《地震地磁观测与研究》
2025年第2期31-39,共9页
Seismological and Geomagnetic Observation and Research
基金
中国地震局震情跟踪课题(项目编号:CEA-ZQGZ-202501034)
中国地震局监测、预报、研究三结合课题(项目编号:3JH-202401067)
云南省重点研发计划(公共安全专项)(项目编号:202203AC100003)
云南省地震局科技创新团队(项目编号:CXTD202411)。
