2011年日本9.0级地震前后应力场变化  

The change of stress field before and after Japan M 9 earthquake in 2011

作　　者：李姜[1] 万永革[2] Li Jiang;Wan Yongge(Hebei Earthquake Agency,Shijiazhuang 050021,China;Institute of Disaster Prevention Sanhe,Hebei Province 065200,China)

机构地区：[1]河北省地震局,中国石家庄050021 [2]防灾科技学院,中国河北065200

出　　处：《地震地磁观测与研究》2018年第3期45-51,共7页Seismological and Geomagnetic Observation and Research

基　　金：河北省地震局地震科技星火计划青年课题(项目编号:DZ20170508024);河北省地震局地震科技星火计划重点课题(项目编号:DZ20160621077)

摘　　要：通过对2011年日本9.0级地震前后不同时段震源机制解进行分析,利用FM_SI震源机制反演法求解,得到此次地震前后内陆地区的应力场。研究发现,此次地震发生前,应力场比较均衡稳定,挤压应力接近水平向,而拉张应力比较复杂,方向不确定,表明该地区的地震以逆断层和走滑为主。地震发生后,日本东北地区东南部应力场变得不太稳定,该地区地震以正断层为主,最小挤压应力由垂向转变为水平向。此研究结果可以用来分析该地区地震地质背景和断层形成条件,对地球动力环境研究具有一定参考意义。Based on the analysis of focal mechanism in different periods before and after Japan M 9 earthquake in 2011, the stress field in the inland area before and after Japan M 9 earthquake was obtained by using the FMSI focal mechanism inversion method. Before the earthquake, the stress field is relatively stable and the compressive stress is near the horizontal level. The tensile stress is more complex and the direction is uncertain, indicating that the earthquakes in the area are mainly reverse fault and strike slip. After the earthquake, the stress field in the southeastern part of northeast Japan changed and became unstable. The normal fault is the main cause of the earthquake, and the minimum extrusion stress has changed from vertical to horizontal. The results of the study can be used to analyze the seismic geological background and fault formation conditions in this area, and have some reference and significance for the study of the earth＇s dynamic environment.

关 键 词：日本9.0级地震 震源机制解 应力场 

分 类 号：P315.727[天文地球—地震学]