地震地磁观测与研究2025，Vol.46Issue(1)：78-84,7.DOI:10.3969/j.issn.1003-3246.2025.01.011
2017年四川九寨沟MS 7.0地震前地电场优势方位角与小震震源机制解异常一致性分析
Analysis of consistency with anomalous focal mechanisms of small earthquakes and the dominant azimuth of the geoelectric field before the 2017 Jiuzhaigou MS 7.0 earthquake in Sichuan Province
摘要
Abstract
Since both the dominant azimuth of the geoelectric field and the focal mechanism solution of small earthquakes can reflect the direction change of the regional stress field,this paper uses the seepage(movement)model of the geoelectric field tidal wave rock fissure water(charge)to calculate the dominant azimuth of the electric field observation data within 300 km before the 2017 Jiuzhaigou MS 7.0 earthquake in Sichuan,collects the focal mechanism solutions of small and medium-sized earthquakes in the same period in the study area to invert for the regional stress field by the regional stress tensor damping inversion method.The spatial and temporal variation characteristics of the regional stress field inverted by the dominant azimuth anomaly of the geoelectric field and the focal mechanism solution are compared and analyzed.The research results show that before the 2017 Jiuzhaigou MS 7.0 earthquake in Sichuan,the dominant azimuth angle of the electric field in Hanwang,Maqu,Chengdu,and Tianshuitai showed significant changes such as a smaller range,an increase,and a step change.At the same time,the focal mechanism solution of small earthquakes in the study region showed good consistency before the Jiuzhaigou earthquake,but poor consistency afterward.That is,the consistency anomaly of the focal mechanism solution of small earthquakes is consistent with the dominant azimuth anomaly of the geoelectric field in time.This research result has a certain promoting effect on the reliability improvement of the dominant azimuth anomaly of the geoelectric field.关键词
地电场/优势方位角/可靠性/震源机制异常/九寨沟MS 7.0地震Key words
geoelectric field/dominant azimuth/reliability/abnormal focal mechanism/Jiuzhaigou MS 7.0 earthquake引用本文复制引用
鲍海英,夏忠,杨云,李锋..2017年四川九寨沟MS 7.0地震前地电场优势方位角与小震震源机制解异常一致性分析[J].地震地磁观测与研究,2025,46(1):78-84,7.基金项目
地震科技星火计划(项目编号:XH24017YC) （项目编号:XH24017YC）
震情跟踪定向工作任务(项目编号:2023010406) （项目编号:2023010406）
