2021年漾濞M_(S)6.4地震地下面电流计算研究  

Research on Calculation of Underground Surface Current during 2021 Yangbi M_(S)6.4 Earthquake

作　　者：孙君嵩 王丽 袁桂平[1] 章鑫 李鸿宇[1] SUN Junsong;WANG Li;YUAN Guiping;ZHANG Xin;LI Hongyu(Jiangsu Earthquake Agency,3 Weigang,Nanjing 210004,China;Guangdong Earthquake Agency,81 Mid-Xianlie Road,Guangzhou 510070,China)

机构地区：[1]江苏省地震局,南京市210014 [2]广东省地震局,广州市510070

出　　处：《大地测量与地球动力学》2025年第1期91-96,共6页Journal of Geodesy and Geodynamics

基　　金：中国地震局地震科技星火计划(XH22001YC);国家自然科学基金(42274107);中国地震局地震预测研究所基本科研业务专项(CEAIEF20220207);中国地震局震情跟踪定向工作任务(2024010406);江苏省地震局局长基金(202201)。

摘　　要：以区域固定地磁台站观测数据为基础,定量研究2021-05-21漾濞M_(S)6.4地震前川滇地区出现的地磁日变化空间相关异常现象,并基于毕奥-萨法尔定律和蒙特卡洛模型反演地下电流的分布状态和深度。结果显示:1)研究区域下方存在2处高导带,位置与前人给出的地壳流位置相对应;2)研究区域下方既存在横向界面的不均匀性,也存在纵向界面的不均匀性,面电流的分布可能与构造活动有关;3)热物质上涌可能是地下电流集中分布现象产生的原因之一。Based on the observation data from regional fixed geomagnetic stations,this study quantitatively investigates the large-scale geomagnetic daily variation anomalies that occurred in the Sichuan-Yunnan region before the Yangbi M_(S)6.4 earthquake on May 21,2021.This article is based on Biot-Savart’s law and the Monte-Carlo model to invert the distribution state and depth of underground current.The results show that:1)The spatial distribution position and depth of underground current are consistent with the distribution of underground electrical high conductors,which is consistent with the crustal current position given by previous studies.2)There is non-uniformity in both the horizontal and vertical interfaces below the research area,and the distribution of surface currents may be related to tectonic activity.3)The upwelling of deep thermal fluids may be one of the reasons for the concentrated distribution of underground currents.

关 键 词：地磁日变化 地下电流 地质构造 电性结构 

分 类 号：P315[天文地球—地震学]