2013年莱州M_(S)4.6地震前电磁异常特征分析  

Analysis of electromagnetic anomaly before the Laizhou M_(S)4.6 earthquake in 2013

作　　者：唐廷梅[1] 盖殿广[1] 李辉[2] TANG Tingmei;GE Dianguang;LI Hui(Shandong Earthquake Agency,Jinan 250100,China;Shandong Institute of Commerce and Technology,Jinan 250013,China)

机构地区：[1]山东省地震局,济南250100 [2]山东商业职业技术学院,济南250013

出　　处：《地震地磁观测与研究》2023年第2期103-111,共9页Seismological and Geomagnetic Observation and Research

摘　　要：收集整理2013年莱州M_(S)4.6地震前山东地磁台和地电场台观测数据,运用地磁垂直分量日变幅加卸载响应比法、地磁总场北京02时测值空间相关法、地磁垂直强度极化法、地电场优势方位角法,提取2013年莱州M_(S)4.6地震前山东出现的电磁异常,分析结果显示:①震前6个月内,泰安、郯城、安丘、陵阳、大山、菏泽等台站分别出现地磁F分量空间相关低值异常以及地磁Z分量加卸载响应比、地磁垂直强度极化值高值异常;②此次地震发生前1年内,距震中较近的乳山地电场台站在长极距NS-EW、NS-NE组合下,方位角出现测值升高—转平—下降的变化过程,并在转平—下降过程中发震。本文采取多方法、多测项相结合的分析手段,对震前异常变化进行梳理和分析,为山东及邻区基于电磁法预测地震积累了经验和震例。This study collects and organizes the observation data of Shandong geomagnetic stations and geoelectric field stations before the Laizhou M_(S)4.6 earthquake in 2013 and uses the method of load-unload response ratio of daily variation amplitude of geomagnetic vertical component,spatial correlation method of measured values at 02 o’clock in Beijing time,geomagnetic vertical intensity polarization method,and geoelectric field dominant azimuth method to extract electromagnetic anomalies that occurred in Shandong before the Laizhou M_(S)4.6 earthquake in 2013.The analysis results show that:①Within 6 months before the earthquake,geomagnetic observations at the stations of Tai’an,Tancheng,Anqiu,Lingyang,Dashan,and Heze show low-value anomalies in the spatial correlation values for the F component and high-value anomalies in the load-unload response ratio and geomagnetic vertical intensity polarization for the Z component;②The combined results of the NS-EW and NS-NE components observed at a long polar distance show that the azimuth angle has changed from rising to leveling and finally declining and the earthquake occurred during the leveling process.This study adopts a combination of multiple methods and multiple observation items to sort out and analyze anomalies before the earthquake and accumulates experience and examples for earthquake prediction using electromagnetic observations in Shandong and its adjacent areas.

关 键 词：加卸载响应比 空间相关 地磁极化 地电场方位角 

分 类 号：P315.721[天文地球—地震学]