地震地磁观测与研究2023，Vol.44Issue(5)：95-106,12.DOI:10.3969/j.issn.1003-3246.2023.05.012
2021年12月22日常州ML4.6地震前地电阻率异常分析
Analysis of ground resistivity anomaly before the Changzhou ML 4.6 earthquake on December 22,2021
摘要
Abstract
Nanjing Seismic Station,Jiangning Seismic Station,Gaoyou Seismic Station,Guzhuang Seismic Station,and Sangzhou Seismic Station in Jiangsu Province showed relatively consistent stress changes before the Changzhou ML 4.6 earthquake on December 22,2021.The sliding Fourier spectrum of the NS-direction earth resistivity at each seismic station showed significant pre-earthquake anomalies.In order to verify the reliability of the anomalies,the following work was carried out:firstly,the empirical formula suitable for Jiangsu Province for the maximum epicenter distance Δmax of detectable earth resistivity anomalies and earthquake intensity M is obtained by the method of collecting historical earthquake cases related to the changes of earth resistivity anomalies in Jiangsu Province and its adjacent areas:lgΔmax = 1.0861 + 0.2624 M.When the epicenter distance is Δ,the earthquake with M>(lgΔ-1.0861)/0.2624 is defined as a significant earthquake,which can cause abnormal variations in earth resistivity.Then the correlation analysis between abnormal variations of ground resistivity after eliminating the annual trend and the significant earthquakes around the seismic station is carried out.The analysis results show that there is a good correlation between the earth's resistivity variations and significant earthquakes.It is relatively stable in quiet periods of seismic activity and fluctuates or shows declining changes greatly before significant earthquakes.The abnormal variations are more obvious before stronger seismic activities,such as the Sheyang ML 4.8 earthquake on October 20,2016,the South Yellow Sea ML 5.5 earthquake on November 17,2021,and the Changzhou ML 4.6 earthquake on December 22,2021.Therefore,the anomalous changes in ground resistivity before the Changzhou ML 4.6 earthquake at the Nanjing,Jiangning,and Gaoyou seismic stations,as well as the Guzhuang and Sangzhou seismic stations,are true and reliable.关键词
常州ML4.6地震/地电阻率异常/最大可探测距离/显著地震/去年变分析Key words
Changzhou ML 4.6 earthquake/ground resistivity anomaly/maximum detectable distance of ground resistivity/significant earthquake/eliminate annual change引用本文复制引用
张贵霞,沈红会,王丽,杨从杰,王昕,袁慎杰..2021年12月22日常州ML4.6地震前地电阻率异常分析[J].地震地磁观测与研究,2023,44(5):95-106,12.基金项目
地震科技星火计划(项目编号:XH211003) （项目编号:XH211003）
