Disturbance identification of electric field data observed by the CSES-01 satellite before earthquakes  

作　　者：Jianping HUANG Fuzhi ZHANG Zhong LI Xuhui SHEN Baiyi YANG Wenjing LI Zhima ZEREN Hengxin LU Qiao TAN 

机构地区：[1]National Institute of Natural Hazards,Ministry of Emergency Management,Beijing 100085,China [2]Institute of Intelligent Emergency Information Processing,Institute of Disaster Prevention,Langfang 065201,China

出　　处：《Science China Earth Sciences》2023年第8期1814-1824,共11页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 42104159);the APSCO Earthquake Project (Phase Ⅱ);ISSI-BJ International Team (Grant No. 2019-33);Dragon 5 Cooperation Proposal (Grant No. #59308)。

摘　　要：Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by satellites.In this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionospheric electromagnetic disturbance signals were acquired based on the CSES-01 satellite electric field data,and the maximum value of C in the earthquake preparation zones increased continuously from 2.0 three days before the earthquake and reached a maximum weight of 3.0 on the day of the earthquake,after the earthquake,it gradually decreased and recovered to about 2.0;its the C values fluctuated between-2 and 3,it is different from the C values range-2–12 of the previous seismic case study using the DEMETER satellite,which may be related to the orbital altitude and revisit period of the satellite.Then,the C values were normalized,and the time series analysis of the obtained θ values were done,and the results showed that:In the pregnant zone,the background variation of the disturbance amplitude θ is within 2σ,and the maximum disturbance amplitude of θ starts to increase gradually from the seventh period(one period of 5 days,i.e.,35–39 days before the earthquake),it reached 2σ by the fourth preseismic cycle(20–24 days before the earthquake),and then dropped sharply to about 1.5σ in the third pre-seismic cycle(15–19days before the earthquake),after two cycles of increase,the θ over the epicenter reached a maximum of 2.1σ at the time of the earthquake(combining the time of the earthquake and the satellite flight characteristics,the epicenter period is defined as January25-January 29,2020,and this defines the study time period line),and the θ decreases to within 2 times the standard range after the earthquake;The negative value of the disturbance amplitude θ in the central region of the pregnant seismic zone during the earthquake shows the transient energy release process.Through comparison,the θ values obtained by normalization based on the C-value method takes into account the variat

关 键 词：The CSES-01 satellite WHISTLE Electric field C-value method NORMALIZATION 

分 类 号：P315.7[天文地球—地震学]