Possible ELF/VLF Electric Field Disturbances Detected by Satellite CSES before Major Earthquakes
Possible ELF/VLF Electric Field Disturbances Detected by Satellite CSES before Major Earthquakes
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DOI：
10.3390/atmos13091394
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发表时间：
2022-08
期刊：
影响因子：
2.9
通讯作者：
Jiayi Zong;D. Tao;X. Shen
中科院分区：
文献类型：
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作者：
Jiayi Zong;D. Tao;X. Shen
利用卫星CSES上空间电场探测器（EFD）记录的ELF/VLF频段的电场数据，分析了与地震活动相关的异常电磁发射。选取印度尼西亚2019年7月7日的Mw6.9 EQ和7月14日的Mw7.2 EQ两个相邻地震（EQ）作为例子。采用观测和对比分析相结合的方法提取了超低频/超低频波段的电场扰动。本研究结果表明：(1) CSES的电场探测器在两次低纬度强地震的震中附近，即正东北方，探测到ELF/VLF波段显著的电场异常（主要在49 ~ 366 Hz左右）。(2)电场扰动主要在夜间通过卫星CSES探测到，即沿上升轨道。(3)随着频率的增加，这些异常增强会逐渐减弱。(4)电场异常在主震前开始出现在震中东北部，主震后逐渐向震源靠近。与此同时，在第一次地震前，明显的磁共轭特征也逐渐出现，但在下一次地震时逐渐消失。
The electric field data of ELF/VLF frequency bands recorded by space Electric Field Detector (EFD) on satellite CSES were utilized to analyze the abnormal electromagnetic (EM) emission associated with seismic activities. Two adjacent earthquakes (EQ), which are the Mw6.9 EQ on 7 July and the Mw7.2 EQ on 14 July 2019 in Indonesia, were selected as examples. The disturbance of the electric field in the ULF/VLF band was extracted by using observational and comparative analysis methods. The results of this study indicate the following. (1) The significant electric field anomalies in the ELF/VLF band (mainly from about 49 to 366 Hz) were detected near the epicenter, exactly in the northeast, of two strong low-latitude earthquakes by the electric field detector of CSES. (2) The electric field disturbances were mainly detected by satellite CSES over the epicenters at night, i.e., along the scending orbits. (3) These abnormal enhancements will gradually diminish as the frequency increases. (4) The electric field anomalies started to appear in the northeast of the epicenters before the mainshocks and gradually moved closer to the sources after them. At the same time, a clear magnetically conjugated feature also gradually appeared before the first earthquake, but then faded away when approaching the next one.