利用张衡一号卫星电场数据研究吉林松原、河北唐山MS5.1地震前后空间电场时空演化特征

利用我国第一颗电磁监测试验卫星张衡一号电场探测仪（EFD）载荷记录到的ULF/ELF频段电场功率谱密度（PSD）数据，限制Dst≥－30 nT和K_p＜3排除空间磁环境扰动后，分4个频段对2020年唐山古冶M_S5.1地震和2019年吉林松原M_S5.1地震前后空间电场时空演化特征进行研究。结果发现，2020年唐山古冶M_S5.1地震4个频段扰动幅度均显示出震前先抬升至最高点超过2倍均方差，而后在下降过程中发震，震后恢复的规律，且第2频段异常尤为明显；4个频段扰动幅度时间序列特征相似，且震前均超过2倍均方差。2019年吉林松原M_S5.1地震不同频段的扰动幅度时间序列特征不同，仅有第2频段超过2倍均方差。2次地震均在第2频段（371~879 Hz）出现震前异常扰动，认为该频段是地震异常提取的优势频段。

Spatio-Temporal Evolution of Electric Field Pre- and Post-Earthquakes Based on the CSES Satellite: MS5.1 Earthquakes in Songyuan,Jilin Province and Tangshan,Hebei Province

To carry out statistical analysis of the spatio-temporal evolution of the electric field during the M_S5.1 earthquakes in Songyuan, Jilin province and Tangshan, Hebei province, we use four frequency bands of the power spectrum density (PSD) data in the ULF/ELF frequency band recorded by the electric field detector (EFD) of the first seismo-electromagnetic satellite-CSES in China with geomagnetic active indexes Dst≥-30nT and K_p<3. The analysis shows that the perturbation amplitudes in the four frequency bands all increased to the high perturbation stage, which reached more than 2 times the standard deviation before the earthquake, and the earthquake occurred during the descent stage during the M_S5.1 earthquake in Tangshan, Hebei province. Then, the perturbation amplitudes recovered, and it was obviously abnormal in the second frequency band. The perturbation amplitudes in the four frequency bands are very similar, and they all reached more than 2 times the standard deviation before the earthquake. The perturbation amplitudes in the four frequency bands are different during the M_S5.1 earthquake in Songyuan, Jilin province. There, only the perturbation amplitude in the second frequency band reached more than 2 times the standard deviation. The perturbation amplitudes of the both earthquakes were obviously abnormal in the second frequency band (371-879 Hz) before both earthquakes, which is considered to be the dominant frequency band for seismic anomaly.