Geomagnetic Precursor Anomaly in Fengning Seismic Station before Tangshan Guye M_S5.1 Earthquake

Through the analysis of geomagnetic data of Fengning seismic station from January 1, 2018 to July 15, 2020, it was found that before the Tangshan Guye M_S5.1 earthquake, the accumulation anomaly of magnetic sounding apparent resistivity of Fengning seismic station was found. At the same time, it was found that the Wenan seismic station, the Pinggu seismic station and the Jinghai seismic station had high loading and unloading response ratio anomaly synchronously. On May 31, 2020, the Fengning seismic station, Wenan seismic station, Huangbizhuang seismic station, Changli seismic station and Hongshan seismic station synchronously showed anomalies of daily response ratio. The accumulation anomalies of apparent resistivity of magnetic sounding of Fengning seismic station and that of Daixian seismic station were synchronized with each other. A high loading and unloading response ratio anomaly area around the Capital Circle was formed, and an anomaly area of North China was formed by the anomaly of daily high resistivity. Multiple anomalies, geomagnetic load-unload response ratio, and regional boundary curvature of high value geomagnetic day-to-day ratio indicate a larger earthquake may occur in the Tangshan area, which is consistent with the occurrence of the Tangshan Guye M_S5.1 earthquake.