2020年古冶MS 5.1地震前后岩石圈磁场变化特征OA

In this paper,the authors summarize the characteristic locations of precursory anomalies of moderate and strong earthquakes with M≥4 in Hebei and its adjacent areas since 2014;combined with the image of H-vector,d-factor,f-total field and 3-factor geomagnetic anomaly changes in the lithosphere magnetic field of the Guye MS 5.1 and Fengnan District MS 4.5 earthquakes,the characteristics of precursor anomalies of the lithospheric magnetic field of Guye earthquake and Fengnan District earthquake are obtained.The results show that:① The 7 M≥4 earthquakes in Hebei and its adjacent areas all occurred in the high-step belt near the"0-value line"of each geomagnetic element of the lithospheric magnetic field,"Near 0-value line",and the characteristic locations of the vector direction of the geomagnetic anomaly;② The Guye MS 5.1 earthquake accords with the characteristics of the spatial location of the precursory anomaly of the lithospheric magnetic field of the medium-strong earthquake in Hebei,with a probability of 75%;③After the Fengnan MS 4.5 earthquake,the anomaly characteristics of the Tangshan lithospheric magnetic field anomaly area were enhanced,and the risk area in situ had the possibility of another earthquake.