Investigation on the statistical characteristics of geoelectric field seismic anomalies in the North-South seismic belt of Chinese mainland

Geoelectric field (GEF) measurements have documented many pre-earthquake electromagnetic anomalies over the past few decades. However, the statistical characteristics between earthquakes and GEF are still unclear. In this paper, we use the shifting correlation method to analyze the statistical features of earthquake precursory information in GEF data recorded in the North-South seismic belt of Chinese mainland during 2010-2019. Three factors, seismic energy, epicentral distance (D), and the fault, were used to select the seismic events. In the analysis section, the results of two significance test methods were used as the anomaly standard. The results show that the GEF anomalies associated with seismic events appear about 30 days before the earthquakes, and the anomalies appear earlier at stations farther away from the epicenter. In addition, the selective characteristics of the GEF are strongly correlated with the location of stations and the geological-tectonic environment in which the epicenter is located. Moreover, the results approved the empirical conclusion that the larger the seismic energy is, the larger the impact area is. The statistical characteristics of the seismic GEF anomalies in the North-South seismic belt of Chinese mainland may provide technical support for exploring the phenomenon and mechanism of seismic GEF.