Abstract: Based on the seismic waveform data from 2005 to 2016 in the border area of Shanxi-Hebei-Shandong-Henan provinces recorded by Handan Seismic Network, apparent stress values of 302 small and moderate earthquakes (2.0≤M_L<4.3) were calculated using near-surface Brune model and genetic algorithm. The range of apparent stresses of Shanxi-Hebei-Shandong-Henan border area is 0.01—3.26 MPa, with an average of 0.535 MPa. The scaling relationship between source parameters is discussed. The spatial and temporal characteristics of stresses are analyzed. The results show that there are some obvious high values of apparent stress and stress anomalies in many areas at the border area of Shanxi, Hebei, Shandong and Henan Provinces. The earthquakes mostly occur in the area of high apparent stress anomaly and its vicinity, and high apparent stress anomalies occurred before the majority of earthquakes. The results indicate that the abnormal high apparent stress give some indication to the prediction of the epicenters of moderate to strong earthquakes, which can be used as the basis of earthquake risk judgment at the border area of Shanxi, Hebei, Shandong and Henan.

Key words: Seismic source dynamics, Apparent stress, The border area of Shanxi, Hebei, Shandong and Henan provinces