Stress Change Process Analysis of North China Based on Moderate Seismicity

In this study, we analyze the time series and special distribution characteristic of the moderate M ≥ 4.0earthquakes in north China since the Wenchuan M8.0 earthquake, and then study the stress change process of the north China before and after the Wenchuan M8.0 earthquake and the Japan M_W9.0 earthquake. The result show that the impact of the Wenchuan earthquake on north China is not exceeding Fen-Wei seismic belt, the most significant period is the year of 2010. The Japan M_W9.0 earthquake mainly affected the seismic activity of the Hebei plain seismic belt and the east of the region, in particular, the closer to the plate boundary, the greater the impact is, the most significant period is the year of 2013. Moderate seismicity in north China and its surrounding larger scale structural movement has a certain relationship. Great earthquake occurred in the surrounding of the north China but did not lead to strong earthquake in the area may due to the low level of stress field of the area and the area being in a quiet episode of the fourth earthquake activity period.