Comparison and study on active tectonics environment of strong earthquake swarms;

The article studies 9 strong earthquake swarms of with the magnitude M_S≥6.

Tomographic determination of the upper crustal structure in Jiashi strong earthquake swarm region—joint inversion of explosion and earthquake data;

Focal mechanism of Jiashi strong earthquake swarm and characteristics of the regional stress field;

Using the system cluster of focus mechanism solutions for moderate-strong earthquakes and the stress field inversion of focal region in the Jiashi strong earthquake swarm from 1997 to 1998,main result as followed are obtained:(1) The Jiashi strong earthquake swarm is characterized mainly by strike-slip and normal fault.

We found that,the R value shows mid-long term anomaly before medium-strong earthquake in East China and Anhui area,but mid-long term anomaly in the 100 kilometers area around the Tanlu fault and the joint area of Jiangsu,Shandong,Anhui Provinces which was delimite.

This article deals with a study conducted about the relevance of seismic activities far and near before a mid-strong earthquake in Daxinganling earthquake belt and assists to determine the medium and long-term earthquake prediction.