Stress Releasing and Adjusting Progress of Xingtai Earthquake Sequence

In the study, the stress fields of Xingtai earthquake region in different periods is inversed on basis of focal mechnism solutions of the Xingtai earthquake sequence, the analysis of the ocal mechnism solutions and the stress field shows that the earthquake source faults of the Xingtai earthquake sequence are mainly of strike-slip type faults and spread all over the Xingtai earthquake source region. Stress field inversed using the whole sequence are basically consistent with the stress field that inversed using focal mechanism solutions in 3 periods and also consistent with the stress field direction of other strong earthquakes in North China area, which indicates that the occurrence of Xingtai earthquake is in the control of the tectonic stress field of North China. Friction coefficient of the Xingtai earthquake sequence inversed in the stress fields are within the limits of the? Byerlee's law, regional stress field direction is beneficial to fault activity and the frequency and active intensity of earthquake are relatively low which indicate that, the earthquake source region are in a kind of balance and further study on coupling of stress fields statement of deep crust and that of shallow crust is need.t