Variation characteristics of seismicity parameters before strong earthquakes in Sichuan and its neighboring regions

In this paper,based on analyzing the variation characteristics of seismicity parameters prior to 18 groups M≥6 strong earthquakes occurred in Sichuan and its neighboring areas in recent more than 30 years,we conclude that the anomaly of enhancement or quiescence of regional moderate-size earthquake activity can be used as the mid-term indicator for predicting strong earthquakes,and the regional small-size earthquake quiescence can be as the short-term judgment of strong earthquake.Meanwhile,the predicting area can be reduced according to the spatial anomaly distribution of values of A and GL,and combining with the seismotectonic background.