Relocated seismicity in Big Beijing area and its tectonic implication
首都圈地震活动构造成因的小震精定位分析

The earthquakes occurred in the studied area from 1980 to 2004 were relocated by the double-difference location method.The relocated seismicity is clearly associated with regional tectonics,and is also in agreement with the existence of deep faults imaged by wide-angle and deep seismic reflection profiling.The vast majority of the earthquakes are located in the upper and middle crust,which implies the two potential seismotectonic mechanisms with deep dynamics and local tectonic blocks motion and deformation.The moderate and strong earthquakes tend to occur in the brittle upper crust and ductile-brittle transition in the lower crust.The seismic activities also demonstrate the pattern of seismic gaps and some potential traces of the steep-inclined buried faults in the Big Beijing area.