Study on Source Parameters of Earthquakes in Dachang Mining Area

Using the Brune model (1970)and the digital seismic wave data of the earthquake occurred in Dachang mining area,which was recorded by Guangxi Dachang seismic network;we transferred the velocity spectrum into source displacement spectrum.The corner frequency and zero frequency were calculated by using genetic algorithm,further,the source parameters including seismic moment and stress drop were calculated and the relationships among them were analyzed systematically.This paper studies 38 bigger regional earthquakes occurred in this area,the results show that they seismic moments are 2.18×10¹¹~7.89 ×10¹² Nom and rupture radius are 78~439 m,stress drop are 0.01~1.79 MPa.The relations between seismic moment,body-wave magnitude,rupture radius and corner frequency are near log-linear.The distribution of stress drop is dispersed and show little obvious correlation with seismic moment.Dachang mining stress drop values significantly lower,this may be related to the low regional background stress.