Research on the Source Parameters and Scaling Relations of Earthquakes in Qinba Mountain and Its Adjacent Area

Abstract In this paper, the source parameters were determined for 123 small to moderate size earthquakes (1.2 ≤ M L ≤ 4.5) occurred during 1997-2013 in Qinba Mountain and its adjacent area by using the digital seismic data recorded in Shaanxi seismic network. The scaling relations between seismic moment, stress drop, seismic radiated energy with seismic magnitude are determined, the relations between scaled energy E g /M 0 and seismic moment are analyzed. The results show that the seismic stress drop in this area approximately increases with the increase of seismic moment, but the seismic stress drop is generally low. The Zúñiga parameter ε is generally less than 1, indicating partial stress drop mechanism in the region and may be the activity of low strength mature faults. The seismic scaled energy in this area is relatively small, which may be the results of high dynamic friction force or insufficient estimation of seismic radiation energy.