Detection and analysis of repeating earthquakes in Guanxian- Anxian fault by using waveform cross-correlation

By taking earthquakes from China Earthquake Networks Center catalog as template events，we detected repeating earthquakes down to M_L0.0 from continuous waveforms recorded by 17 portable seismic stations deployed near the Guanxian-Anxian fault through a sliding-window cross-correlation technique. Then，based on double-difference algorithm combined with waveform cross-correlation，243 of the detected earthquakes were relocated. The results indicate that seismicity of Guanxian-Anxian fault became weaker during the studied period. The predominance distribution of focal depth is 5—15 km and the depth profile reveals that focal depth distributes in westward dipping with a high angle. The epicenters of these earthquakes are distributed in NE direction，which coincides with the strike of front-range fault of Longmenshan fault zone. There are differences in seismicity and b value between the northern and southern segments in the studied region，which may be related to regional stress field of the middle segment of Longmenshan fault zone where directions of stress transfer from WNW to ENE from south to north.