To comprehensively analyze the seismic activity of the East Kunlun Fault Zone from 2009 to 2018,we developed a proced-ure encompassing microearthquake detection,seismic denoising,seismic phase picking,and seismic location to construct a seismic cata-log.We collected continuous waveforms recorded by 20 stations in the eastern segment of the East Kunlun Fault Zone from January 2009 to December 2018.From the 3 198 seismic events listed in the China Earthquake Networks Center(CENC)catalog,we selected 1200 events with clear seismic phases and high signal-to-noise ratios as template events.Using the Graphics Processing Unit-based Match and Locate(GPU-M&L)method,we detected a total of 13,318 earthquake events,including the template events,which is roughly 4.2 times the number of events in the CENC catalog.Next,we employed the neural network-based seismic waveform denois-ing technique(DeepDenoiser)to extract seismic signals from the noise.By examining the time-domain and frequency-domain charac-teristics of noise and seismic signals,we further identified and confirmed 7514 seismic events,approximately 2.3 times the number re-ported by the CENC.The complete magnitude of the detected catalog decreased from ML 1.5,as given by the CENC,to ML 0.9 in this study.Subsequently,we applied the deep neural network-based seismic arrival-time picking algorithm(PhaseNet)to pick the seismic phases.Finally,using the double-difference localization method(hypoDD),we finely located 7247 events.The results show that earth-quakes in the eastern segment of the East Kunlun Fault Zone are linearly distributed or clustered,with focal depths predominantly ran-ging from 0 to 15 km.East of 101°E,the spatial distribution of earthquakes mainly spreads southeastward along the Awancang Fault Zone.Additionally,our results indicate a possible seismic gap in the Maqin-Maqu segment.This study provides an important database for further research on seismic activity and deep seismogenic faults in the eastern segment of the East Kunlun Fault Zone.
关键词
东昆仑断裂/微震检测/匹配定位技术/地震去噪/双差定位
Key words
The East Kunlun Fault Zone/Microearthquake detection/Match and locate method/Seismic denoise/Double dif-ference location
维普
万方数据