关键词: 隐伏断裂, 重复地震, 滑动速率, 北京平原地区

Abstract: Slip rates along the buried faults in Beijing plain area were investigated with the seismic waveform data between 2001 and 2006 recorded by the Beijing Digital Seismic Network.Using cross-correlation analysis of available waveforms,we identified a total of 35 doublets and 20 multiplets that show high waveform similarity.Most of these sequences are aperiodic with recurrence intervals varying from a few minutes to hundreds of days.Given the limited quantity and quality of seismic data in the study area,we have chosen a more robust approach to constrain repeated event locations.The approach incorporates both seismogram similarity by requiring cross correlation threshold and location similarity by requiring differential S-P(dSmP) time between events pairs to be small and minor internal inconsistence in travel time picking at sub-sample precision.The composite selection approach improves the identification of repeating earthquake based on similarity in waveforms.Based on four repeating sequences,we obtained the slip rate about 1.0 ～ 1.2mm/a at seismogenic depths of Hangzhuang-Gaoliying Fault and Nankou-Sunhe Fault,and the slip rate of 1.5mm/a at 9.4km of the south boundary fault of Huai' an Basin,which is consistent with geological and geodetic measurements.

Key words: buried faults, repeating microearthquake, slip rate of fault, Beijing plain area