近年首都圈地区中小地震震源机制解及其特征分析

THE FOCAL MECHANISM SOLUTIONS AND THEIR CHARACTERISTICS FOR MODERATE AND SMALL EARTHQUAKES IN CAPITAL AREA IN RECENT YEARS

摘要: 利用Snoke的初动加振幅比方法和59个3分量数字化测震台站记录到的1028条地震波形资料计算了首都圈地区2002~2004年1月41次中小地震的震源机制解, 并用随机模型等方法对震源机制解的可靠性做了检验。结果表明该区的震源机制具有一定的区域性特征, 如唐山地区以逆断层性质为主, 北京—天津地区以正断层性质为主。

Abstract: Based on the method of initial motion and amplitude-ratio developed by Snoke, the focal mechanisms of 41 moderate and small earthquakes occurred in Capital Area are calculated with 1028 seismic waveform data recorded by 59 three-components digital observatories from 2002 to Jan.2004, And the reliability of the focal mechanism solutions is tested with random model method.The results show that the focal mechanisms in the region have regionality, such as reversal faulting dominates in Tangshan area, and normal faulting dominates in Beijing-Tianjin area.