苏北测震台网地面和井下地震记录波形频谱分析

摘要

This paper analyzes the characters of seismic wave′s spectrum which above ML 2.8 since October 2009,on records from both ground and underground instruments of stations in the north of Jiangsu province.From which we can find a deviation in the seismic wave′s spec-trums between ground and underground records.The seismic wave′s corner frequency from the ground records are higher than the underground ones about 0.28 Hz,but the peak fre-quency are less than the underground records about 0.22 Hz,and the dominant frequency are also less.In addition,The seismic moment and moment magnitude from the ground records are higher than the underground ones 3.104×10 14 N·m and 0.32.%根据苏北测震台网地面台站和深井台站记录的地震波形资料，分析2009年10月以来台网附近 ML ≥2．8地震波频谱特性。分析可知：地面记录与井下记录的地震波频谱特性存在一定差异，地面记录地震波拐角频率较井下约大0．28 Hz，地震波峰值频率比井下约小0．22 Hz；对于ML ＞4．5地震，地面记录地震波的优势频率范围小于井下记录；地震矩和矩震级地面台站记录数值较大，差值分别为3．104×1014 N·m 和0．32级。