浙江省测震观测台网井下地震计方位角检测与校正

Detection and correction of azimuth of borehole seismograph in Zhejiang Seismic Network

选取浙江省测震台网景宁、北仑、南麂岛地震台井下地震计观测数据,采用地震数据波形相关性分析法,与地表地震计同步观测数据进行相关性分析,检测并校正井下地震计方位角,结果发现,3个地震台井下地震计方位角实际偏差分别为82.2°、-22.8°、32.2°。分析认为,井下地震计安装易受线缆应力影响,导致方位角与实际偏差过大,应在应力释放完成后固定地震计,并架设地表地震计进行数据相关性分析,以确定方位角可靠性。

The borehole seismograph observation data are chosen form Jingning,Beilun and Nanji Island in Zhejiang Seismic Network,the correlation analysis of the borehole seismic waveform data with the ground seismometer observation data is performed synchronously to detect and correct the borehole seismograph azimuth angle.The results are found that actual deviation of three seismic borehole seismograph azimuth were 82.2°,22.8°and 32.2°respectively.It is concluded that the installation of borehole seismograph is easily affected by cable stress,which leads to too large deviation between azimuth and its reality.So it is necessary to fix the seismometer after the completion of stress release,and set up a ground seismometer for data correlation analysis so as to determine the reliability of azimuth angle.