昌平地震台钻孔应变观测数据质量分析

Quality analysis of borehole strain observation data at Changping Seismic Station

昌平地震台钻孔应变测项多年来积累了大量观测数据。采用调和分析及相对标定等方法,从观测数据连续率、稳定性等方面评估观测数据质量,并分析不同钻孔应变仪器的映震能力。结果表明:该台钻孔应变在运行测项稳定、可靠,在一定时间内观测资料质量整体较好。选取震中距300 km范围内历史典型震例进行分析,发现该台站体应变在华北地区多次5级以上地震前具有明显趋势异常,分量应变仪多次记录到临震异常。分析认为,昌平地震台钻孔应变观测资料能够反映其所在区域的构造活动和应变状态,可以为地震监测与研究提供可靠的基础数据。

A large amount of observation data has been accumulated over the years in the borehole strain measurement program of the Changping Seismic Station.The quality of the observed data was assessed in terms of continuity and stability by reconciliation analysis and relative calibration,and the earthquake-reflecting capability of different borehole strain instruments was analyzed.The results show that the operational measurements are stable and reliable,and the overall quality of the observation data is good within a certain time.The analysis of typical historical earthquakes within 300 km from the station shows that the strain of the station has obvious trend anomalies before many earthquakes of magnitude 5 or above in North China,and the component strain instrument has recorded critical anomalies many times.The analyses show that the borehole strain observation data of the Changping Seismic Station can reflect the tectonic activity and strain state of the region where it is located,and can provide reliable basic data for earthquake monitoring and research.