宜昌地震台山洞伸缩仪干扰分析

Interference analysis of the cave extensometer at Yichang seismic station

宜昌地震台新型SS-Y伸缩仪安装至今运行已有10年,本文采用Venedikov调和函数方法对宜昌地震台山洞观测SS-Y伸缩仪2014—2022年数据资料进行分析。结果表明:伸缩仪数据内在质量较好,两个分量潮汐因子远大于1;且NS分量观测精度优于EW分量。通过地球物理台网数据跟踪分析平台发现,宜昌台2014—2022年间SS-Y伸缩仪数据预处理前有各类干扰存在。经综合分析,归纳为4大类干扰因素(观测系统、自然、场地、人为)影响,数据曲线形态表现多具有突跳、台阶、断记、错误数据、同步趋势等基本特征。在对2021年2月21日发生的场地环境干扰进行数据滤波处理后,两个分量可清晰记录到尖脉冲爆破干扰。对这些干扰特征的归类甄别,可为台站形变伸缩仪数据日后预处理准确识别及异常判定提供参考。

The new SS-Y extensometer has been in operation for 10 years at Yichang seismic station.Data obtained by the extensometer over the period of 2014 to 2022 at Yichang seismic station were analyzed using the Venedikov harmonic analysis method.The results showed that the internal quality of the data was good.The values of the tide factor of M2 wave of the two components were much greater than 1.The observation accuracy of the NS component is higher than that of the EW component.According to the geophysical network observation data tracking and analysis platform,it was found that there were various types of interference of SS-Y extensometer over the period of 2014 to 2022.After comprehensive analysis,it can be summarized into the influence of four categories of interference factors(observation system,natural environment,site environment and human interference),and the curve was mostly characterized by sudden jumps,steps,breaks,error data,synchronous trend changes and so on.Such as,after filtering processing of the site environmental interference occurred on February 21,2021,the two components can be clearly recorded to the sharp pulse explosion interference.The classification and screening of these interference characteristics can provide a reference for the accurate identification and abnormal determination of the station data in the future.