铁岭SS-Y伸缩仪加速拉张的短期变化

铁岭地震台SS-Y型伸缩仪2018年6月起出现NS分量的持续拉张和EW分量的小幅压性变化,经初步分析,发现仪器工作状态良好,并排除各类干扰因素。采用三点线性平滑滤波,对NS、EW分量进行趋势项、周期项提取处理,发现自2018年6月起,NS分量趋势性拉张且年变增加,EW分量趋势性压缩且年变减小,与以往相比,趋势和年变周期变化特征差异性较大,结合同一山洞的水管倾斜仪和垂直摆倾斜仪同时段产生同步转折变化及历史震例,分析认为,铁岭SS-Y型洞体应变NS分量变化为震前异常的可能性较大,后续应跟踪分析该异常的趋势性走向变化。

Short-term variation analysis of Tieling SS-Y telescopic acceleration

According to the analysis of the continuous tension of the NS component and the small amplitude change of the EW component of the SS-Y telescopic instrument of Tieling Seismic Station after June 2018, preliminary analysis of the instrument in good working condition and no one is disturbing and the surrounding environment exists, then, the three-point linear smoothing filter is used to analyze the trend items and periodic items of the two component data of NS and EW. It is found that from June 2018, NS trended tensile and annual change, the EW component trend compression year becomes smaller, the trend characteristics of two directions and annual variation period change characteristics are larger than the previous ones, combined with the same cave water pipe tilt meter synchronous transition changes occur at the same time as the vertical pendulum tilting instrument. The historical case analysis shows that the NS component of the Tieling SS-Y type cavity is more likely to be a precursor anomaly, and the trending trend of the anomaly is followed by follow-up analysis.