小北湖火山台迁建前后观测数据对比分析

Comparative analysis of observations before and after the Xiaobeihu Seismic Station relocation

小北湖火山台原址位于原始森林保护区,按照林区防火要求,2019年选址迁建。选取迁建前后小北湖火山台观测数据,通过计算不同频段范围内背景噪声记录的加速度功率谱密度,分析了迁建前后地震观测台站的噪声特征。结果表明,在1—20 Hz频段内,迁建后功率谱噪声值普遍降低10—20 dB;从RMS值来看,UD向降低22.0%,EW向降低58.2%,NS向降低62.8%,达到Ⅰ级台基水平,迁建后井下环境抗干扰能力更强,观测效果更好。

The Xiaobeihu Volcanic Seismic Station was originally located in the original forest protection area.According to the forest fire protection requirements,the station was relocated in 2019.Based on the observation data of the Xiaobeihu Volcanic seismic station before and after the relocation,the noise characteristics of the seismic station before and after the relocation are analyzed by calculating the power spectral density of acceleration observations in different frequency bands.The results show that the power spectrum noise decreases by 10-20 dB in the frequency band of 1-20 Hz.The RMS of the UD,EW,and NS components decreased by 22.0%,58.2%,and 62.8%,respectively,reaching the standard of level I seismic station.After the relocation,the underground environment has a stronger anti-interference ability and better observation effect.