沙尘暴对测震台站环境噪声干扰的特征分析——以二连浩特台为例

通过计算二连浩特测震台站地表和井下连续观测数据的加速度PSD值和相应的PDF值，研究沙尘暴对测震台站环境噪声水平的干扰特征及井下观测对减小沙尘暴影响的效果。结果表明，沙尘暴对测震台站环境噪声水平有较大干扰，主要体现在4 Hz、9 Hz附近及10~20 Hz和低于10 s频段。其中，沙尘主要影响10~20 Hz频段背景噪声；大风主要影响4 Hz、9 Hz附近背景噪声；低于10 s频段的三分向背景噪声受干扰特征与风向有一定的相关性；10 s~4 Hz频段沙尘暴对环境噪声水平没有影响。井下观测能较好地压制沙尘暴对测震台站环境噪声水平的干扰。

Characterization of Environmental Noise Interference of Sandstorms on Seismic Stations——Using Erenhot Station as an Example

By calculating the acceleration PSD values and the corresponding PDF values of the continuous surface and borehole observations at Erenhot seismic station, the interference characteristics of sandstorms on the environmental noise level of the seismic station and the effect of downhole observations on suppressing sandstorms are studied. The results show that the sandstorms interfere with the ambient noise level of the seismic stations, mainly in the frequency bands of 4 Hz, 9 Hz, 10-20 Hz and below 10 s. The sand and dust mainly affect the background noise in the frequency band of 10-20 Hz, the high wind mainly affects the background noise near 4 Hz and 9 Hz, and the three-divisional background noise below 10 s has a certain correlation with the wind direction. 10 s-4 Hz band sandstorms have no effect on the environmental noise level. The borehole observation can better suppress the interference of sandstorms on the ambient noise level of the seismic stations.