宁夏区域地震观测背景噪声特征  

Characteristics of Seismic Observation Background Noise in Ningxia Region

作　　者：唐浩 徐金银 何秋菊[1] 马瑞 李青梅[1] TANG Hao;XU Jinyin;HE Qiuju;MA Rui;LI Qingmei(Earthquake Agency of Ningxia Hui Autonomous Region,Yinchuan 750001,China)

机构地区：[1]宁夏回族自治区地震局,银川市750001

出　　处：《大地测量与地球动力学》2024年第11期1199-1206,共8页Journal of Geodesy and Geodynamics

基　　金：宁夏自然科学基金(2022AAC03689);中国地震局“三结合”课题(3JH-202301065)。

摘　　要：选取宁夏台网2022-01-01~12-31期间14个测震台站和2023-01-01~03-31期间23个新建基准站记录的三分向连续波形资料,计算台站噪声加速度功率谱密度及相应的概率密度函数分布,对不同频段、不同区域台站的噪声水平特征进行分析。结果表明,在大于1Hz频段,地震计采用山洞安装方式的台站噪声水平昼夜变化均值比其他台站低2dB左右。在大于3Hz频段,台站噪声水平存在明显的昼夜变化,与人类活动规律相吻合;宁夏南部和盐池区域台站的噪声水平昼夜变化均值分别为6dB和4dB,宁夏北部和中部区域台站的噪声水平昼夜变化均值为7dB。宁夏南部区域台站在各频段的噪声水平均值都低于其他地区。在0.1~0.3Hz、0.3~1Hz、1~10Hz和10~35Hz频段,宁夏南部区域台站的噪声水平均值比北部区域分别低3dB、5dB、8dB和3dB;在0.1~0.3Hz、0.3~1Hz和1~3Hz频段,宁夏中部区域台站的噪声水平均值比北部区域分别低3dB、4dB和3dB;在3~10Hz和10~35Hz频段,宁夏北部区域台站的噪声水平比中部区域分别低2dB和4dB;在0.1~0.3Hz和0.3~35Hz频段,盐池区域台站的噪声水平均值与北部和中部区域相近。To calculate the station noise acceleration power spectral density and the corresponding probability density function distribution,we select the three-direction continuous waveform data recorded by 14 seismic stations in Ningxia seismic network from January 1,2022 to December 31,2022 and 23 newly built reference stations from January 1,2023 to March 31,2023.Then,we analyze the characteristics of noise levels in different regions and different frequency bands.The results show that in the frequency band greater than 1 Hz,the stations with cave installation method have a mean circadian variation of noise level that is about 2 dB lower than that of other stations.In the frequency band greater than 3 Hz,there are obvious circadian variations in noise level,which is consistent with the law of human activities.The mean diurnal variation of noise levels in southern Ningxia and Yanchi region are 6 dB and 4 dB.The average circadian variation of noise level in northern and central Ningxia is 7 dB.The mean noise level in southern Ningxia is lower than that in other regions.In the frequency bands of 0.1-0.3 Hz,0.3-1 Hz,1-10 Hz and 10-35 Hz,the average noise levels in southern Ningxia are 3 dB,5 dB,8 dB and 3 dB lower than that in northern region.In the frequency bands of 0.1-0.3 Hz,0.3-1 Hz and 1-3 Hz,the mean noise levels in central Ningxia are 3 dB,4 dB and 3 dB lower than that in northern region.In the 3-10 Hz and 10-35 Hz frequency bands,the average noise levels in northern Ningxia are 2 dB and 4 dB lower than that in central Ningxia.In the frequency bands of 0.1-0.3 Hz and 0.3-35 Hz,the mean noise levels in Yanchi region are similar to that in northern and central regions.

关 键 词：宁夏区域 背景噪声 噪声水平 昼夜变化 频段 

分 类 号：P315[天文地球—地震学]