地震台站背景噪声是影响地震观测质量的主要因素之一，分析背景噪声随频率的分布对于地震观测具有重要意义。通过宁夏陶乐、灵武井下地震观测站地表背景噪声记录，对比分析二者原始地动波形差异及其频谱特征，计算观测站背景噪声功率谱密度PSD值及三分向1—20 Hz各倍频程带宽平均噪声RMS值，分析井下与地表背景噪声PSD值、RMS值差异及变化特征。结果表明，同一观测站，井下地震计平均噪声RMS值比地表小10倍左右；对比分析陶乐、灵武井下地震观测站地表平均噪声RMS值，二者相差不大，但对比井下平均噪声RMS值发现，灵武井下地震观测站平均噪声RMS值较大。
The background noise of seismic stations is one of the main factors affecting the quality of seismic observations. Analyzing the distribution of background noise with frequency is of great significance for seismic observation. Based on the ground surface background noise records of the Ningxia Taole and Lingwu underground seismic observation stations, this study compares and analyzes the differences and spectral characteristics of the original ground motion waveforms of the two stations, calculates the PSD values of the background noise of the observation station and the RMS values of average noisefor each octave band of 1-20 Hz forthe three-component observations, and analyzes the difference and variation characteristics of the PSD value and RMS value of the background noise between the undergroundand the surface observations. The results show that at the same observation station, the average noise RMS values of the downhole seismometer is about 10 times smaller than that of the surface. Comparing and analyzing the average noise RMS values of Taole and Lingwu underground seismic observation stations show that the difference between the two is not significant. However, comparing the RMS values of the average downhole noise, it is found that the RMS values of the average noise of the Lingwu underground seismic observation station are relatively larger.
2022,43（5）: 86-93 收稿日期：2021-07-05
DOI：10.3969/j.issn.1003-3246.2022.05.011
基金项目：宁夏自然科学基金（项目编号：2022AAC03689）；宁夏地震科研基金（项目编号：NX202002）
作者简介：唐浩(1990-),男,宁夏海原人,硕士研究生,主要从事地震分析、监测运维工作。E-mail:757986177@qq.com
参考文献：
侯颉,余大新,叶庆东,等.北京测震台网台基背景噪声特征[J].华北地震科学,2019,37(3):56-61.
李少睿,毛国良,王党席,等.井下地震计方位角检测技术应用研究[J].地球物理学报,2016,59(1):299-310.
刘巧霞.基于地震台阵技术的地脉动背景噪声研究[D].合肥:中国科学技术大学,2018.
刘瑞丰,郑秀芬,杨辉,等.地震观测数据的管理与服务[M].北京:地震出版社,2015.
裴晓,尹继尧,杨庭春.张江台地表与深井地震观测对比分析[J].地震工程学报,2013,35(2):366-371.
唐浩,李鸿庭,白晓川,等.陶乐地震台地表与井下地震计记录波形对比研究[J].大地测量与地球动力学,2022,42(7):760-765.
王芳,王伟涛,龙剑锋,等.中国大陆地区宽频带地震台网台基噪声特征[J].地震学报,2019,41(5):569-584.
王凯明.基于密集台阵的背景噪声聚束分析成像及其在青藏高原东北缘的应用[D].北京:中国地震局地球物理研究所,2019.
徐纪人,赵志新.深井地球物理观测的最新进展与中国大陆科学钻探长期观测[J].地球物理学进展,2009,24(4):1 176-1 182.
