华北地区地震环境噪声特征研究

吴建平1)　欧阳飚2)　王未来1)　姚志祥1)　袁松涌1)

华北地区地震环境噪声特征研究

吴建平1)　欧阳飚2)　王未来1)　姚志祥1)　袁松涌1)

1）中国北京100081中国地震局地球物理研究所2）中国北京100029中国地震局地质研究所

详细信息

中图分类号: P315.63
计量
- 文章访问数: 1588
- HTML全文浏览量: 1401
- PDF下载量: 212
出版历程
- 发布日期: 2012-11-13

Ambient noise level of North China from temporary seismic array

Wu Jianping　Ouyang Biaoup　Wang Weilai　Yao Zhixiang　Yuan Songyong

1） Institute of Geophysics, China Earthquake Administration, Beijing 100081, China2） Institute of Geology, China Earthquake Administration, Beijing 100081, China

摘要

摘要: 利用华北流动地震台阵观测的垂直分向连续波形数据, 通过计算功率谱密度和相应的概率密度函数, 对华北地区地震环境噪声特征进行了分析研究. 结果表明, 东部平原和沉积盆地2 Hz以上的高频环境噪声水平与全球新高噪声模型（NHNM）相近, 周期3——18 s的平均噪声水平低于NHNM和新低噪声模型（NLNM）的平均值; 山区及西部高原的高频噪声水平明显低于NHNM, 周期1——18 s的噪声水平大多明显低于NHNM和NLNM的平均值; 不同区域18 s以上周期的噪声水平差异相对较小. 流动地震台阵部分台站的环境噪声存在明显的昼夜变化, 个别台站噪声水平明显高于周边台站, 表明这些台站受人类活动干扰较大. 不同台站的噪声水平分析表明, 将台站布设在摆坑内, 能在一定程度上降低高频和低频段的噪声水平. 台站环境噪声特征的研究结果可为流动地震台阵观测数据质量的定量评估, 观测期间的台站优化调整等提供重要依据.
- 华北地区　地震台阵　环境噪声　噪声水平　概率密度函数
Abstract: Using vertical component continuous waveform data observed by North China temporary seismic array, we analyzed the seismic ambient noise characteristics inNorth Chinaby calculating the power spectrum density and corresponding probability density function. The results show that high-frequency (above 2 Hz) ambient noise levels in the eastern plain and sedimentary basin region are similar to the global new high noise model (NHNM), the average noise levels at 3mdash;18 s periods are lower than the average values between NHNM and new low noise model (NLNM); high-frequency noise levels in the mountain and western highland region are significantly lower than NHNM, and most of the average noise levels at 1mdash;18 s periods are significantly lower than the average value between NHNM and NLNM; the noise levels with periods over 18 s in different regions show small difference. There is a clear diurnal ambient noise variation in some observations of the temporary seismic array; the noise levels at a few stations are significantly higher than at surrounding stations, implying human activity interference. The noise levels at different stations reveal that high- and low-frequency noise levels can be reduced to some extent by placing the sensor in a vault. The analysis results of station ambient noise characteristics can provide an important basis for quantitative assessment of the seismic array data quality, station optimization and adjustment during observation.

HTML全文

参考文献(1)

Agnew D C, Berger J. 1978. Vertical seismic noise at very low frequencies［J］. J Geophys Res, 83(B11): 5420——5424.

Berger J, Davis P, Ekstrom G. 2004. Ambient Earth noise: A survey of the global seismographic network［J］. J Geophys Res, 109, B11307, doi:10.1029/2004JB003408.

Brune J N, Oliver J. 1959. The seismic noise of the Earth’s surface［J］. Bull Seism Soc Amer, 49(4): 349——353.

Frantii G E, Willis D E, Wilson J T. 1962. The spectrum of seismic noise［J］. Bull Seism Soc Amer, 52(1): 113——121.

McNamara D E, Raymond P B. 2004. Ambient noise levels in the continental United States［J］. Bull Seism Soc Amer, 94(4): 1517——1527.

Murphy A J, Savino J R. 1975. A comprehensive study of long period (20—200 s) Earth noise at the high gain worldwide seismograph stations［J］. Bull Seism Soc Amer, 65(6): 1827——1862.

Peterson J. 1993. Observation and Modeling of Seismic Background Noise［R］. US Geol Surv Tech Rept, 93——322: 1——95.

Stutzman E, Roult G, Astiz L. 2000. Geoscope station noise levels［J］. Bull Seism Soc Amer, 90(3): 690——701.

Webb S C. 1998. Broadband seismology and noise under the ocean［J］. Rev Geophys, 36(1): 105——142.