摘要
利用Welch算法,选取天津数字地震台网31个台站记录资料中不同时段的无震记录,对无震观测资料进行功率谱计算,然后进行统计分析,得出了天津地区的背景噪声特征：就季节而言,背景噪声值的高值出现在夏天和秋天,低值出现在春天和冬天;就时间而言,高值出现在白天的14时,低值出现在夜间的2时。对比噪声功率谱曲线发现,在0.125~1 Hz频段内有一个明显的峰值,这主要是受海洋的影响。在1-20 Hz频段内,天津地区的背景噪声值高值区出现在中心城区、静海、滨海新区,低值区出现在蓟县、宝坻、宁河、武清,且中心城区、静海、滨海新区白天时段的背景噪声值明显高于夜间时段,这主要是受人为噪声的影响,而在0.125-1 Hz频段内,天津所有地区差异不大。
Using WELCH model, this paper calculated power spectrum without earthquake for 31 stations and got characteristics of background noise in Tianjing： the noise was high in summer and autumn while low in spring and winter; the peak value appeared in 14：00 and the low value appeared in 02：00. By making comparison of noise power spectrum curves, with frequency of 0. 125 1 Hz the peak value was influenced by ocean while with frequency of 1 - 20 Hz the peak area appeared in city center like Jinghai, Binghai while the low value area appeared in Baodi. The peak value period appeared in day time more than evening because of human activity. With frequency of 0. 125 - 1 Hz, difference of background noise level in each region of Tianjin was very small.
出处
《内陆地震》
2015年第2期170-175,共6页
Inland Earthquake
基金
天津市地震局课题(20141016)资助
关键词
数字地震台
背景噪声
功率谱密度
天津
Digital seismic station
Background noise
Power spectrum density
Tianjin
