乌鲁木齐及周边地区新冠疫情前后背景噪声分析  

Background Noise Analysis Before and After the COVID-19 Epidemic in Urumqi and Its Surrounding Areas

作　　者：邓明文 许鑫 李金[3] DENG Mingwen;XU Xin;LI Jin(Kuerle Earthquake Monitoring Center Station,Kuerle 841000,China;China University of Geosciences,Wuhan 430074,China;Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,China)

机构地区：[1]库尔勒地震监测中心站,新疆库尔勒841000 [2]中国地质大学,武汉430074 [3]新疆维吾尔自治区地震局,乌鲁木齐830011

出　　处：《华南地震》2023年第3期7-18,共12页South China Journal of Seismology

基　　金：新疆维吾尔自治区重点研发计划(2022B03001-1、2020B03006-3);新疆维吾尔自治区自然科学基金(2020D01A83);中国地震局地震科技星火计划项目(XH22025D、XH21042);中国地震局“监测、预报、科研”三结合课题(3JH-202001098、3JH-202301003)联合资助。

摘　　要：选取2019年1月至2022年12月乌鲁木齐及周边地区14个测震台站垂直分量波形记录,通过计算PSD(功率谱密度)和PDF(概率密度函数),统计不同频段功率谱密度分布情况,对比乌鲁木齐及周边地区疫情前后背景噪声变化特征,并结合大数据探讨人口迁徙与背景噪声变化的相关性。同时计算了疫情前后研究区最小完备震级(Mc),对比分析其地震监测能力变化特征。结果表明:研究区地震背景噪声水平受疫情影响出现不同程度的下降,高频段(1~35 Hz)最大下降幅度为36.6 dB,部分台站长周期频段下降突出,这是人类活动间接影响的;上述变化与人口迁徙大数据变化呈现了极大的正相关。此外在疫情封闭期间,地震监测能力并没有明显的提高,但部分台站获得更为清晰的震相记录。The vertical component waveform records of 14 seismic stations in Urumqi and surrounding areas from January 2019 to December 2022 were selected,and the distribution of power spectral density in different frequency bands was calculated by calculating PSD(power spectral density)and PDF(probability density function).The characteristics of background noise changes before and after the epidemic in Urumqi and its surrounding areas were compared,and the correlation between population migration and background noise changes was discussed in combination with big data.The minimum complete magnitude(Mc)of the study area before and after the epidemic was also calculated,and the change characteristics of its seismic monitoring capacity were compared and analyzed.The results show that the seismic background noise level in the study area has decreased in different degree due to the influence of the epidemic,with a maximum decrease of 36.6 dB in the high frequency band(1-35 Hz),and the long-period frequency band of some stations has decreased significantly,which was indirectly influenced by human activities.In addition,there was no significant improvement in seismic monitoring capacity during the epidemic closure period,but some stations obtained clearer seismic phases records.

关 键 词：新冠疫情 地震背景噪声 概率密度函数 人口迁徙大数据 地震监测能力 

分 类 号：P315.78[天文地球—地震学]