新疆乌鲁木齐及周边地区非天然地震特征与识别  

CHARACTERISTICS AND IDENTIFICATION OF NON-NATURAL EARTHQUAKES IN URUMQI AND SURROUNDING AREAS OF XINJIANG

作　　者：曹昌军 陈向军[1] 金花[1] 李奎 CAO Chang-jun;CHEN Xiang-jun;JIN Hua;LI Kui(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2024年第1期70-80,共11页Inland Earthquake

基　　金：新疆地震科学基金课题(202203)资助.

摘　　要：选取2017—2023年M L2.4~3.8新疆地震台网记录的20个爆破、5个塌陷、25个地震事件,采用波形记录特征、垂直向P波初动方向、振幅比、时频分析方法开展非天然地震特征研究。分析结果表明,非天然地震和天然地震在时域和频域方面存在明显不同,爆破事件垂直向P波向上发育、周期小、S波的振幅和周期变化不明显、容易与面波混淆;塌陷事件垂直向P波向下、P波S波成组出现且接近、波形较爆破简单;两者震动衰减较快,面波发育。爆破Pc/Sm的值大于0.42、地震小于0.42、塌陷Pc/Sm的值大于0.62。爆破Pm/Sm的值大于0.70、地震小于0.70、集中在0.40左右、塌陷Pm/Sm的值在0.55左右;时频分析方面爆破和塌陷频率成分简单,能量峰值在4 Hz以下,频域较窄,以低频面波为主,衰减较快,呈现出“少峰”特征。地震频率成分复杂,分布在4~16 Hz之间,频域较宽,主频不固定,呈现“多峰”特征,能量分布在S波。以上识别判据为今后区分研究区内非天然地震特征提供有效参考。Twenty blasting events,five collapse events and 25 seismic events recorded by M L2.4~3.8 Xinjiang Seismic Network from 2017 to 2023 were selected.The waveform recording characteristics,vertical P-wave initial direction,amplitude ratio and time-frequency analysis method were used to study the characteristics of non-natural earthquakes.The analysis results show that there are obvious differences between non-natural earthquakes and natural earthquakes in time domain and frequency domain.The vertical P-wave of blasting events develops upward,the period is small,the amplitude and period of S-wave do not change significantly,and it is easy to be confused with surface waves.The collapse event is vertically downward P wave,P wave S wave appears in groups and is close to each other,and the waveform is simpler than blasting.The vibration attenuation of both is fast,and the surface wave is developed.The value of blasting Pc/Sm is greater than 0.42,the earthquake is less than 0.42,and the value of collapse Pc/Sm is greater than 0.62.The value of Pm/Sm of blasting is greater than 0.70,the earthquake is less than 0.70,concentrated at about 0.40,and the value of Pm/Sm of collapse is about 0.55.In terms of time-frequency analysis,the frequency components of earthquakes and collapses are simple,the energy peak is below 4 Hz,the frequency domain is narrow,mainly low-frequency surface waves,and the attenuation is fast,showing the characteristics of“few peaks”.The seismic frequency components are complex,distributed between 4 Hz and 16 Hz,the frequency domain is wide,the main frequency is not fixed,showing“multi-peak”characteristics,and the energy is distributed in the S wave.The above identification criteria provide an effective reference for distinguishing the characteristics of non-natural earthquakes in the study area in the future.

关 键 词：非天然地震 爆破 塌陷 波形特征 振幅比 

分 类 号：P315.7[天文地球—地震学]