电磁监测台站观测的舒曼谐振背景变化  

Schumann resonances variation observed from Electromagnetic monitoring stations

作　　者：范晔[1,2] 汤吉[1] 赵国泽[1] 王立凤[1] 吴江星[3] 李细顺[4] 黄天保[5] 刘广宽[6] 

机构地区：[1]地震动力学国家重点实验室(中国地震局地质研究所),北京100029 [2]中国地震台网中心,北京100045 [3]吉林省地震局长春合隆台,吉林市130000 [4]河北省地震局红山基准台,河北红山055350 [5]海南省地震局琼中基准地震台,海南琼中572900 [6]江苏省地震局南京基准地震台,南京210014

出　　处：《地球物理学报》2013年第7期2369-2377,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40974041;41074047);中央公益性科研院所基本科研业务专项(DF-IGCEA-0608-2-15);地震行业科研专项(200808010)资助

摘　　要：舒曼谐振是由闪电激发的电离层与地面之间的全球电磁震荡,在地球与电离层空腔中传播,由于共振作用,其电磁波能量明显高于其他频率电磁波能量.舒曼谐振具有稳定的频域参数和频谱结构,近几年的研究发现,地震发生前会使这些固有参数发生扰动,因此利用舒曼谐振异常来进行地震短临监测可能是一种行之有效的手段.要判断舒曼谐振地震电磁异常,了解舒曼谐振电磁场背景变化规律是前提.本文利用极低频电磁台站观测的天然电磁场数据,处理和分析了各台站观测的舒曼谐振频率电磁场功率谱随时间的变化,得到了舒曼谐振随季节和纬度的背景变化规律.并提出将舒曼谐振背景变化规律应用到地震短临监测预报中,能够为今后辨别地震监测中的舒曼谐振异常提供物理依据.Schumann resonances（SR） are a set of frequencies of electromagnetic（EM） waves in the natural cavity formed by the earth′s surface and its ionosphere,in the extremely low frequency（ELF） range,caused by natural electrical activity of the earth and its atmospheric environment.Because of the resonance interaction,EM energy of SR is stronger than the other frequencies′.In recent years,studies have found that earthquakes would disturb the stable parameters and spectra of SR,so using SR anomaly to implement earthquake monitoring is effective.However,finding out the EM field background variation is the basis of distinguishing the seismic EM anomaly.In this paper,utilizing ELF electromagnetic monitoring stations′ natural electromagnetic field data,we processed and analyzed electromagnetic field components′ power spectrum curve of SR frequencies,and obtained Schumann resonance background change with season and latitude.Comparing SR′ electromagnetic field curves of one station,we can see electromagnetic field intensity changes with seasons obviously.This is weaker in winter and stronger in summer,and the amplitude of sinusoidal variation differs by two orders of magnitude.Comparing the same frequency′s graphs of different stations,it is observed that electromagnetic field intensity is enhancing with the decreasing of the latitude.The background variation study will provide physical basis for distinguishing the earthquake electromagnetic animaly.

关 键 词：舒曼谐振 电磁场强度 季节变化 纬度变化 数据处理 

分 类 号：P319[天文地球—固体地球物理学]