人工源极低频电磁波场空间分布的计算  

CALCULATION OF SPATIAL DISTRIBUTION OF CSELF ELECTROMAGNETIC FIELD

作　　者：杨静[1,4] 陈小斌[2] 赵国泽 YANG Jing;CHEN Xiao-bin;ZHAO Guo-ze(Linfen Central Seismic Station of Shanxi Earthquake Agency,Linfen 044400,China;National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China;Institute of Geology,China Earthquake Administration,Beijing 100029,China;National Scientific Field Observatory of Continental Rift Dynamics in Taiyuan,Taiyuan 030025,China)

机构地区：[1]山西省地震局,临汾地震监测中心站,临汾044400 [2]应急管理部国家自然灾害防治研究院,北京100029 [3]中国地震局地质研究所,北京100029 [4]太原大陆裂谷动力学国家野外科学观测研究站,太原030025

出　　处：《地震地质》2022年第3期771-785,共15页Seismology and Geology

基　　金：中国地震局地震科技星火计划项目(XH14011YSX);国家发展改革委员会项目(发改高技[2010]1565号);极低频探地工程地震预测分系统(15212z0000001);国家自然科学基金(41074047);山西省地震局创新团队共同资助。

摘　　要：文中对人工源极低频(CSELF)电磁波的空间传播特征进行了较为细致的研究。CSELF电磁波的空间传播区域可划分为近区、远区和波导区。在近区和远区,CSELF电磁波的传播理论与CSAMT相似,文中整理、验证了已有文献中的场强计算公式;在波导区,借鉴无线电通信技术成果,给出了地球-大气层-电离层球形谐振腔模型的CSELF电磁波近似计算公式,并在此基础上设计了可视化软件,实现了3种坐标系下CSELF电磁波场的计算;此外,依据计算结果分析了CSELF在近区、远区、波导区的空间传播特征。研究表明:CSELF电磁场在近区和远区衰减很快,而在波导区衰减较慢;电场比磁场更早进入波导区;在地球模型下,在场源对极点波导区场强存在局部极大值,显示了与水平层状模型完全不同的电磁波传播特征。同时,在基于水平电偶极子源的频率域电磁测深中,远区测深主要依赖于磁场而非电场。文中研究为CSELF的应用提供了理论和计算方面的支持。The electromagnetic(EM)method using controlled-source extremely low-frequency(CSELF)waves is a new technology based on the large-power alternating electromagnetic field generated by an artificial procedure.The biggest advantage of this technology is that it has a long transmitting antenna(tens to hundreds of kilometers)and a large transmitting current(hundreds of amps)and can emit strong and stable electromagnetic waves,covering millions of square kilometers.It can be applied to earthquake monitoring,surveys for mineral resources and treatment of waste nuclear material as well as marine and land communication and detection to ionospheric structure in space.At present,domestic theoretical research on CSELF is not mature enough.This paper has carried out a more detailed study on the spatial propagation characteristics of the electromagnetic(EM)of controlled-source extremely low frequency(CSELF).The large-power CSELF EM waves cover almost all sections of space which can be divided into near,far and waveguide zones according to their propagation characteristics.The propagation of electromagnetic waves in the near and far zone is mainly manifested as the distribution and induction of the conductive currents,and the displacement current and effects of the ionosphere and spheric structure of the Earth can be neglected.The propagation theory of CSELF EM wave is similar to CSAMT in the near and far zones,and it can be described by the theory of quasi-stable field which is analogous to that of the classical theory of EM sounding.In this paper,we collated and verified the field strength calculation formulas in the existing literature.While in the waveguide zone,EM waves appear mainly as the displacement current,and the displacement current and effects of the ionosphere and spheric structure of the Earth must also be considered.The electromagnetic field is mainly the radiation field,and it runs in a way completely different from what the classic theory describes.Using the achievements of communication technology for referenc

关 键 词：CSELF 感应场 辐射场 波场分布 电磁测深 

分 类 号：P315.721[天文地球—地震学]