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Research Paper

Underground EM 1D Modeling and Inversion

지중 전자탐사 1차원 모델링 및 역산

In-ky Cho1*
,
Kyoung-chan Ahn2
조 인기1*
,
안 경찬2
1Professor, Division of Geology & Geophysics, Kangwon National University, Chuncheon, Korea
2Master’s course student, Department of Geophysics, Kangwon National University, Chuncheon, Korea
1강원대학교 지질·지구물리학부 교수
2강원대학교 지구물리학과 석사과정
*Corresponding Author
31 October 2021. pp. 464-474
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Abstract

Electromagnetic (EM) methods have been widely used to detect conductive anomalous bodies. Research and field surveys have focused mainly on surface or airborne EM survey, but few research and field applications for underground EM surveys have been conducted. An underground EM survey, in which the transmitter and receiver are located in a narrow underground space, relies on a one-dimensional (1D) survey because, unlike with a surface EM survey, performing conventional two- or three-dimensional survey is difficult. Accordingly, to interpret underground EM data accurately, proper 1D modeling and inversion that consider the induced-currents generated in both the upper and lower layers of the transmitter are necessary. In this study, 1D underground EM modeling and inversion programs were developed. Then, through 1D inversion experiments on the synthetic data, it was confirmed that frequency and time-domain underground EM surveys could effectively recover underground resistivity stratification.

Keywords
Underground EM
1D Modeling
1D Inversion

전자탐사는 전도성 이상체 탐지에 효과적인 물리탐사법으로 자원탐사, 지반조사 등 다양한 분야에 널리 사용되어 왔다. 전자탐사는 지표 및 항공탐사 위주로 연구 및 현장조사가 수행되었으나, 터널이나 지하 공간 조사 등에 필요한 지중 전자탐사는 연구 및 적용 사례가 많지 않다. 지하에 송수신기가 위치하는 지중 전자탐사는 공간적 제약으로 통상적인 2차원 혹은 3차원 탐사가 어렵기 때문에 1차원 탐사에 의존해야 한다는 제약이 있다. 또한 지중 전자탐사 자료의 정확한 해석을 위해서는 송신기 상부 및 하부 지층에서 발생하는 유도전류를 모두 고려하는 모델링 및 역산법이 필요하다. 이 연구에서는 지중 전자탐사 자료의 해석을 위한 1차원 모델링 및 역산 프로그램을 개발하였다. 또한 수치자료에 대한 역산실험을 통하여 주파수 영역 및 시간 영역 지중 전자탐사는 지하의 전기비저항 층서 구조에 대한 정량적 해석이 가능함을 확인하였다.

키워드
지중 전자탐사
1차원 모델링
1차원 역산
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Information
  • Publisher :The Korean Society of Mineral and Energy Resources Engineers
  • Publisher(Ko) :한국자원공학회
  • Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
  • Journal Title(Ko) :한국자원공학회지
  • Volume : 58
  • No :5
  • Pages :464-474
  • Received Date : 2021-09-02
  • Revised Date : 2021-10-13
  • Accepted Date : 2021-10-26
  • DOI :https://doi.org/10.32390/ksmer.2021.58.5.464
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