지구물리와물리탐사 (Geophysics and Geophysical Exploration)

  • 제23권4호
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  • Pages.223-229
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  • 2020
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  • 1229-1064(pISSN)
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  • 2384-051X(eISSN)
한국지구물리·물리탐사학회 (Korean Society of Earth and Exploration Geophysicists)
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소형 루프 전자탐사에서 기하학적 수직탐사와 주파수 수직탐사

Geometric and Frequency Soundings in Small-Loop Electromagnetic Surveys

  • 조인기 (강원대학교 지질, 지구물리학부) ;
  • 안경찬 (강원대학교 지질, 지구물리학부)
  • Cho, In-Ky (Division of Geology and Geophysics, Kangwon National University) ;
  • Ahn, Kyoung-Chan (Division of Geology and Geophysics, Kangwon National University)
  • 투고 : 2020.06.03
  • 심사 : 2020.11.09
  • 발행 : 2020.11.30
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초록

소형 루프 전자탐사법은 효과적인 물리탐사법으로 다양한 목적으로 천부 조사에 널리 사용되고 있다. 소형 루프 전자탐사에서는 기하학적 수직탐사와 주파수 수직탐사가 적용되고 있으나, 주파수 수직탐사의 경우 그 유효성 대하여 논란이 지속되고 있다. 이 연구에서는 소형 루프 전자탐사에 대한 1차원 모델링을 통하여 기하학적 수직탐사와 주파수 수직탐사의 유효성을 검증하고자 하였다. 수치 실험 결과 기하학적 수직탐사는 효과적으로 지하의 심도에 따른 지하의 정보 해석이 가능한 것으로 나타났다. 반면 주파수 수직탐사는 송수신 간격이 비교적 클 경우, 즉 유도상수가 크다는 조건을 만족해야만 유효한 해석이 가능하며, 그렇지 못할 경우 하부 지층의 정보해석이 불가능한 것으로 나타났다.

Small-loop EM techniques have been used in many geophysical investigations, including shallow engineering and environmental surveys. Even though geometric and frequency soundings have been widely used, there is a debate regarding the effectiveness of frequency sounding, especially when the coil spacing is small. In this study, we analyzed the effectiveness of geometric as well as frequency soundings via the one-dimensional modeling of small-loop EM surveys. The numerical results reveal that geometric sounding can effectively provide underground information. Conversely, the frequency soundings are only effective when the loop spacing is relatively large, that is, when the induction number is large. On the contrary, the frequency soundings fail to provide any information concerning the subsurface layers if the loop spacing is not large.

키워드

참고문헌

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