Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
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3D Electrical Resistivity Tomography via Horizontal Electric Field Component

3차원 전기비저항탐사 향상을 위한 수평 전기장 성분 측정법 제안

  • Churl Hyun Jo (Subsurface Information Technologies, Inc.) ;
  • In-Ki Cho (Department of Geophysics, Kangwon National University)
  • 조철현 (지하정보기술(주) 기술연구소) ;
  • 조인기 (강원대학교 지구물리학과)
  • Received : 2025.06.29
  • Accepted : 2025.08.20
  • Published : 2025.08.31
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Abstract

Electrical resistivity surveys are one of the most widely used high-resolution near-surface geophysical techniques. However, conventional data acquisition methods based on collinear arrays typically measure and interpret only the electric field components aligned with the survey line. Therefore, the horizontal variations in other directions are neglected. Such a limitation is inherent in two-dimensional electrical resistivity tomography (2D ERT); however, it is a critical constraint in three-dimensional electrical resistivity tomography (3D ERT). Hence, this study proposes a method for the vectorial measurement of the horizontal components of electric field changes at potential electrode stations. This approach enables the determination of both the magnitude and direction of surface electric field variation. The resulting data are expected to improve the resolution and reliability of 3D ERT inversion.

전기비저항탐사는 광물탐사, 토목 및 환경분야 조사 등 천부지구물리탐사 기법중 가장 널리 활용되는 방법으로 주로 공선형배열(collinear array)을 채택하여 수행된다. 이러한 전통적인 현장 자료취득은 전기장의 측선방향성분만을 측정하고 해석하고 있다. 이러한 한계는 2차원 전기비저항탐사(2D ERT)에서는 불가피하지만, 3차원 전기비저항탐사(3D ERT)에서는 중요한 제약으로 작용할 수 있다. 본 연구에서는 전위전극 지점에서 전기장 수평성분을 벡터측정하고 해석하는 방법을 제안한다. 이를 통해 지표전기장 변화의 크기뿐 아니라 방향도 함께 파악할 수 있다. 이와 같은 새로운 측정방식은 3D ERT 역산결과를 향상시킬 것으로 기대한다.

Keywords

Acknowledgement

이 연구는 2차원전기비저항탐사에서 음의 전위차가 측정되는 경우에 대하여 많은 토론과 논쟁을 수행한 한국지구물리학자들에 의해 영감을 받았다. 특히 KIGAM의 고 김정호, 정현기, 이명종 박사, 그리고, 서울대학교 민동주 교수 등의 선행 연구에 감사드린다.

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