2.5 Dimensional EM Modeling considering Horizontal Magnetic Dipole Source

수평 자기쌍극자 송신원을 이용한 2.5차원 전자탐사 모델링

  • Kwon Hyoung-Seok ;
  • Song Yoonho (Geophysical Exploration and Mining Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Son Jeong-Sul (Geophysical Exploration and Mining Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Suh Jung-Hee
  • 권형석 ((주)희송지오텍) ;
  • 송윤호 (한국지질자원연구원, 탐사개발연구부) ;
  • 손정술 (한국지질자원연구원, 탐사개발연구부) ;
  • 서정희 (서울대학교 지구환경시스템공학부)
  • Published : 2002.05.01

Abstract

In this study, the new modeling scheme has been developed for recently designed and tested electromagnetic survey, which adapts horizontal magnetic dipole with $1\;kHz\~1\;MHz$ frequency range as a source. The 2.5-D secondary field formulation in wavenumber domain was constructed using finite element method and verified through comparing results with layered-earth solutions calculated by integral equations. 2-D conductive- and resistive-block models were constructed for calculating electric field, magnetic field and impedance - the ratio of electric and magnetic fields which are orthogonal each other. This study showed that electric field and impedance are superior in identifying 2-D isolated-body model to magnetic field. In particular, impedance gives more stable results than electric field with similar spatial resolving power, because electric field is divided by magnetic field in impedance. Thus the impedance analysis which uses electric and magnetic fields together would give better result in imaging the shallow anomalies than conventional EM method.