Joint Inversion of DC Resistivity and Travel Time Tomography Data: Preliminary Results

전기비저항 주시 토모그래피 탐사자료 복합역산 기초 연구

  • 김정호 (한국지질자원연구원 지반안전연구부) ;
  • 이명종 (한국지질자원연구원 지반안전연구부) ;
  • 조창수 (한국지질자원연구원 지진연구센터) ;
  • 서정희 (서울대학교 지구환경시스템공학부)
  • Published : 2007.11.30

Abstract

Recently, multi-dimensional joint inversion of geophysical data based on fundamentally different physical properties is being actively studied. Joint inversion can provide a way to obtaining much more accurate image of the subsurface structure. Through the joint inversion, furthermore, it is possible to directly estimate non-geophysical material properties from geophysical measurements. In this study, we developed a new algorithm for jointly inverting dc resistivity and seismic traveltime data based on the multiple constraints: (1) structural similarity based on cross-gradient, (2) correlation between two different material properties, and (3) a priori information on the material property distribution. Through the numerical experiments of surface dc resistivity and seismic refraction surveys, the performance of the proposed algorithm was demonstrated and the effects of different regularizations were analyzed. In particular, we showed that the hidden layer problem in the seismic refraction method due to an inter-bedded low velocity layer can be solved by the joint inversion when appropriate constraints are applied.

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