Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
권호 표지
DOI QR코드

DOI QR Code

Inversion of Time-domain Induced Polarization Data by Inverse Mapping

역 사상법에 의한 시간영역 유도분극 자료의 역산

  • Cho, In-Ky (Division of Geology and Geophysics, Kangwon National University) ;
  • Kim, Yeon-Jung (Department of Geophysics, Kangwon National University)
  • 조인기 (강원대학교 지질, 지구물리학부) ;
  • 김연정 (강원대학교 지구물리학과)
  • Received : 2021.09.27
  • Accepted : 2021.11.22
  • Published : 2021.11.30
Download PDF
⟨ Previous Next ⟩

Abstract

Given that induced polarization (IP) and direct current (DC) resistivity surveys are similar in terms of data acquisition, most DC resistivity systems are equipped with a time-domain IP data acquisition function. In addition, the time-domain IP data include the DC resistivity values. As such, IP and DC resistivity data are intimately linked, and the inversion of IP data is a two-step process based on DC resistivity inversions. Nevertheless, IP surveys are rarely applied, in contrast to DC resistivity surveys, as proper inversion software is unavailable. In this study, through numerical modeling and inversion experiments, we analyze the problems with the conventional inverse mapping technique used to invert time-domain IP data. Furthermore, we propose a modified inverse mapping technique that can effectively suppress inversion artifacts. The performance of the technique is confirmed through inversions applied to synthetic IP data.

유도분극 탐사와 전기비저항 탐사는 자료획득이 유사하며, 대부분의 전기비저항 탐사 시스템에는 시간영역 유도분극 탐사 기능이 함께 탑재되어 있다. 또한 시간영역 유도분극 탐사 자료에는 전기비저항 자료가 내포되어 있다. 따라서 유도분극 탐사와 전기비저항 탐사와는 불가분의 관계가 있으며, 유도분극 자료의 역산도 전기비저항 탐사 자료의 역산에 근거한 2단계 역산법이 적용되고 있다. 그러나 유도분극 탐사는 효과적인 해석법의 부재로 인하여 전기비저항 탐사에 비하여 널리 적용되지 못하고 있다. 이 연구에서는 수치 모델링 및 역산실험을 통하여 시간영역 유도분극 자료의 역산해석에 사용되는 역 사상법의 문제점을 분석하였다. 또한 역 사상법 적용시 문제가 되는 역산잡음을 효과적으로 억제할 수 있는 수정된 역 사상법을 제시하였다. 마지막으로 수치자료에 대한 역산실험을 통하여 개발된 역 사상법의 효과를 검증하였다.

Keywords

References

  1. Cho, I. K., and Kim, Y. J., 2021, Nonlinear inversion of time-domain induced polarization data including negative apparent chargeability data, Geophys. and Geophys. Explor., 24(4), 139-148 (in Korean with English abstract).
  2. Dahlin, T., and Loke, M. H., 2015, Negative apparent chargeability in time-domain induced polarisation data, J. Appl. Geophys., 123, 322-332, https://doi.org/10.1016/j.jappgeo.2015.08.012
  3. Fiandaca, G., Doetsch, J., Vignoli, G., and Auken, E., 2015, Generalized focusing of time-lapse changes with applications to direct current and time-domain induced polarization inversions, J. Appl. Geophys., 203, 1101-1112, https://doi.org/10.1093/gji/ggv350
  4. Fink, J. B., McAlister, E. O., Sternberg, B. K., Wieduwilt, W. G., and Ward, S. H. (Eds.), 1990, Induced Polarization Applications and Case Histories, SEG. https://doi.org/10.1190/1.9781560802594
  5. Gazoty, A., Fiandaca, G., Pedersen, J., Auken, E., and Christiansen, A. V., 2012, Mapping of landfills using time-domain spectral induced polarization data: the Eskelund case study, Near Surf. Geophys., 10, 575-586, http://doi.org/10.3997/1873-0604.2012046
  6. Gasperikova, E., Cuevas, N. H., and Morrison, H. F., 2005, Natural field induced polarization for mapping of deep mineral deposits: a field example from Arizona, Geophysics, 70(6), B61-B66, https://doi.org/10.1190/1.2122410
  7. Jang, H., Park, S., and Kim, H. J., 2014, A simple inversion of induce polarization data collected in the Haenam area of Korea, J. Geophys. Eng., 11, 1-6, https://doi.org/10.1088/1742-2132/11/1/015011
  8. Kim, B., Nam, M. J., and Kim, H. J., 2018, Inversion of time-domain induced polarization data based on time-lapse concept, J. Appl. Geophys., 152, 26-37, doi:10.1016/j.jappgeo.2018.03.010
  9. Oldenburg, D. W., and Li, Y., 1994, Inversion of induced polarization data, Geophysics, 59, 1327-1341, https://doi.org/10.1190/1.1443692
  10. Schlumberger, C., 1920, Etude sur la Prospection Electrique du Sous-sol., Gauthier-Villars, Paris. https://www.worldcat.org/title/etude-sur-la-prospection-electrique-du-sous-sol/oclc/9862310
  11. Seigel, H. O., 1959, Mathematical formulation and type curves for induced polarization, Geophysics, 24, 547-565, https://doi.org/10.1190/1.1438625
  12. Seigel, H., Nabighian, M., Parasnis, D. S., and Vozoff, K., 2007, The early history of the induced polarization method, Lead. Edge, 26(3), 312-321, https://doi.org/10.1190/1.2715054
  13. Slater, L. D., and Sandberg, S. K., 2000, Resistivity and induced polarization monitoring of salt transport under natural hydraulic gradients, Geophysics, 65, 408-420, https://doi.org/10.1190/1.1444735
  14. Sumner, J. S., 1976, Principles of Induced Polarization for Geophysical Exploration, Elsevier, Amsterdam. https://books.google.co.kr/books?hl=ko&lr=&id=nBEXTYVjFswC&oi=fnd&pg=PP1&dq=Sumner,+J.+S.,+1976,+Principles+of+Induced+Polarization+for+Geophysical+Exploration,+Elsevier,+Amsterdam.&ots=0Ebo0idBaV&sig=s9A2xYM2OedmiQh_ZanScQPqgKU#v=onepage&q=Sumner%2C%20J.%20S.%2C%201976%2C%20Principles%20of%20Induced%20Polarization%20for%20Geophysical%20Exploration%2C%20Elsevier%2C%20Amsterdam.&f=false
  15. Vanhala, H., 1997, Mapping oil-contaminated sand and till with the spectral induced polarization (SIP) method, Geophys. Prosp., 45, 303-326, https://doi.org/10.1046/j.1365-2478.1997.00338.x
  16. Ward, S. H., 1990, Resistivity and induced polarization methods, Geotech. and Environ. Geophys, 1, 147-189, https://doi.org/10.1190/1.9781560802785.ch6