Investigation of the line arrangement of 2D resistivity surveys for 3D inversion*
Keisuke Inoue 1 5 Hiroomi Nakazato 1 Mutsuo Takeuchi 2 Yoshihiro Sugimoto 3 Hee Joon Kim 4 Hiroshi Yoshisako 1 Michiaki Konno 1 Daisuke Shoda 11 Institute for Rural Engineering, National Agriculture and Food Research Organisation, 2-1-6, Kannondai, Tsukuba-shi, Ibaraki 305-8609, Japan.
2 Geo Vest, Inc., 3-530-175, Karasuyama, Tsuchiura-shi, Ibaraki 300-0836, Japan.
3 DIA Consultants Co., Ltd, 2-272-3 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 330-8638, Japan.
4 Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 608-737, Korea.
5 Corresponding author. Email: ksk@affrc.go.jp
Exploration Geophysics 49(2) 231-241 https://doi.org/10.1071/EG17019
Submitted: 1 February 2017 Accepted: 5 February 2017 Published: 17 March 2017
Abstract
We have conducted numerical and field experiments to investigate the applicability of electrode configurations and line layouts commonly used for two-dimensional (2D) resistivity surveys to 3D inversion. We examined three kinds of electrode configurations and two types of line arrangements, for 16 resistivity models of a conductive body in a homogeneous half-space. The results of the numerical experiment revealed that the parallel-line arrangement was effective in identifying the approximate location of the conductive body. The orthogonal-line arrangement was optimal for identifying a target body near the line intersection. As a result, we propose that parallel lines are useful to highlight areas of particular interest where further detailed work with an intersecting line could be carried out. In the field experiment, 2D resistivity data were measured on a loam layer with a backfilled pit. The reconstructed resistivity image derived from parallel-line data showed a low-resistivity portion near the backfilled pit. When an orthogonal line was added to the parallel lines, the newly estimated location of the backfilled pit coincided well with the actual location. In a further field application, we collected several 2D resistivity datasets in the Nojima Fault area in Awaji Island. The 3D inversion of these datasets provided a resistivity distribution corresponding to the geological structure. In particular, the Nojima Fault was imaged as the western boundary of a low-resistivity belt, from only two orthogonal lines.
Key words: 2D resistivity survey data, 3D inversion, orthogonal line, parallel line.
References
Akaike, H., 1978, A Bayesian analysis of the minimum AIC procedure: Annals of the Institute of Statistical Mathematics, 30, 9–14Awata, Y., and Mizuno, K., 1998, The strip map of the surface fault ruptures features associated with the 1995 Hyogo-ken Nanbu Earthquake, central Japan (1 : 10,000): Geological Survey of Japan, 12, 74 [in Japanese].
Gharibi, M., and Bentley, L. R., 2005, Resolution of 3-D electrical resistivity images from inversions of 2-D orthogonal lines: Journal of Environmental & Engineering Geophysics, 10, 339–349
| Resolution of 3-D electrical resistivity images from inversions of 2-D orthogonal lines:Crossref | GoogleScholarGoogle Scholar |
Holcombe, H. T., and Jiracek, G. R., 1984, Three-dimensional terrain corrections in resistivity surveys: Geophysics, 49, 439–452
| Three-dimensional terrain corrections in resistivity surveys:Crossref | GoogleScholarGoogle Scholar |
Imamura, S., and Fukuoka, K., 2004, An approach of 3D terrain correction for 2D resistivity survey data: Proceedings of the 110th SEGJ Conference, 67–69 [in Japanese].
Inoue, K., Nakazato, H., Kubota, T., Takeuchi, M., Sugimot, Y., Kim, H. J., and Furue, K., 2016, Three-dimensional inversion of in-line resistivity data for monitoring a groundwater recharge experiment in a pyroclastic plateau: Exploration Geophysics, ,
| Three-dimensional inversion of in-line resistivity data for monitoring a groundwater recharge experiment in a pyroclastic plateau:Crossref | GoogleScholarGoogle Scholar |
Jackson, P. D., Earl, S. J., and Reece, G. J., 2001, 3D resistivity inversion using 2D measurements of the electric field: Geophysical Prospecting, 49, 26–39
| 3D resistivity inversion using 2D measurements of the electric field:Crossref | GoogleScholarGoogle Scholar |
Nakazato, H., Inoue, K., Nakanishi, N., Ito, Y., Okazaki, K., and Wang, Z., 2004, 3-D terrain corrections in 2-D resistivity survey: Proceedings of the 111th SEGJ Conference, 169–172 [in Japanese].
Nakazato, H., Inoue, K., Nakanishi, N., Takeuchi, M., Sugimoto, Y., and Kim, H. J., 2005, 3-dimensional resistivity survey around the Nojima fault in Awaji Island: Proceedings of the 113th SEGJ Conference, 85–88 [in Japanese].
Nakazato, H., Inoue, K., Nakanishi, N., and Wang, Z., 2006, New 3-D terrain correction method for 2-D resistivity survey: Technical report of the National Institute for Rural Engineering, Issue 204, 281–286 [in Japanese with English abstract].
Sasaki, Y., 1994, 3-D resistivity inversion using the finite-element method: Geophysics, 59, 1839–1848
| 3-D resistivity inversion using the finite-element method:Crossref | GoogleScholarGoogle Scholar |
Sasaki, Y., Hasegawa, N., and Matsuoka, T., 2005, Toward practical 3D resistivity surveys: Effects of 3D topography and structures on interpretation: Proceedings of the 112th SEGJ Conference, 207–210 [in Japanese].
Sugimoto, Y., 1988, A Bayesian approach to geotomographic inversion: Proceedings of the 79th SEGJ Conference, 28–33 [in Japanese].
Sugimoto, Y., and Inoue, M., 1998, Study on 3-D resistivity tomography in civil engineering: Butsuri Tansa, 51, 676–687
Sugimoto, Y., Nakazato, H., Takeuchi, M., Kim, H. J., Inoue, K., Yamada, N., and Aono, T., 2004, Practical 3-D electrical resistivity survey method using measurements from a few 2 D survey lines: Proceedings of the 111th SEGJ Conference, 165–168 [in Japanese].
Suzuki, K., Oda, Y., Tani, K., Mogi, T., Hayashi, H., and Jyomori, A, 1996, 3D electrical survey and step continuous wave radar survey for Nojima Fault Area – results of measurement of resistivity at trenching site: Butsuri Tansa, 49, 511–521