1887
Volume 35, Issue 4
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Electrical resistivity imaging surveys widely used in many environmental and engineering studies have also been conducted in water-covered areas. Surveys in water-covered areas include conventional surveys using multi-electrode resistivity systems where part of the survey line crosses a river or stream, and surveys conducted entirely within a water-covered environment. Surveys that are located entirely within a water-covered environment utilise electrodes mounted on a streamer, towed behind a boat. The streamer can be dragged along the water bottom, or float on the water surface. In this paper, the smoothness-constrained least-squares inversion method commonly used to interpret electrical resistivity imaging data from land surveys is adapted for underwater surveys. To accommodate the water bottom topography, a distorted finite-element grid is used to calculate the apparent resistivity values for the inversion model. The first few rows of elements are used to model the water layer, while the lower part of the grid is used for the sub-bottom resistivity distribution. For robust inversion, the water column resistivity and geometry must be known accurately as a large proportion of the current flows through the water layer. The section of the Earth below the bottom surface is subdivided into a large number of rectangular cells. The water column resistivity and geometry in the earth model is fixed, and the inversion program attempts to determine the resistivity of the cells that would most accurately reproduce the observed resistivity measurements. Implementation of water column resistivity and geometric constraints is demonstrated using numerical simulations and field data. Examples of electrical resistivity imaging surveys conducted on and across water bodies including rivers and near-shore marine environments are shown.

© 2004 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG04266
2004-12-01
2026-01-19

  • From This Site

    /content/journals/10.1071/EG04266
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Acworth, R.I., and Dasey, G.R., 2003, Mapping of the hyporheic zone around a tidal creek using a combination of borehole logging, borehole electrical tomography and cross-creek electrical imaging: Hydrogeology Journal,11, 368-377.
  2. Auken, E., and Christiansen, A.V., 2004, Layered and laterally constrained 2D inversion of resistivity data: Geophysics,69, 752-761.
  3. Belaval, M., Lane, J.W., Jr., Lesmes, D,R, and Kineke, G.C., 2003, Continuous-resistivity profiling for coastal groundwater investigations–three case studies: Proceedings of the Symposium of the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2003, San Antonio, Texas, 14 p.
  4. Bernstone, C, and Dahlin, T., 1999, Assessment of two automated electrical resistivity data acquisition systems for landfill location surveys: two case histories: Journal of Environmental and Engineering Geophysics,4, 113-122.
  5. Christiansen, A.V., and Auken, E., 2004, Optimizing a layered and laterally constrained 2D inversion of resistivity data using Broyden's update and ID derivatives: Journal of Applied Geophysics, 56, 247-262.
  6. Dahlin, T., 1996, 2D resistivity surveying for environmental and engineering applications: First Break,14, 275-284.
  7. deGroot-Hedlin, C, and Constable, S., 1990, Occam's inversion to generate smooth, two-dimensional models form magneto telluric data: Geophysics,55, 1613-1624.
  8. Edwards L.S., 1977, A modified pseudosection for resistivity and induced-polarization: Geophysics,42, 1020-1036.
  9. Ellis, R.G., and Oldenburg, D.W., 1994, Applied geophysical inversion: Geophysical Journal International,116, 5-11.
  10. Griffiths, D.H., and Barker, R.D., 1993, Two-dimensional resistivity imaging and modelling in areas of complex geology: Journal of Applied Geophysics,29. 211-226.
  11. Li, Y. and Oldenburg, D.W., 2000, 3-D inversion of induced polarization data: Geophysics, 65, 1931-1945.
  12. Loke, M.H., 2000, Topographic modelling in resistivity imaging inversion: 62nd EAGE Conference & Technical Exhibition Extended Abstracts, D-2
  13. Loke, M.H., and Barker, R.D., 1996a, Rapid least-squares inversion of apparent resistivity pseudosections using a quasi-Newton method: Geophysical Prospecting,44, 131-152.
  14. Loke, M.H., and Barker, R.D, 1996b, Practical techniques for 3D resistivity surveys and data inversion: Geophysical Prospecting,44, 499-523.
  15. Loke, M.H., Acworth, I., and Dahlin, T, 2003, A comparison of smooth and blocky inversion methods in 2D electrical imaging surveys: Exploration Geophysics,34, 182-187.
  16. Madsen, J.A., Brown, L., McKenna, T., Snyder, S., Krantz, D., Manheim, E, Haeni. E-R, White, E., and Ullman, W., 2001, Geophysical characterization of fresh and saline water distribution in a coastal estuarine setting: Proceedings of the Symposium of the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), March 4-7, Denver Colorado.
  17. Manheim, F.T., Krantz, D.E., Snyder, D.S., Bratton, J.E, White, E.A., and Madsen, J.A., 2001, Streaming resistivity surveys and core drilling define groundwater discharge into coastal bays of the Delmarva Peninsula: Geological Society of America Annual Meeting, November 1-10, 2001,33(6), A42.
  18. Panissod, C, Dabas, M., Hesse, A., Jolivet, A., Tabbagh, J., and Tabbagh, A., 1998, Recent developments in shallow depth electrical and electrostatic prospecting using mobile arrays: Geophysics,65, 1542-1550.
  19. Press, W.H., Teukolsky, S.A., Vetterling, W.T., and Flannery, B.P., 1992, Numerical recipes in C (2nd edition): Cambridge University Press, Cambridge.
  20. Ritz, M-, Parisot, J.-C, Diouf, S., Beauvais, A., and Dione, E, 1999, Electrical imaging of lateritic weathering mantles over granitic and metamorphic basement of eastern Senegal, West Africa: Journal of Applied Geophysics,41, 335-344.
  21. Seaton, W.J., and Burbey, T.J., 2000, Aquifer characterization in the Blue Ridge Physiographic Province using resistivity profiling and borehole geophysics: Journal of Environmental and Engineering Geophysics,5(3), 45-58.
  22. Silvester P.P., and Ferrari, R.L., 1990, Finite elements for electrical engineers (2nd edition): Cambridge University Press.
  23. Smith, T-, Hoversten, M., Gasperikova, E., and Morrison, E, 1999, Sharp boundary inversion of 2D magnetotelluric data: Geophysical Prospecting,47, 469-86.
  24. Sorenson, K., 1996, Pulled Array Continuous Profiling: First Break,14, 85-90.
  25. White, R.M.S., Collins, S., Denne, R., Hee, R., and Brown, P., 2001, A new survey design for 3D IP modelling at Copper Hill: Exploration Geophysics,32, 152-155.
  26. Wynn, J.C., and Grosz, A.E., 2000, Induced-polarization - a tool for mapping titanium-bearing placers, hidden metallic objects, urban waste on and beneath the seafloor: Journal of Environmental and Engineering Geophysics,5(3), 27-35.
/content/journals/10.1071/EG04266
Loading
  • Article Type: Research Article
Keyword(s): imaging; inversion; Resistivity; surveys; underwater; water-covered

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error