1887
Volume 48 Number 5
  • E-ISSN: 1365-2478

Abstract

Abstract

We define the apparent frequency effect in induced polarization (IP) as the relative difference between apparent resistivities measured using DC excitation on the one hand and high‐frequency excitation (when the IP effect vanishes) on the other. Assuming a given threshold for the minimum detectable anomaly in the apparent frequency effect, the depth of detection of a target by IP can be defined as that depth below which the target response is lower than the threshold for a given electrode array. Physical modelling shows that for the various arrays, the depth of detection of a highly conducting and volume polarizable target agrees closely with the depth of detection of an infinitely conducting and non‐polarized body of the same shape and size. The greatest depth of detection is obtained with a two‐electrode array, followed by a three‐electrode array, while the smallest depth of detection is obtained with a Wenner array when the array spread is in‐line (i.e. perpendicular to the strike direction). The depth of detection with a Wenner array improves considerably and is almost equal to that of a two‐electrode array when the array spread is broadside (i.e. along the strike direction).

Loading

Article metrics loading...

/content/journals/10.1046/j.1365-2478.2000.00212.x
2001-12-24
2020-06-05
Loading full text...

Full text loading...

References

  1. ApparaoA.1997.Developments in Geoelectrical Methods.Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi, India.
    [Google Scholar]
  2. ApparaoA., Gangadhara RaoT., Sivarama SastryR., Subrahmanya SarmaV.1992. Depth of detection of buried conductive targets with different electrode arrays in resistivity prospecting. Geophysical Prospecting40, 749760.
    [Google Scholar]
  3. ApparaoA., SarmaV.S., SastryR.S., SrinivasG.S.1993a.Master resistivity profiles over buried conducting targets with different electrode arrays.National Geophysical Research Institute, Hyderabad, India.
    [Google Scholar]
  4. ApparaoA., SastryR.S., SarmaV.S.1995. Laboratory experiments with the IP method on massive and disseminated cement‐graphite bodies. Proceedings of the Golden Jubilee Seminar of Geological Survey of India on Exploration Geophysics, 1945–1995, Calcutta, in press.
    [Google Scholar]
  5. ApparaoA., Sivarama SastryR., Subrahmanya SarmaV.1994. Spectral studies on buried surface and volume polarizable target models. Exploration Geophysics25, 3137.
    [Google Scholar]
  6. ApparaoA., Sivarama SastryR., Subrahmanya SarmaV.1997. Depth of detection of buried resistive targets with some electrode arrays in resistivity prospecting. Geophysical Prospecting45, 365375.
    [Google Scholar]
  7. ApparaoA., Subrahmanya SarmaV., Sivarama SastryR., SrinivasG.S.1993b.A catalogue of modified pseudodepth sections with different electrode arrays over buried conductive targets.NGRI Publication, Hyderabad, India.
    [Google Scholar]
  8. BarkerR.D.1989. Depth of investigation of collinear symmetrical four‐electrode arrays. Geophysics54, 10311037.
    [Google Scholar]
  9. BhattacharyaB.B. & DuttaI.1982. Depth of investigation studies for gradient arrays over homogeneous and isotropic half‐space. Geophysics47, 11981203.
    [Google Scholar]
  10. EskolaL., ElorantaE., PuranenR.1984. A method of calculating IP anomalies for models with surface polarization. Geophysical Prospecting32, 7987.
    [Google Scholar]
  11. EvjenH.M.1938. Depth factors and resolving power of electrical measurements. Geophysics3, 7895.
    [Google Scholar]
  12. GuptasarmaD.1983. Effect of surface polarization on resistivity modeling. Geophysics48, 98106.
    [Google Scholar]
  13. OldenburgD.W. & LiY.1999. Estimating depth of investigation in dc resistivity and IP surveys. Geophysics64, 403416.
    [Google Scholar]
  14. ParasnisD.S.1966.Mining Geophysics. Methods in Geochemistry and Geophysics Series 3. Elsevier Science Publishing Co.
    [Google Scholar]
  15. RoyA. & ApparaoA.1971. Depth of investigation in direct current methods. Geophysics36, 943959.
    [Google Scholar]
  16. SeigelH.O.1949. Theoretical and experimental investigation into the application of the phenomenon of overvoltage to geophysical prospecting. PhD thesis, University of Toronto. In: Over Voltage Research and Geophysical Applications ( ed. J.R.Wait ). Pergamon Press, London, 1959.
  17. Van NostrandR.G.1953. Limitations on resistivity methods as inferred from the buried sphere problem. Geophysics18, 423433.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1046/j.1365-2478.2000.00212.x
Loading
/content/journals/10.1046/j.1365-2478.2000.00212.x
Loading

Data & Media loading...

  • Article Type: Research Article
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