1887
  1. Home
  2. A-Z Publications
  3. Geophysical Prospecting
  4. Volume 25, Issue 1
  5. Article
Volume 25 Number 1
  • E-ISSN: 1365-2478

Abstract

A

The transient response of a layered structure to plane wave excitation can be considered to be composed of a series of waves and a ground wave. For the case of a half‐space of conductivity and permeability the maximum in the electric field is found at a depth and time when =2/2.

This formula can be used to estimate the depth to a buried horizontal conductor with an accuracy that depends upon the resistive contrast at the conductor's surface.

The above ray type of solution can be converted to a solution composed of a number of modes by the use of a Poisson transform and the transformed solutions yield decay constants that are consistent with the previously reported results.

In the case of a finite source, the maximum in the electric field is strongly directed. The direction depends upon the geometry of the source and the air‐earth interface. Although the maximum varies with direction it can be shown that in some directions similar laws to that above are valid.

The depth to a conductor can be estimated from the early part of the transients when the ground wave is removed. The removal of the ground wave from the transient is facilitated by the use of an apparent conductivity formula.

Although these results were obtained under restrictive conditions they do provide some insight into the electrical transients that are encountered by studying more complex models.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.1977.tb01153.x
2006-04-27
2024-04-19

  • From This Site

    /content/journals/10.1111/j.1365-2478.1977.tb01153.x
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Abramowitz, M., and Stegun, I. A., 1965, Handbook of mathematical functions with graphs, and mathematical tables, New York , Dover publications, pp. 1046.
    [Google Scholar]
  2. Buselli, G., 1974, Multi channel transient electromagnetic measurements near cloncurry, Bull. Aust. Soc. Exploration Geophysics5, 31–47.
    [Google Scholar]
  3. Campbell, G., and Foster, R. M., 1948, Fourier Integrals for practical applications, Van Nostrand Co., New York , pp. 177.
    [Google Scholar]
  4. Clay, C. S., Greischar, L. L., and Kan, T. K., 1974, Matched filter detection of electromagnetic transient reflections, Geophysics39, 683–691.
    [Google Scholar]
  5. Courant, R., and Hilbert, D., 1965, Methods of mathematical physics Vol. 1, Interscience Publishers Inc., New York , pp. 561.
    [Google Scholar]
  6. Goldstein, S., 1932, Some two dimensional diffusion problems with circular symmetry, Proc. London. Math. Soc. (2), 34, 51–88.
    [Google Scholar]
  7. Gray, A., and Mathews, G. B., 1966, A treatise on Bessel functions and their applications to physics, Second edition prepared by Gray, A. , and Macrabert, T.M. , Dover, New York .
    [Google Scholar]
  8. Kunetz, G., 1972, Processing and interpretation of magnetotelluric soundings, Geophysics37, 1005–1021.
    [Google Scholar]
  9. Lee, T., and Lewis, R., 1974, Transient EM response of a large loop on a layered ground, Geophysical Prospecting22, 430–444.
    [Google Scholar]
  10. Lee, T., 1975, Transient electromagnetic response of a sphere in a layered medium, Geophysical Prospecting23, 492–512.
    [Google Scholar]
  11. Morrison, H. F., Phillips, R. J., and O'Brien, D. P., 1969, Quantitative Interpretation of transient electromagnetic fields over a layered half space, Geophysical Prospecting17, 82–101.
    [Google Scholar]
  12. Velekin, A. B., and Bulgakov, Ju. I., 1967, Transient method of electrical prospecting (one loop version). Presented to the UNO international seminar on Geophysical methods of prospecting for ore minerals. Ministry of Geology of the U.S.S.R., Moscow.
  13. Velekin, A. B., Bulgakov, Ju. I., Gigoryeu, G. O., and Polikorpov, A. M., 1971, Equipment for the method of transient processes, the MPPO‐1 Apparatus. Paper No. 9 in a collection of papers on the Transient process method in the search for sulphide ore bodies, “Nedra” Leningrad, pp. 243.
  14. Ward, S. H., Ryu, J., Glenn, W. E., Hohmann, G. W., Smith, B. D., and Dey, A., 1974, Electromagnetic methods in conductive terrains, Geoexploration, 12, 121–184.
    [Google Scholar]
  15. Wait, J. R., 1960, Propagation of electromagnetic pulses in a homogeneous conducting earth App. Sc. Res. B8, 213–253.
    [Google Scholar]
  16. Wait, J. R., 1971, Transient excitation of the earth by a line source of current, Proc. IEEE (Letters)59, 1287–1288.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.1977.tb01153.x
Loading
  • Article Type: Research Article

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