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pure and applied geophysics

, Volume 120, Issue 1, pp 136–150 | Cite as

Electromagnetic response of a buried cylindrical conductor for sheet and line current sources

  • S. O. Ogunade
Article

Abstract

A major problem in electromagnetic induction studies in regions of localized source fields, such as the auroral and equatorial electrojet regions, is the source effect. Using an analytical model, the electromagnetic response of a buried conducting cylinder to sheet current and line current excitations has been studied for the period rangeT=5 s to 24 h. The validity of the numerical results obtained from the analytical model are compared with the numerical results obtained from a finite difference model. The results show that for periods less than 30 min, there is no significant difference in the response of the cylinder to both source fields. However, significant differences are observed at longer periods. It was also observed that the equivalent height at which a uniform sheet current at 100 km above the earth's surface can be approximated by a line current varies as a function of the source period.

Key words

Geophysical prospecting Localized source fields Equivalent height 

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References

  1. Gagniard, L. (1953),Basic Theory of the Magneto-telluric Method of Geophysical Prospecting, Geophysics18, 605–633.Google Scholar
  2. D'Yakonov, B. P. (1959),The Diffraction of Electromagnetic Waves by a Cylinder in a Homogeneous Half-space, Izv. Acad. Sci USSR Geophys. Ser.9, 950–955.Google Scholar
  3. Hermance, J. F., andPeltier, W. R. (1970),Magneto-telluric Fields of a Line Current, J. Geophys. Res.71, 3351–3356.Google Scholar
  4. Mareschal, M. (1976),On the Problem of Simulating the Earth's Induction Effects in Modeling Polar Magnetic Substorms, Rev. Geophys. Space Phys.14, 403–409.Google Scholar
  5. McNish, A. G. (1938),Heights of Electric Currents Near the Auroral Zone, Terr. Magn. atmos. Elect.43, 67–75.Google Scholar
  6. Ogbuehi, P. O., andOnwumechili, A. (1963),Recent Measurements of the Magnetic Field of the Equatorial Electrojet in Nigeria, J. Geophys. Res.68, 2421–2424.Google Scholar
  7. Ogunade, S. O., andDosso, H. W. (1980/81),The Response of a Horizontal Conducting Cylinder Embedded in a Uniform Earth for Uniform and Line Current Sources, Pure appl. Geophys.119, 51–58.Google Scholar
  8. Ramaswamy, V., Jones, F. W., Dosso, H. W., andNienaber, W. (1980),A Comparison of Numerical, Analogue Model, and Field Station Vertical Magnetic-fields for the Vancouver Island Region, Phys. Earth Planet. Inter.22, 60–67.Google Scholar
  9. Schmucker, U.,Neue Rechenmethoden zur Tiefensondierung, inProtokoll uber das Kolloquium Erdamagnetische Tiefensondierung in Rothenberge/Westf. (ed. P. Weidelt (Institut fur Geophysik, Gottingen 1971), pp. 1–39.Google Scholar
  10. Schmucker, U.,Direkte und iterative Verfahren zur Behandlung 2-dimensionaler Leitfahigkeitsmodelle, inProtokoll Kolloquium Erdmagnetische Tiefensondierung Grafrath (ed. A. Berktold) (Institut fur Geophysik, Uni. Munchen 1974), pp. 429–441.Google Scholar

Copyright information

© Birkhäuser Verlag 1982

Authors and Affiliations

  • S. O. Ogunade
    • 1
  1. 1.Department of PhysicsUniversity of IfeIle-IfeNigeria

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