1887
  1. Home
  2. A-Z Publications
  3. Geophysical Prospecting
  4. Volume 66, Issue 1
  5. Article
Volume 66 Number 1
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

The electromagnetic response of a horizontal electric dipole transmitter in the presence of a conductive, layered earth is important in a number of geophysical applications, ranging from controlled‐source audio‐frequency magnetotellurics to borehole geophysics to marine electromagnetics. The problem has been thoroughly studied for more than a century, starting from a dipole resting on the surface of a half‐space and subsequently advancing all the way to a transmitter buried within a stack of anisotropic layers. The solution is still relevant today. For example, it is useful for one‐dimensional modelling and interpretation, as well as to provide background fields for two‐ and three‐dimensional modelling methods such as integral equation or primary–secondary field formulations. This tutorial borrows elements from the many texts and papers on the topic and combines them into what we believe is a helpful guide to performing layered earth electromagnetic field calculations. It is not intended to replace any of the existing work on the subject. However, we have found that this combination of elements is particularly effective in teaching electromagnetic theory and providing a basis for algorithmic development. Readers will be able to calculate electric and magnetic fields at any point in or above the earth, produced by a transmitter at any location. As an illustrative example, we calculate the fields of a dipole buried in a multi‐layered anisotropic earth to demonstrate how the theory that developed in this tutorial can be implemented in practice; we then use the example to examine the diffusion of volume charge density within anisotropic media—a rarely visualised process. The algorithm is internally validated by comparing the response of many thin layers with alternating high and low conductivity values to the theoretically equivalent (yet algorithmically simpler) anisotropic solution, as well as externally validated against an independent algorithm.

© 2018 European Association of Geoscientists & Engineers © 2017 European Association of Geoscientists & Engineers
Loading

Article metrics loading...

/content/journals/10.1111/1365-2478.12552
2017-09-07
2024-04-25

  • From This Site

    /content/journals/10.1111/1365-2478.12552
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. BoernerD.E. and WestG.F.1989. A generalized representation of the electromagnetic fields in a layered earth. Geophysical Journal International97, 529–547.
     [Google Scholar]
  2. ChaveA.D. and CoxC.S.1982. Controlled electromagnetic sources for measuring the electrical conductivity beneath the oceans. Journal of Geophysical Research87, 5327–5338.
     [Google Scholar]
  3. ChaveA.D.2009. On the electromagnetic fields produced by marine frequency domain controlled sources. Geophysical Journal International179, 1429–1457.
     [Google Scholar]
  4. ChewW.C.1999. Waves and Fields in Inhomogeneous Media. Wiley‐IEEE Press.
     [Google Scholar]
  5. DeyA. and MorrisonH.F.1973. Electromagnetic coupling in frequency and time‐domain induced‐polarization surveys over a multilayered earth. Geophysics38, 380–405.
     [Google Scholar]
  6. EdwardsR.N.1997. On the resource evaluation of marine gas hydrate deposits using a sea floor transient electric dipole–dipole method. Geophysics62, 63–74.
     [Google Scholar]
  7. EllingsrudS., EidesmoT., JohansenS., SinhaM., MacGregorL. and ConstableS.2002. Remote sensing of hydrocarbon layers by seabed logging SBL: results from a cruise offshore Angola. The Leading Edge21, 972–982.
     [Google Scholar]
  8. GoldsteinM.A. and StrangwayD.W.1975. Audio‐frequency magnetotellurics with a grounded electric dipole source. Geophysics40, 669–683.
     [Google Scholar]
  9. HunzikerJ., ThorbeckeJ. and SlobE.2015. The electromagnetic response in a layered vertical transverse isotropic medium: a new look at an old problem. Geophysics80, F1–F18.
     [Google Scholar]
  10. KaufmanA.A. and KellerG.V.1983. Frequency and Transient Soundings. Elsevier.
     [Google Scholar]
  11. KeyK.2009. 1D inversion of multicomponent, multifrequency marine CSEM data: methodology and synthetic studies for resolving thin resistive layers. Geophysics74, F9–F20.
     [Google Scholar]
  12. KongJ.A.1972. Electromagnetic fields due to dipole antennas over stratified anisotropic media. Geophysics37, 985–996.
     [Google Scholar]
  13. LahiriB.N. and PriceA.T.1939. Electromagnetic induction in non‐uniform conductors, and the determination of the conductivity of the earth from terrestrial magnetic variations. Philosophical Transactions of the Royal Society of London Series A, Mathematical and Physical Sciences237, 509–540.
     [Google Scholar]
  14. LøsethL.O. and UrsinB.2007. Electromagnetic fields in planarly layered anisotropic media. Geophysical Journal International170, 44–80.
     [Google Scholar]
  15. MailletR.1947. The fundamental equations of electrical prospecting. Geophysics4, 529–556.
     [Google Scholar]
  16. SchollC. and EdwardsR.N.2007. Marine downhole to seafloor dipole‐dipole electromagnetic methods and the resolution of resistive targets. Geophysics72, WA39–WA49.
     [Google Scholar]
  17. SchmuckerU. and WeideltP.1975. Aarhus lecture notes.
  18. StrackK.M.1984. The deep transient electromagnetic sounding technique: first field‐test in Australia. Exploration Geophysics15, 251–259.
     [Google Scholar]
  19. StreichR. and BeckenM.2011. Sensitivity of controlled‐source electromagnetic fields in planarly layered media. Geophysical Journal International187, 705–728.
     [Google Scholar]
  20. SwidinskyA., HölzS. and JegenM.2012. On mapping seafloor mineral deposits with central loop transient electromagnetics. Geophysics77, E171–E184.
     [Google Scholar]
  21. UrsinB.1983. Review of elastic and electromagnetic wave propagation in horizontally layered media. Geophysics48, 1063–1081.
     [Google Scholar]
  22. WaitJ.R.1982. Geo‐Electromagnetism. Academic Press.
     [Google Scholar]
  23. WardS.H.1967. Electromagnetic theory for geophysical applications. In: Mining Geophysics, Vol. II, Theory (ed S.H.Ward ), pp. 13–196. Society of Exploration Geophysicists.
     [Google Scholar]
  24. WardS.H. and HohmannG.W.1988. Electromagnetic theory for geophysical applications. In: Electromagnetic Methods in Applied Geophysics, Vol. 1, Theory: Investigations in Geophysics3 (ed M.N.Nabighian ), pp. 131–311. Society of Exploration Geophysicists.
     [Google Scholar]
  25. WeideltP.2007. Guided waves in marine CSEM. Geophysical Journal International171, 153–176.
     [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/1365-2478.12552
Loading
The electromagnetic response of a horizontal electric dipole buried in a multi‐layered earth
Geophysical Prospecting 66, 240 (2018); https://doi.org/10.1111/1365-2478.12552
/content/journals/10.1111/1365-2478.12552
/content/journals/10.1111/1365-2478.12552
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): Electromagnetics; Modelling; Theory

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