pure and applied geophysics

, Volume 125, Issue 2–3, pp 341–367 | Cite as

Substitute conductors for electromagnetic response estimates

  • Ulrich Schmucker


Various concepts exist to define substitute conductors for empirical response estimates at singular frequencies: Chapman's shell-core model, the Cagniard-Tikhonov apparent resistivity, the Niblett-Bostick and Molochnov transformation, thep*z* transformation. They are all interrelated and assign comparable resistivities to the substitute conductor at a given frequency. Applications to synthetic response data of plane and spherical conductors show under which conditions these substitutions come closest to the model and which influence of source dimensions and Earth's sphericity can be expected.p*z* transformed global response data forS andDst variations demonstrate how substitute conductors may serve as useful guides in inverse procedures.

Key words

Electromagnetic induction magnetotelluric and geomagnetic sounding electric conductivity of crust and mantle 


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Copyright information

© Birkhäuser Verlag 1987

Authors and Affiliations

  • Ulrich Schmucker
    • 1
  1. 1.Institute für GeophysikGöttingenFederal Republic of Germany

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