Attenuation Calculations for a Two-Layer Earth-Crust Waveguide for Sub-Surface Electromagnetic Propagation.

摘要

New calculations for the mode characteristics for an idealized model of the earth crust waveguide have been carried out. Specifically,the authors have considered a homogeneous waveguide region bounded below by a homogeneous transition layer whose conductivity is intermediate between that of the main waveguide region and the bottom conductive region. A numerical supplement (if not included here) is available from the authors. It is shown that the presence of the transition layer usually increases the attenuation rate of the dominant modes although there are some interesting exceptions. (Author)