VLF Ground‐Based Measurements in Antarctica: Their Relationship to Stratifications in the Subsurface Terrain

Abstract

The phase and amplitude characteristics of the near‐field broadside to a long horizontal dipole operated close to ground level at very low frequencies can be used to obtain useful information about the nature of the subsurface media. This study is about antarctic glacial terrain and makes use of data collected recently in the Byrd glacier area to draw tentative conclusions about the nature of the glacial ice and underlying earth. Data obtained by use of this method suggest that the depth of the ice layer is in the neighborhood of 2250 meters, that the bulk relative complex dielectric constant of the ice may be approximated by the value 6.0‐ j 14 at 12.8 kHz, and that the conductivity of the underlying earth approaches 0.10 mho meter −1 . A reflection coefficient of approximately 0.60 is indicated when plane waves arrive at vertical incidence at the surface of the ice. These figures are shown to be reasonable when compared with available data from other sources.