Permafrost-Hydrogeologic Regimen in Two Ice-Free Valleys, Antarctica, from Electrical Depth Sounding

Abstract

Electrical resistivity field measurements and subsequent laboratory analyses of the electrical properties of soils and rocks, both frozen and unfrozen, are used to describe the type and configuration of permafrost in Wright and Taylor Valleys, Antarctica. Rock and soil samples saturated with potable water have resistivities that increase four orders of magnitude when cooled from +21°C to −25°C. Resistivities greater than 10,000 ohm-m are associated with an impermeable variety of permafrost referred to in this paper as confining permafrost. Confining permafrost is continuous throughout the ice-free valleys except near McMurdo Sound and under saline lakes. A hydrologic connection between lakes and the groundwater reservoir beneath the lakes is inferred; thus, part of the brines contained in the lakes may be derived from groundwater.