Permafrost properties, patterns and processes in the Transantarctic Mountains region

The properties, distribution patterns and thermal processes that influence the active layer and permafrost in the Transantarctic Mountains region of Antarctica, as deduced from our soil investigations since 1964 and drilling investigations since 1990, are outlined. The active layer depth varies from around 80 cm thick in coastal areas to <5 cm in inland and upland regions, due to the effect of the adiabatic lapse rate. Saline, ice-bonded, dry permafrost and transitional types of permafrost all occur. Ice content is highest in ice-bonded permafrost of the coastal regions and lowest in inland dry permafrost where values may be <1%. At the regional scale, ice-bonded permafrost most commonly occurs at lower elevations and beneath younger land surfaces but with increasing elevation, distance inland and land surface age, dry permafrost becomes predominant. At the local scale (<1 m) there are large variations in the depth to the permafrost table due to variations in ground surface features. Permafrost properties are largely governed by solar energy receipt, but albedo, air temperature cooling and available soil moisture strongly modulate the conversion of solar energy receipt into soil heating. These factors account for the considerable broad-scale and local variability in permafrost properties that exists. Copyright © 2006 John Wiley & Sons, Ltd.