Antarctica, with an area of 14 million km2, is the worlds largest continent, yet exposed ground on which permafrost soils occur covers a mere 49,000 km2, or about 0.35% of the entire continent (Fox and Cooper 1994). The continent is roughly circular in outline, and its topography is dominated by two massive ice sheets (Fig. 2.1); the East Antarctic Ice Sheet with an average elevation of around 3,000 m, and the West Antarctic Ice Sheet with an average elevation of around 1,500 m. A major physiographic feature is the Transantarctic Mountains, which extend over 3,500 km and separate the two ice sheets. Bare ground areas are found scattered around the margin of the continent where the ice sheets have thinned or receded, in the Antarctic Peninsula and along the Transantarctic Mountains (Fig. 2.1). The largest ice-free area is in the Transantarctic Mountains (23,000 km2 estimate), which includes approximately 7,000 km2 in the Dry Valley region, the largest contiguous area of bare ground.
The climate for formation of soils and permafrost throughout Antarctica is severe. With very low mean annual temperatures, negligible effective precipitation and rare occurrences of mosses and lichens, except for the Antarctic Peninsula where plant life including some grasses are more abundant, the soils have aptly been described as Cold Desert Soils (Tedrow and Ugolini 1966; Campbell and Claridge 1969). The exposed landscapes are dominated by glacial valleys with land surfaces and deposits that show the influence of glacial activity, which has extended from the Late Pleistocene to earlier than Miocene times (Denton et al. 1993; Marchant et al. 1993). Notwithstanding the tiny proportion of the continent that is ice-free and exposed to weathering processes, a large degree of diversity is found in both the soils and permafrost, owing to the wide variations in the environmental and geomorphic forces.
Iain B. Campbell
Land & Soil Consultancy Services, 23 View Mount, Nelson, 7011, New Zealand [email protected]
R. Margesin (ed.) Permafrost Soils, Soil Biology 16,
DOI: 10.1007/978-3-540-69371-0, © Springer-Verlag Berlin Heidelberg 2009
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