Geoscience Reference
In-Depth Information
Chapter 9
Cryosols of Antarctica
9.1
Introduction
Only 0.35 % of Antarctica is ice-free, amounting to an area of 49,500 km
2
(Fig.
9.1
).
The ice-free areas are distributed from greatest to least: the Transantarctic and
Pensacola Mountains (53 %), the Antarctic Peninsula (20 %), MacRobertson Land
(11 %), and Queen Maud Land (7 %), with the remaining areas comprising 9 %
(Table
9.1
).
Antarctica is divided by the Transantarctic Mountains into what is commonly
known as East Antarctica, which contains the massive East Antarctic ice sheet
(EAIS) over bedrock, and West Antarctica, which contains the marine-based West
Antarctic ice sheet (WAIS). These two ice sheets contain 70 % of the Earth's fresh-
water and have mean elevation of over 3,000 m. While the EAIS generally has been
stable during the Pleistocene, the WAIS disintegrated during Northern Hemisphere
glaciations (Denton et al.
1991
).
9.2
Soil-Forming Factors
9.2.1
Climate, Permafrost, and Active-Layer Thickness
There are three distinct climates in Antarctica. The western Antarctic Peninsula and
the offshore islands (South Shetland and South Orkney Islands) have a subantarctic
maritime climate with mean annual air temperatures ranging from −2 to −4 °C and
mean annual precipitation between 400 and 700 mm (water equivalent) (Table
9.2
).
The coastal regions of East Antarctica have a polar desert climate with a mean
temperature of −10 to −12 °C and a mean annual precipitation of 200-250 mm. The
inland mountains have a cold desert climate with a mean temperature of −20 to
−35 °C and a mean annual precipitation of <50 mm.
