Henryk Arctowski Polish Antarctic Station

An Antarctic oasis is a large area naturally free of

snow Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water througho ...

and ice in the otherwise ice-covered continent of

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

Geology

In Antarctica there are, in addition to mountaintops and

nunatak A nunatak (from Inuit language, Inuit ) is the summit or ridge of a mountain that protrudes from an ice field or glacier that otherwise covers most of the mountain or ridge. They often form natural pyramidal peaks. Isolated nunataks are also cal ...

s, other natural snow- and ice-free areas often referred to as "Antarctic oases" or "dry valleys". These areas are surrounded by the

Antarctic ice sheet The Antarctic ice sheet is a continental glacier covering 98% of the Antarctic continent, with an area of and an average thickness of over . It is the largest of Earth's two current ice sheets, containing of ice, which is equivalent to 61% of ...

or, in coastal areas, are situated between the ice sheet and the Antarctic ice shelves. Antarctic oases and dry valleys develop in areas with particular regional weather patterns and geography. These areas have very low

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

and

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

. Although these areas are very cold, sufficient solar energy is absorbed by the ground to melt what little snow does fall, or else it is scoured or sublimated by katabatic winds, leaving the underlying rock exposed. Despite usually extreme

arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ...

ity, some plants, in the form of

bryophyte Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...

s and

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s, can survive in Antarctic oases.

Geography

The larger oases (with their respective areas) are: *

McMurdo Dry Valleys The McMurdo Dry Valleys are a row of largely Antarctic oasis, snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of ...

(approx. ),

Victoria Land Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78th parallel south, 78°00'S, and westward from the Ross Sea to the edge of the Ant ...

Cape Hallett Cape Hallett is a snow-free area (Antarctic oasis) on the northern tip of the Hallett Peninsula on the Ross Sea coast of Victoria Land, East Antarctica. Cape Adare lies to the north. History In 1956, during Operation Deep Freeze II, was damag ...

, northern

* Bunger Hills (approx. ), between Wilkes Land and

Queen Mary Land Queen Mary Land or the Queen Mary Coast () is the portion of the coast of Antarctica lying between Cape Filchner, in 91° 54' E, and Cape Hordern, at 100° 30' E. It is claimed by Australia as part of the Australian Antarctic Territory. It ...

* Holme Bay, Mac. Robertson Land *

Vestfold Hills The Vestfold Hills are rounded, rocky, coastal hills, in extent, on the north side of Sorsdal Glacier on the Ingrid Christensen Coast of Princess Elizabeth Land, Antarctica. The hills are subdivided by three west-trending peninsulas bounded by n ...

(approx. ),

Princess Elizabeth Land Princess Elizabeth Land is the sector of Antarctica between longitude 73rd meridian east, 73° east and Cape Penck (at 87°43' east). The sector is claimed by Australia as part of the Australian Antarctic Territory, although this claim is not wi ...

* Larsemann Hills,

* Stillwell Hills (approx. ),

Kemp Land Kemp Land is a thin sliver of Antarctica including, and lying inland from, the Kemp Coast. Part of the Australian Antarctic claim, it is defined as lying between 56° 25' E and 59° 34' E, and, as with other sectors of the Antarctic, is deemed ...

* Schirmacher Oasis (approx. ), Princess Astrid Coast,

Queen Maud Land Queen Maud Land () is a roughly region of Antarctica Territorial claims in Antarctica, claimed by Norway as a dependent territory. It borders the claimed British Antarctic Territory 20th meridian west, 20° west, specifically the Caird Coast, ...

References

External links

About Antarctic oases and Dry valleys, British Antarctic Survey
Oases of Antarctica

Geology

Geography

References

Further reading

External links