Geography of Antarctica

Geography of Antarctica
Continent Antarctica
Coordinates 80°S 90°E / 80°S 90°E / -80; 90
Area Ranked 2nd (unofficially)
 • Total 14,000,000 km2 (5,400,000 sq mi)
 • Land 100%
 • Water 0%
Coastline 17,968 km (11,165 mi)
Borders No land boundaries
Highest point Vinson Massif, 4,897 m (16,066 ft)
Lowest point Bentley Subglacial Trench, −2,555 m (−8,382.5 ft)
Longest river Onyx River, 25 km
Largest lake Lake Vostok, 26,000 sq m (est.)
Climate subantarctic to antarctic
Terrain ice and barren rock
Natural Resources krill, fin fish, crab
Natural Hazards high winds, blizzards, cyclonic storms, volcanism
Environmental Issues depleting ozone layer, rising sea level

The geography of Antarctica is dominated by its south polar location and, thus, by ice. The Antarctic continent, located in the Earth's southern hemisphere, is centered asymmetrically around the South Pole and largely south of the Antarctic Circle. It is surrounded by the southern waters of the World Ocean – alternatively (depending on source), it is washed by the Southern (or Antarctic) Ocean or the southern Pacific, Atlantic, and Indian Oceans. It has an area of more than 14 million km².

Some 98% of Antarctica is covered by the Antarctic ice sheet, the world's largest ice sheet and also its largest reservoir of fresh water. Averaging at least 1.6 km thick, the ice is so massive that it has depressed the continental bedrock in some areas more than 2.5 km below sea level; subglacial lakes of liquid water also occur (e.g., Lake Vostok). Ice shelves and rises populate the ice sheet on the periphery.

Regions

The Princesses Astrid and Ragnhild Coasts
The Banzare, Sabrina, and Budd Law Dome Coasts

Physically, Antarctica is divided in two by Transantarctic Mountains close to the neck between the Ross Sea and the Weddell Sea. Western Antarctica and Eastern Antarctica correspond roughly to the eastern and western hemispheres relative to the Greenwich meridian. This usage has been regarded as Eurocentric by some, and the alternative terms Lesser Antarctica and Greater Antarctica (respectively) are sometimes preferred.

Lesser Antarctica is covered by the West Antarctic Ice Sheet. There has been some concern about this ice sheet, because there is a small chance that it will collapse. If it does, ocean levels would rise by a few metres in a very short period of time.

Volcanoes

There are four volcanoes on the mainland of Antarctica that are considered to be active on the basis of observed fumarolic activity or "recent" tephra deposits: Mount Melbourne (2,730 m) (74°21'S., 164°42'E.), a stratovolcano; Mount Berlin (3,500 m) (76°03'S., 135°52'W.), a stratovolcano; Mount Kauffman (2,365 m) (75°37'S., 132°25'W.), a stratovolcano; and Mount Hampton (3,325 m) (76°29'S., 125°48'W.), a volcanic caldera.

Several volcanoes on offshore islands have records of historic activity. Mount Erebus (3,795 m), a stratovolcano on Ross Island with 10 known eruptions and 1 suspected eruption. On the opposite side of the continent, Deception Island (62°57'S., 60°38'W.), a volcanic caldera with 10 known and 4 suspected eruptions, have been the most active. Buckle Island in the Balleny Islands (66°50'S., 163°12'E.), Penguin Island (62°06'S., 57°54'W.), Paulet Island (63°35'S., 55°47'W.), and Lindenberg Island (64°55'S., 59°40'W.) are also considered to be active.

West Antarctica

West Antarctica on the left.
Typical landscape for the Antarctic Peninsula area, with fjords, high coastal mountains and islands. Click on the image for geographical details.

West Antarctica is the smaller part of the continent, divided into:

Areas

Seas

Ice shelfs

Larger ice shelfs are:

For all ice shelfs see List of Antarctic ice shelves.

Islands

For a list of all Antarctic islands see List of Antarctic and sub-Antarctic islands.

East Antarctica

East Antarctica on the right.

East Antarctica is the larger part of the continent, both the South Magnetic Pole and geographic South Pole are situated here. Divided into:

Areas

Seas

Ice shelfs

Larger ice shelfs are:

For all ice shelfs see List of Antarctic ice shelves.

Islands

For a list of all Antarctic islands see List of Antarctic and sub-Antarctic islands.

Research stations

For a list of all antarctic research stations, see Research stations in Antarctica.

Territorial landclaims

Seven nations have made official Territorial claims in Antarctica.

Dependences and territories

See also

Sources

External links

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