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Antarctica consists of two main areas. East Antarctica (Greater Antarctica), and smaller West Antarctica (Lesser Antarctica) which also has the Antarctic Peninsula.
West Antarctica is an extension of the Andes mountains stretching from South America. It is thought that if the ice sheet were removed, West Antarctica would actually be a collection of islands.
More than 99 percent of Antarctica is covered with ice, this contains about 70 percent of the world's fresh water. The thick ice cover makes it the highest of all continents, with an average elevation of about 2300 m (about 7500 ft).
The highest point on the continent is Vinson Massif 4897 m (about 16 066 feet). The lowest point yet found is the Bentley Subglacial Trench (2499 m/8200 ft below sea level) in West Antarctica, this is a trench in the earth's crust well below sea-level, it is covered with more than 3000 m (more than 9840 ft) of ice and snow. Lower points may exist under the ice, but they have not yet been discovered.
The Eastern and Western halves of Antarctica are separated by the Transantarctic Mountains. This range of mountains stretches across the entire continent, large portions of them being buried under the ice cover. If you stood on the great Antarctic ice sheet all you would see would be ice and snow (and your friend taking a photograph of you standing on the great Antarctic ice sheet). It would be similar to being on the surface of the sea above an underwater mountain range.
It would be far from a continuous smooth sheet though. The ice sheet is continuously moving towards the coast under the influence of gravity.
Glaciers, huge rivers of ice carry the ice from the interior of the continent forming ice shelves at the coasts. Where a glacier is moving, the ice cracks and breaks, underlying rock and different streams meeting that move at different speeds add to the chaos.
This makes the ice sheet very dangerous in places as it is broken up by great crevasse fields with some cracks hundreds of feet deep and frequently covered by flimsy bridges formed of blown snow.
In places, you may see a "Nunatak" an outcrop of rock where one of the taller parts of the Transantarctic mountains peek up through the ice sheet. Like islands in mid-ocean that start as underwater mountains.
Amazingly sometimes such nunataks can be home to birds such as snow petrels that build their nests here. This is despite them being isolated unproductive pieces of rock surrounded by miles and miles of cold sterile ice field.
Nunataks are very useful to geologists as they give a sample of what the rock is like in that area, where most of it is covered by hundreds or thousands of meters of ice.
Large tabular icebergs form at the coasts as the edges of the ice shelves and glaciers calve off into the sea. An ice shelf is formed where a large glacier or even several glaciers begin to float when they meet the sea.
The largest ice shelf, the Ross Ice Shelf, is the size of the American state of Texas. Ice shelves produce the largest icebergs (called tabular as they table-like, flat, on top) as the ice is gently fed onto the surface of the sea before eventually breaking off and becoming free floating.
There are at least two active volcanoes in Antarctica, Mount Erebus (3794 m/12,448 ft) is the highest and has a permanent molten lava lake. The other is on Deception Island, situated just north of the Antarctic Peninsula, a popular stop-off for tourist ships where it is possible to have a warm bath in the volcanically warmed waters while being surrounded by Antarctic ice and penguins.
It is thought that there may be some areas of volcanism under the ice sheet. In some places glaciers and ice streams are flowing very quickly, possibly caused by them being lubricated from underneath by flowing water formed by volcanic activity melting the ice.
Antarctica has no trees or bushes at all, not even the short stunted ones you get in the arctic. Vegetation is limited to about 350 species of mostly lichens, mosses, and algae. There are lush beds of such vegetation in some parts of the Antarctic Peninsula. Lichens have been discovered growing on isolated mountains within 475 km (295 mls) of the South Pole.
In some places bare rocks are colonised by the vibrant red, orange and yellow growth of lichens. Where rock is uncovered by ice for large parts of the summer, green lichens that grow to a few centimetres high can give the impression from a distance of a field of dark grass (albeit a bit tatty). Three species of flowering plants are also found on the Antarctic Peninsula.
In some places in the Antarctic continent such as in the dry valleys, rather than growing on rocks, some algae actually grow in the rock. Conditions are so harsh, particularly from strong, drying winds and from blown sand and dust, that it is easier to live in the rock despite low light levels, than it is exposed at the surface.
There are no land based vertebrate animals in Antarctica. All the vertebrates there are dependent on the sea for feeding or are migratory and leave the continent when the winter arrives.
The largest truly Antarctic land animals therefore are invertebrates only a few of millimetres in size. These animals, mites, ticks and nematode worms tolerate the low temperatures in the winter by becoming frozen in ice under rocks and stones.
They have antifreeze in their bodies and stop all motion and bodily functions while frozen, becoming active again when the ice finally warms up sufficiently to melt. These animals live largely in the Antarctic Peninsula.
The oceans surrounding the continent on the other hand are teeming with great quantities of life. Large numbers of whales feed on the rich marine life, especially krill. Six species of seals and 12 species of birds live and breed in the Antarctic. Crabeater seals are the second most numerous large mammal on the planet after humans and the population of krill has been estimated as outweighing the human population.
The most famous inhabitant of Antarctica is of course the penguin. A flightless bird, but excellent swimmer, penguins live on pack ice and in the oceans around Antarctica. They breed on the land or ice surfaces along the coast and on islands. Best known and most typical are the Adelie and emperor penguins.