The Antarctic Desert is the largest and coldest on Earth, characterized by large temperature differences and an almost complete absence of precipitation. It is located in the very south of the planet, fully occupying the sixth continent - Antarctica.
Earth's Cold Deserts
Deserts in all people are associated with heat, endless expanses of sand and small shrubs. However, there are cold species on Earth - these are arctic and antarctic deserts. They are called so because of the continuous ice cover and severe frost. Due to the low temperature, air cannot retain moisture, therefore it is very dry.
By the amount of precipitation, the objects we are considering are reminiscent of sultry southern ones, such as the Sahara, which is why scientists gave them the name “cold deserts”.
The zones of the Arctic and Antarctic deserts are the territories of the continents and adjacent islands at the North Pole (Arctic) and South (Antarctic), relating, respectively, to the Arctic and Antarctic climatic zones. They consist of glaciers and rocks, they are almost lifeless, but under the ice, scientists find microorganisms.
Antarctica
The territory of the Antarctic desert is 13.8 million square meters, which is the area of the ice continent, which is located in the southern polar part of the world. From different sides it is washed by several oceans: the Pacific, Atlantic and Indian, the coast consists of glaciers.
The geographical position of the Antarctic deserts that occupy Antarctica is determined not only by the mainland zone, but also by the islands located near it. There is also the Antarctic Peninsula, protruding into the depths of the ocean of the same name. Transantarctic mountains lie on the territory of Antarctica, dividing the mainland into 2 parts: western and eastern.
The western half is located on the Antarctic platform and is a mountainous area almost 5 km high. Volcanoes are located in this part, one of which is Erebus - active, located on an island in the Ross Sea. In coastal areas there are oases on which there is no ice. These small plains and mountain peaks, called nunataks, have an area of 40 thousand square meters, located on the Pacific coast. On the mainland there are lakes and rivers that appear only in the summer. In total, scientists discovered 140 subglacial lakes. Only one of them does not freeze - Lake Vostok. The eastern part is the largest in territory and the coldest.
Minerals located in the bowels of the mainland: ferrous and non-ferrous metal ores, mica, graphite, coal, there is information about the reserves of uranium, gold and diamonds. According to the assumptions of geologists, there are deposits of oil and gas, however, due to the harsh climate, mining is not possible.
Antarctic Deserts: Climate
The southern continent has a very harsh and cold climate, which is caused by the formation of cold and dry air currents. Antarctica is located in the Antarctic climate zone of the Earth.
In winter, the temperature can reach -80 ºС, in the summer - -20 ºС. The coastal zone is more comfortable, where in the summer the thermometer reaches -10 ºС, which occurs due to a natural phenomenon called “albedo” - heat reflection from the ice surface. The record for the lowest temperature was recorded here in 1983 and amounted to -89.2 ºС.
The amount of precipitation is minimal, about 200 mm for the whole year, they consist only of snow. This is due to the severe cold, which dries moisture, which allows the Antarctic desert to be called the driest place on the planet.
The climate here has differences: in the center of the continent there is less precipitation (50 mm), it is colder, on the coast the wind is less intense (up to 90 m / s), and precipitation is already 300 mm per year. Scientists estimate that the amount of frozen water in the form of ice and snow in Antarctica is 90% of the total world supply of fresh water.
One of the indispensable features of the desert is storms. Here they also happen, only snowy, and the wind speed during the elements is 320 km / h.
In the direction from the center of the continent to the coast, the movement of ice shelves constantly; in the summer months, parts of the glaciers break off, forming massifs of icebergs that drift in the ocean.
Mainland population
There is no permanent resident population in Antarctica; by international status, it does not belong to any state. On the territory of the Antarctic desert zone, there are only scientific stations where scientists are engaged in research. Sometimes tourist or sports expeditions are held.
The number of scientists living in scientific stations in summer increases to 4 thousand people, in winter - only 1 thousand. According to historical data, the first settlers here were American, Norwegian and British whalers who lived on the island of South Georgia, but with 1966, whaling is banned.
The entire territory of the Antarctic desert is icy silence surrounded by vast expanses of ice and snow.
The biosphere of the southernmost continent
The biosphere in Antarctica is divided into several zones:
- coast of the mainland and islands;
- oases located offshore;
- Nunatak zone (mountains near Mirny station, mountainous areas on Victoria Land, etc.);
- ice sheet area.
The richest in flora and fauna is the coastal zone, in which many Antarctic animals live. They feed on zooplankton from seawater (krill). There are no land mammals on the mainland.
Only bacteria, lichens and algae, worms and copepods can live in nunatacks and coastal oases; birds can occasionally fly in. The most favorable climate zone is the Antarctic Peninsula.
Vegetable world
Plants of the Antarctic deserts are those that appeared millions of years ago, even during the existence of the Gondwana continent. Now they are limited to several types of mosses and lichens, which, according to scientists, are over 5 thousand years old.
Flowering plants were found on the peninsula and nearby islands, and blue-green algae live in fresh water in oases, which form a crust and cover the bottom of ponds.
The number of lichen species is 200, and there are about 70 mosses. Algae usually settle in the summer when snow melts and small ponds form, and they can be of various colors, creating bright multi-colored spots that resemble lawns from afar.
Only 2 species of flowering plants were found:
- Colobanthus Quito, belonging to the clove family. This grass is in the form of a "pillow", decorated with small flowers of white or light yellow shades, about 5 cm in size.
- Antarctic meadow from the cereal family. It grows in sunny areas, tolerates frost well, grows up to 20 cm.
Ice Desert Animals
The fauna of Antarctica is very poor due to the cold climate and lack of food. Animals live only in places where there are plants or zooplankton in the ocean, and are divided into 2 groups: terrestrial and living in water.
There are no flying insects, because due to the strong cold wind they cannot rise into the air. However, in oases small ticks are found, as well as wingless flies and springtails. Only in this area does the wingless midge live, which is the largest land animal of the Antarctic desert - is Belgica Antarctica 10-11 mm in size (photo below).
In the freshwater reservoirs in the summer you can find the simplest representatives of the fauna, as well as rotifers, nematodes and lower crustaceans.
Antarctica animals
The wildlife of Antarctica is also quite limited and is present mainly in the coastal zone:
- penguins of 17 species: Adele, imperial and others;
- seals: Weddell (up to 3 m long), crab eaters and predatory leopard seal (reaches 4 m, the skin is colored with spots), sea lion, Ross seals (endowed with vocal data);
- whales feeding on small crustaceans and ice fish live in the ocean;
- huge jellyfish reaching 150 kg of weight;
- some birds settle here in the summer, creating nests and rearing chicks: gulls, albatrosses, white plover, cormorants, large skate, petrels, and pintail.
The most representative species of animals are penguins, of which the most common are emperors living on the coast of the mainland. The growth of these beauties can reach human (160 cm), and weight - 60 kg.
Another numerous representative of the birds is the Adelie penguins, the smallest, growing up to 50 cm and body weight not more than 3 kg.
