The Antarctic desert is the largest and coldest on Earth, characterized by large temperature fluctuations and almost no precipitation. It is located in the very south of the planet, completely occupying the sixth continent - Antarctica.
Cold deserts of the Earth
Deserts in all people cause associations with heat, endless expanses of sand and small bushes. However, on Earth there are also cold types of them - these are the Arctic and Antarctic deserts. They are called so because of the continuous ice cover and severe frost. Due to the low temperature, the air cannot hold moisture, so it is very dry.
In terms of precipitation, the objects we are considering resemble southern sultry ones, such as the Sahara, which is why scientists gave them the name “cold deserts.”
Zones of the Arctic and Antarctic deserts are the territories of the continents and adjacent islands at the North Pole (Arctic) and South Pole (Antarctic), related, respectively, to the Arctic and Antarctic climatic zones. They consist of glaciers and stones, are practically lifeless, howeverUnder the ice, scientists discover microorganisms.
Antarctica
The territory of the Antarctic desert is 13.8 million square meters, which is the area of the icy 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 coasts consist of glaciers.
The geographical position of the Antarctic deserts that occupy Antarctica is determined not only by the continental zone, but also by the islands located near it. There is also the Antarctic Peninsula, which goes into the depths of the ocean of the same name. The 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 - Erebus - active, is located on an island in the Ross Sea. In coastal areas there are oases that do not have 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 have discovered 140 subglacial lakes. Only one of them does not freeze - Lake Vostok. The eastern part is the largest in terms of territory and the coldest.
Minerals located in the bowels of the mainland: ferrous and non-ferrous metal ore, mica, graphite, coal, there is information about the reserves of uranium, gold and diamonds. ByAccording to geologists, there are oil and gas deposits, but due to the harsh climate, mining is not possible.
Antarctic deserts: climate
The southern mainland has a very harsh and cold climate, which is due to 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 summer - -20 ºС. More comfortable is the coastal zone, where in summer the thermometer reaches -10 ºС, which occurs due to a natural phenomenon called "albedo" - the reflection of heat from the ice surface. The record for the lowest temperature was recorded here in 1983 and amounted to -89.2 ºС.
Precipitation is minimal, about 200 mm for the whole year, it consists only of snow. This is due to extreme cold, which dries out moisture, making the Antarctic desert the driest place on the planet.
The climate here is different: in the center of the mainland 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 have calculated that the amount of frozen water in the form of ice and snow in Antarctica is 90% of the world's fresh water.
One of the obligatory signs 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 mainland to the shore, there is constantlymovement of the ice shelves, during the summer months, parts of the glaciers break off, forming massifs of icebergs that drift in the ocean.
Mainland population
There is no permanently resident population in Antarctica, according to its 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 there are tourist or sports expeditions.
The number of scientists-researchers living at scientific stations in the summer increases to 4 thousand people, in the winter - only 1 thousand. According to historical data, the first settlers here were American, Norwegian and British whalers who lived on the island South Georgia, but whaling has been banned since 1966.
The entire territory of the Antarctic desert is icy silence surrounded by endless expanses of ice and snow.
Biosphere of the southernmost continent
The biosphere in Antarctica is divided into several zones:
- coast of mainland and island;
- offshore oases;
- nunatak zone (mountains near Mirny station, mountainous areas on Victoria Land, etc.);
- ice sheet zone.
The richest in flora and fauna is the coastal zone, where many Antarctic animals live. They feed on zooplankton from sea water (krill). There are no land mammals on the mainland at all.
Only bacteria, lichens and algae, worms and copepods can live in nunataks and coastal oases, birds can occasionally fly in. The most favorable climate zone is the Antarctic Peninsula.
Plant world
The plants of the Antarctic deserts belong to those that appeared millions of years ago, during the existence of the Gondwana continent. They are now limited to a few species of mosses and lichens that scientists estimate are over 5,000 years old.
Flowering plants have been found on the territory of the peninsula and nearby islands, and blue-green algae live in fresh water in oases, which form a crust and cover the bottom of reservoirs.
The number of lichen species is 200, and there are about 70 mosses. Algae usually settle in the summer when snow melts and small reservoirs form, and they can be of various colors, creating bright multi-colored spots that resemble lawns from a distance.
Only 2 species of flowering plants found:
- Colobanthus kito, belonging to the clove family. It is a cushion-shaped grass, decorated with small flowers of white or light yellow shades, about 5 cm in size.
- Antarctic meadow grass from the grass family. 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 orzooplankton in the ocean, and are divided into 2 groups: terrestrial and living in the water.
There are no flying insects, because due to the strong cold wind, they cannot take to the air. However, in the oases there are small ticks, as well as wingless flies and springtails. Only in this area lives the wingless midge, which is the largest terrestrial animal in the Antarctic desert - it is Belgica Antarctica 10-11 mm in size (photo below).
In 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 fauna of Antarctica is also quite limited and is present mainly in the coastal zone:
- 17 types of penguins: Adelie, emperor, etc.;
- seals: Weddell (up to 3 m long), crabeater and predatory leopard seal (reaches 4 m, the skin is stained), sea lion, Ross seals (endowed with vocal abilities);
- whales that eat small crustaceans and icefish live in the ocean;
- huge jellyfish weighing up to 150 kg;
- Some birds settle here in the summer, building nests and raising chicks: gulls, albatrosses, white plover, cormorants, great pipit, petrels, pintail.
The most representative species of animals are penguins, of which the emperor penguins are the most common, living on the coast of the mainland. The growth of these beauties can reach a human (160 cm), and weight - 60 kg.
Another numerous representative of birds is Adélie penguins, the smallest, growing up to 50 cm and weighing no more than 3 kg.
Antarctic ecosystem and conservation
The continental ice deserts and cold waters of the oceans washing Antarctica are an ecosystem inhabited by living organisms that have existed here for thousands of years. The main animal food is phytoplankton.
Due to warming, glaciers and masses of snow in Antarctica are gradually receding, moving closer to the coast. The ice shelves are gradually melting, the soil is gradually exposed, which contributes to creating a more favorable environment for the settlement of plants. However, the introduction of non-native plant species is not at all welcome on the continent.
The ecosystem of Antarctica and the Antarctic desert needs protection from the emergence of "alien" species of life, so every scientist or tourist who comes here undergoes mandatory processing. In the process, it washes away and destroys plant parts or spores.
In accordance with the Treaty, signed by 44 countries of the world, military operations and tests, including nuclear, and the disposal of radioactive waste are prohibited on the territory of Antarctica. Only scientific research is allowed.
