The Antarctic Desert is the largest andcold on Earth, characterized by large temperature changes and the almost complete absence of precipitation. It is located on the very south of the planet, completely occupying the sixth continent - Antarctica.
Deserts in all people are associated with heat,vast expanses of sand and small shrubs. However, there are also cold species on the Earth - these are arctic and antarctic deserts. They are called so because of the solid ice cover and heavy frost. Due to the low temperature, the air cannot hold moisture, so it is very dry.
By the amount of precipitation, the objects we consider resemble southern sultry, such as the Sahara, so scientists gave them the name "cold deserts".
The zones of the Arctic and Antarctic deserts arethe territories of the continents and adjacent islands at the North Pole (Arctic) and the South (Antarctic), belonging, respectively, to the Arctic and Antarctic climatic zones. They consist of glaciers and stones, are practically lifeless, but under the ice, scientists detect microorganisms.
The territory of the Antarctic desert is 13.8 millionsq. m., 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: Pacific, Atlantic and Indian, the shores consist of glaciers.
The geographical position of the Antarctic deserts,which occupy Antarctica, is determined not only by the mainland, but also by the islands located near it. There is also the Antarctic Peninsula, which penetrates deep into the ocean of the same name. On the territory of Antarctica lie the Trans-Antarctic Mountains, which divide the continent into 2 parts: the western and the eastern.
The western half is located on the Antarcticplatform and is a mountainous terrain with a height of almost 5 km. Volcanoes are located in this part, one of which, Erebus, is active, is located on an island in the Ross Sea. In the coastal areas there are oases where there is no ice. These small plains and mountain peaks, called nunataks, have an area of 40 thousand square meters and are located on the coast of the Pacific Ocean. On the mainland there are lakes and rivers that appear only in summer. Total scientists found 140 subglacial lakes. Only one of them does not freeze - Lake Vostok. The eastern part is the largest in the territory and the coldest.
Minerals in the bowelsmainland: ferrous and non-ferrous 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, but because of the harsh climate, mining is not possible.
On the southern continent is very harsh and cold climate, which is caused by the formation of cold and dry air flow. Antarctica is located in the Antarctic climate zone of the Earth.
In winter, temperatures can reach -80 ºС, insummertime is -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.
The amount of precipitation is minimal,about 200 mm for the whole year, they consist only of snow. This is due to the extreme cold that dries the moisture, which makes it possible to call the Antarctic desert the dryest place on the planet itself.
Климат здесь имеет отличия:in the center of the continent, the precipitation is less (50 mm), colder, the wind is less intense on the coast (up to 90 m / s), and the 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 world's total freshwater supply.
One of the essential signs of the desert is storms. Here they also happen, only snow, and the wind speed during the elements is 320 km / h.
In the direction from the center of the continent to the coast, ice shelf movement constantly occurs, during the summer months parts of the glaciers break off, forming iceberg tracts that drift in the ocean.
В Антарктиде нет постоянно проживающего population, by international status, it does not belong to any state. On the territory of the zone of the Antarctic desert are located only scientific stations, where scientists are engaged in research. Sometimes there are tourist or sports expeditions.
Number of research scientists residing inscientific 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 of South Georgia, but since 1966 the hunt for whales has been prohibited.
The whole territory of the Antarctic desert is icy silence surrounded by endless expanses of ice and snow.
The biosphere in Antarctica is divided into several zones:
Самой богатой по флоре и фауне является the seaside zone in which many Antarctic animals live. They feed on zooplankton from sea water (krill). There are no land mammals on the mainland at all.
Nunataks and coastal oases can liveonly bacteria, lichens and algae, worms and copepods, birds can occasionally fly in. The most climate-friendly zone is the Antarctic Peninsula.
Растения антарктических пустынь относятся к тем, that appeared millions of years ago, back in the days of the Gondwana continent. Now they are limited to several species of mosses and lichens, which, according to scientists, are more than 5 thousand years old.
On the territory of the peninsula and the nearby islands, flowering plants were found, and in fresh water in the oases live blue-green algae, which form a crust and cover the bottom of the reservoirs.
The number of lichen species is 200, andThere are about 70 mosses here. Algae usually settle in the summer when snow is thawed and small water bodies form, and they can be of various colors, creating bright multi-colored spots that resemble lawns from afar.
Only 2 types of flowering plants were found:
The fauna of Antarctica is very poor due to the coldclimate 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 of the strongcold wind they can not rise into the air. However, in the oases there are small mites, as well as wingless flies and springtails. It is only in this region that the wingless midge lives, which is the largest land animal of the Antarctic desert - this Belgica antarctica size 10-11 mm (photo below).
In freshwater bodies in the summertime, one can find the simplest representatives of the fauna, as well as rotifers, nematodes, and lower crustaceans.
The animal world of Antarctica is also quite limited and is present mainly in the coastal zone:
The most representative kind of animal ispenguins, of which the most common imperial living on the coast of the mainland. The growth of these handsome men can reach a human (160 cm), and weight - 60 kg.
Another numerous representative of birds is Adelie penguins, the smallest, growing up to 50 cm and body weight not more than 3 kg.
Mainland ice deserts and cold watersThe oceans surrounding Antarctica are an ecosystem inhabited by living organisms that have existed here for thousands of years. The main animal food is phytoplankton.
Due to the warming of glaciers and the mass of snow inAntarctica is gradually receding, moving closer to the coast. Ice shelves gradually thawed, the soil is gradually exposed, which contributes to the creation of a more favorable environment for the settlement of plants. However, the appearance of non-native species of plants is not at all welcomed on the continent.
Экосистема Антарктиды и антарктической пустыни needs to be protected from the appearance of “alien” species of life, therefore, every visiting scientist or tourist is subject to mandatory processing. In the process of its occurrence, the washing and destruction of parts of plants or spores occurs.
In accordance with the Agreement signed by 44countries of the world, on the territory of Antarctica, military operations and tests, including nuclear, and the disposal of radioactive waste are prohibited. Only scientific studies are allowed.