On the edge of our planet lies, like a sleeping princess, a land covered in blue. Ominous and beautiful, she lies in her frosty slumber, in the folds of the mantle of snow, glowing with amethysts and emeralds of ice. She sleeps in the shimmer of the Moon and the Sun, and her horizons are painted in pink, gold, green and blue pastel tones.
Topic: Continents. Antarctica
Lesson: Characteristics of the nature of the continent of Antarctica
Today in class you will learn:
Where is Antarctica located;
What is the relief of the continent;
Why Antarctica is the coldest and windiest continent;
Which living creatures live in Antarctica.
Antarctic- the southern polar region, including Antarctica with its adjacent islands and ocean waters, up to approximately 50-60º S latitude.
Antarctica (the continent opposite the Arctic) is a continent located in the very south of the Earth. The center of Antarctica roughly coincides with the south geographic pole(see Fig. 1). Antarctica is washed by the southern parts of three oceans: the Atlantic, Pacific and Indian, which are conventionally called the Southern Ocean. The continent's area is about 14.4 million km² (of which 1.6 million km² are ice shelves).
Rice. 1. Map of Antarctica
Antarctica- a continent separated from other continents by vast oceanic spaces. The position of the continent near the pole led to the formation of a thick ice cover, the average thickness of which is 2000 m. Due to the thickness of the ice, Antarctica turned out to be the highest continent on Earth. The Antarctic ice sheet contains 80% of the Earth's surface fresh water. In the marginal part of the ice sheet, ice moves towards the ocean at a speed of 20-100 m per year. Its edges break off, forming huge icebergs.
Antarctica - highest continent on earth, the average height of the continent's surface above sea level is more than 2000 m, and in the center of the continent it reaches 4000 meters. Most of this height is made up of the continent's permanent ice sheet, beneath which the continental topography is hidden (see Figure 2).
Rice. 2. Subglacial relief of Antarctica
The continent of Antarctica is core of the Antarctic lithospheric plate. Most of the continent is ancient platform. From the Pacific Ocean in Antarctica, the Pacific “Ring of Fire” is closed by an area of modern folding. Here stretches out mountain range with the active volcano Erebus (see Fig. 3).
Rice. 3. Erebus
The central part of the continent is occupied by the vast Antarctic Plateau. The Transantarctic Mountains range stretches across the eastern part of the continent. The Transantarctic Mountains divide Antarctica into two parts - West Antarctica and East Antarctica, which have different origins and geological structures. To the east is a high, ice-covered plateau. The western part consists of a group of mountainous islands connected by ice. Some of the peaks rising above the monotonous endless fields are young volcanoes. The highest point in Antarctica is Mount Vinson (5140 m).
In West Antarctica there is also the deepest depression of the continent - the Bentley Trench, probably of rift origin. The depth of Bentley's cavity, filled with ice, reaches 2555 m below sea level.
Antarctica is the best place on Earth to collect meteorites, which are clearly visible in the sparkling snow and are perfectly preserved in it.
Antarctica is extremely different harsh, cold climate(see Fig. 4). Near the poles of the planet there are areas of high pressure and low temperatures. The short Antarctic summer is white silence, illuminated by the never-setting sun, and cold. 90% of solar energy is reflected from the snow-white blanket of Antarctica. This is the “refrigerator” of the planet.
In the interior regions, the average daily temperature in summer does not rise above -30 °C, and in winter it drops to -70 °C.
Rice. 4. Climate of Antarctica
The absolute pole of cold is located in East Antarctica, where temperatures down to -89.2 °C were recorded (the area of the Vostok station).
The air is always dry, there is very little precipitation, and “snow dust” falls instead of snow. Cold air sinks down and flows to the shores of the mainland, creating terrible katabatic winds.
Due to the fact that not only the average annual temperature, but also in most areas even summer temperatures in Antarctica do not exceed zero degrees, precipitation there falls only in the form of snow (rain is an extremely rare occurrence). It forms a glacial cover (snow is compressed under its own weight) with a thickness of more than 1700 m, in some places reaching 4300 m. Antarctic ice concentrated up to 90% of all fresh water Earth.
In the 90s of the 20th century, Russian scientists discovered the subglacial non-freezing Lake Vostok - the largest of the Antarctic lakes, having a length of 250 km and a width of 50 km; the lake holds about 5,400 thousand km³ of water.
After more than 30 years of drilling, Russian scientists have penetrated the subglacial Lake Vostok in Antarctica (see Fig. 5).
Rice. 5. Lake Vostok
In Antarctica, hidden under four kilometers of ice, is a unique aquatic ecosystem, isolated from earth's atmosphere and the surface biosphere over millions of years. Its study plays a huge role in constructing a scenario of natural climate change in the coming millennia.
Organic world Antarctica is poor due to its extremely cold living conditions. Terrestrial mammals, which are abundant in the Arctic, are absent in Antarctica. The avifauna is represented by seabirds - penguins, petrels, skuas (about 13 species of nesting birds in total). Their life is inextricably linked with the ocean in which they get their food. Communication with the mainland is carried out only during the summer, during the laying of eggs and the appearance of chicks. Only emperor penguins lay eggs and hatch chicks in the winter. sea ice. Only two species of penguins are widely distributed in Antarctica - the emperor and the Adélie (see Fig. 6).
Rice. 6. Adele
In the Subantarctic there are penguins: king, gentoo (or donkey), golden-haired (macaroni), chinstrap, etc.
The coast of Antarctica and nearby subantarctic islands are inhabited by marine mammals. The islands of the Subantarctic are characterized by a huge seal - the elephant seal. Previously, there lived an eared seal - a fur seal, now almost exterminated. Near the coast of Antarctica live the Weddell seal, the crabeater seal and leopard seal.
Homework
Read § 36. Answer the questions: What is the subglacial relief of the continent? How common are living organisms on the mainland?
Bibliography
MainI
1. Geography. Land and people. 7th grade: Textbook for general education. uch. / A.P. Kuznetsov, L.E. Savelyeva, V.P. Dronov, series “Spheres”. - M.: Education, 2011.
2. Geography. Land and people. 7th grade: atlas. Series "Spheres".
Additional
1. N.A. Maksimov. Behind the pages of a geography textbook. - M.: Enlightenment.
Literature for preparing for the State Exam and the Unified State Exam
1. Tests. Geography. 6-10 grades: Educational and methodological manual / A.A. Letyagin. - M.: LLC "Agency "KRPA "Olympus": Astrel, AST, 2001. - 284 p.
2. Tutorial by geography. Tests and practical assignments in geography / I. A. Rodionova. - M.: Moscow Lyceum, 1996. - 48 p.
3. Geography. Answers on questions. Oral examination, theory and practice / V. P. Bondarev. - M.: Publishing house "Exam", 2003. - 160 p.
4. Thematic tests to prepare for the final certification and the Unified State Exam. Geography. - M.: Balass, ed. House of RAO, 2005. - 160 p.
Antarctica is a continent with extremely low temperatures, located in. Almost its entire territory is covered with ice, with the exception of the area in the west. Difficult living conditions annually attract researchers and tourists.
Read also:
Basic Geographical Information
The area of the continent exceeds 14 million km². The territory is located in the subantarctic and antarctic belt. Antarctica covers all longitudes, and cannot have western and eastern extreme points. There is only the northernmost point, Cape Sifre.
The continent is washed by the Atlantic, Indian and Pacific Oceans, as well as the Amudsen, Ross, Weddell and Bellingshausen seas. The water in the Weddell Sea is the cleanest on the planet. Through it you can see representatives at a depth of up to 70 m.
The coastline is slightly indented, its length exceeds 30 thousand km. The shores most often consist of high ice cliffs and ice shelves. The Arctic Peninsula is the largest on the mainland. It extends north of the southern border. Other large peninsulas include Hut Point, Mawson Peninsula and Edward VII Peninsula. Alexander Land, Deception and Clarence are large islands in Antarctica.
The continent has no permanent population due to the harsh climate. The number of scientists and tourists fluctuates depending on the time of year. 16 countries around the world are conducting research in Antarctica. The region is being studied exclusively for peaceful purposes. States are prohibited from declaring parts of land as their territory. The continent is not divided into time zones or time zones. Scientists focus on the time of their country.
Relief
Antarctica is located on the plate of the same name. As a result of tectonic faults, most of it has risen. The surface is dissected due to dense ice cover. It is difficult for scientists to study the true relief: in some places the thickness of the ice reaches several kilometers.
The average height of the continent reaches 2000 m above sea level. The highest section is the Vinson Massif, highest point which reaches 4892 m above sea level. The Bentley Deep is the lowest point - 2540 m below sea level. The Transarctic Mountains divided the area into West and East Antarctica. In the western part it is more complex, the ridges break through the ice crust. In the east, mountain rises alternate with deep depressions. The Gamburtsev Mountains rest under a layer of ice. The length of the massif is 1300 km, and the highest point is 3390 m. They are comparable in size to the Alps.
Antarctica has both dormant and active volcanoes. Two of them have erupted in the last 200 years. The active volcano Erebus is located to the south of all. A lava eruption was recorded in 2011.
Inland waters
Ice shelves block the way deeper into the continent. In Antarctica you can find ice sheets and mountain glaciers. Their nutrition comes from precipitation. About 2,200 km³ accumulates per year. Ice is consumed by breaking off the shores. 140 lakes have been discovered under the ice. The largest body of water is Lake Vostok, named after the Soviet scientific station. Its depth is 1200 m. Subglacial reservoirs were formed a long time ago: melt water flowed into the depressions and became covered with a crust of ice.
There are no constantly flowing rivers. The Onyx River, located in the Wright Oasis, stretches for 30 km. It flows for two months a year, and with the onset of frost it becomes covered with ice and snow.
Climate
On the continent there is very Cold winter and the same cold summer. The average annual temperature is -60° C. Most of the earth is located in the Antarctic belt, the Antarctic Peninsula lies in the subantarctic zone. Due to its location inside the Antarctic Circle, there is a 24-hour polar night in the winter, and a 24-hour polar day in the summer.
The continent is distant from. It receives less heat due to the large tilt of the earth's axis. The ice surface reflects 80% of light into space. The territory of Antarctica is an icy desert. The amount of snowfall does not exceed ten centimeters per year. Strong winds blow from the highlands. In some areas their speed is 320 km/h.
Flora and fauna:
Vegetable world
There is no vegetation in the Antarctic desert; it covers the outskirts of the continent. Mosses, lichens and mushrooms grow on ice-free land. Unpretentious low-growing bushes are found on the Antarctic Peninsula. Their number includes several dozen species. The flowers are faintly colored because pollination is carried out by the wind, not insects.
Animal world
The islands are home to beetles, butterflies and spiders. Plovers, pipits and several species of ducks nest in South Georgia. Life depends on the seas, whose waters are rich. Animals are represented by pinnipeds and whales: seals, leopard seals, humpback whales, and minke whales. Adélie penguins, emperor penguins and Sclater's penguins live on the northern coast. Flying birds, cormorant, petrel and gull, nest on the rocks.
Minerals
The continent has deposits of coal, copper and iron. Scientists estimate that the volume of oil exceeds the amount of oil in the Arabian Peninsula. Installing special equipment and mining will cause irreparable damage. In 1991, a protocol was drawn up banning mining until 2048.
Ecological situation
The main problem in Antarctica is ozone holes. Thinning of the protective layer threatens with an excess of ultraviolet radiation. The sun melts polar ice. Due to global warming, the air is slowly warming up. Animals have to adapt to new living conditions.
Scientists leave a huge amount of waste that cannot be disposed of. Vehicles and generators running on gasoline and diesel emit soot into the atmosphere. There is virtually no control over mass tourism.
In 2015, the Antarctic Alliance, consisting of Greenpeace, the International Fund for Animal Welfare and the World Wide Fund wildlife put forward demands for the protection of Antarctica. It obliges states to protect the flora and fauna of the mainland. The last untouched territory on Earth has every chance to withstand the destructive actions of man.
Due to the severity of the climate, Antarctica has no permanent population. However, there are scientific stations located there. The temporary population of Antarctica ranges from 4,000 people in summer (about 150 Russians) to 1,000 people in winter (about 100 Russians).
Climate
Antarctica has an extremely harsh cold climate. The absolute pole of cold is located in East Antarctica, where temperatures up to -89.2 °C were recorded (the area of the Vostok station).
Another feature of the meteorology of East Antarctica is katabatic winds, caused by its dome-shaped topography. These stable southerly winds arise on fairly steep slopes of the ice sheet due to the cooling of the air layer near the ice surface, the density of the near-surface layer increases and it flows down the slope under the influence of gravity. The thickness of the air flow layer is usually 200-300 m; because of large quantities icy dust carried by the wind, horizontal visibility in such winds is very low. The strength of the katabatic wind is proportional to the steepness of the slope and reaches its greatest strength in coastal areas with a high slope towards the sea. The katabatic winds reach their maximum strength in the Antarctic winter - from April to November they blow almost continuously around the clock, from November to March - at night or when the Sun is low above the horizon. In summer, during the daytime, due to the heating of the surface layer of air by the sun, katabatic winds along the coast cease.
Despite global warming, temperatures in Antarctica have dropped significantly over the past 35 years. Surface air temperatures drop by 0.7°C every ten years. The overall drop in temperature in Antarctica is a mystery to scientists because most climate change scenarios suggest that the planet's polar regions would be affected by global warming faster and more intensely. In the 21st century, the melting of Antarctica is considered unlikely. It is possible that the Antarctic ice cover will even increase due to large amounts of precipitation. However, the melting of Antarctica is possible in the coming centuries, especially if humanity fails to slow down the process of global warming in advance.
Inland waters
Due to the fact that not only average annual temperatures, but also even summer ones in most areas, temperatures in Antarctica do not exceed zero degrees, precipitation there falls only in the form of snow (rain is an extremely rare occurrence). It forms an ice cover (snow is compressed under its own weight) with a thickness of more than 1700 m, in some places reaching 4300 m. Up to 90% of all fresh water on Earth is concentrated in Antarctic ice.
In the 1990s of the 20th century, Russian scientists discovered the subglacial non-freezing Lake Vostok - the largest of the Antarctic lakes, having a length of 250 km and a width of 50 m; the lake holds about 5400 thousand km? water.
In January 2006, geophysicists Robin Bell and Michael Studinger from the American Lamont-Doherty Geophysical Observatory discovered the second and third largest subglacial lakes, with an area of 2000 km? and 1600 km? respectively, located at a depth of about 3 km from the surface of the continent. They reported that this could have been done earlier if the data from the Soviet expedition of 1958-1959 had been analyzed more carefully. In addition to these data, satellite data, radar readings and measurements of the force of gravity on the surface of the continent were used.
In total, as of 2007, more than 140 subglacial lakes were discovered in Antarctica.
Organic world
The biosphere in Antarctica is represented in 4 “arenas of life”: coastal islands and ice, coastal oases on the mainland (for example, “Banger Oasis”), the Nunataks arena (Mount Amundsen near Mirny, Mount Nansen on Victoria Land, etc.) and the arena ice sheet.
Plants and animals are most common in the coastal zone. Terrestrial vegetation in areas deprived of ice exists mainly in the form of various types of mosses and lichens, and does not form a closed cover (Antarctic moss-lichen deserts). Higher plants are represented by only a few species, the most diverse on the northwestern coast of the Antarctic Peninsula (about a dozen species).
Antarctic animals are entirely dependent on the coastal ecosystem of the Southern Ocean: due to the paucity of vegetation, all significant food chains of coastal ecosystems begin in the waters surrounding Antarctica. Antarctic waters are especially rich in zooplankton, primarily krill. Krill directly or indirectly form the basis of the food chain of many species of fish, cetaceans, squid, seals, penguins and other animals; There are no completely land mammals in Antarctica; invertebrates are represented by ~70 species of arthropods (insects and arachnids) and nematodes living in soils.
Terrestrial animals include seals (Weddell, crabeater, leopard and Ross seals, elephant seals) and birds (several species of petrels, 2 species of skuas, Adélie penguins and emperor penguins).
In the freshwater lakes of continental coastal oases - “dry valleys” - there are oligotrophic ecosystems inhabited by blue-green algae, roundworms, copepods (cyclops) and daphnia, while birds (petrels and skuas) fly here occasionally.
Nunataks are characterized only by bacteria, algae, lichens and severely suppressed mosses; only skuas, following people, occasionally fly onto the ice sheet.
There is an assumption that in the subglacial lakes of Antarctica, such as Lake Vostok, there are extremely oligotrophic ecosystems, practically isolated from the outside world.
In 1994, scientists reported a rapid increase in the number of plants in Antarctica, which seemed to confirm the hypothesis of global warming climate on the planet.
General characteristics of the nature of the continent
Note 1
Today everyone is well aware that the coldest continent on the planet is Antarctica, where the surface cools during the long polar night. IN summer period ice and snow reflect $90$% of solar radiation, so the average daily temperature remains at around $30$ degrees. The lowest temperature is typical for Vostok station. Here is the cold pole of the Southern Hemisphere with a temperature of $89.2 degrees. It is much warmer on the coast - about $0$ degrees in summer, and winter frosts are quite moderate - $10$, -$25$ degrees. The formation of a baric maximum in the center of the continent is associated with cooling. This is an area of high atmospheric pressure, from which constant katabatic winds blow towards the ocean. With a distance from the coast in the range of $600$-$800$ km, they are especially strong. The average annual precipitation on the mainland is $200$ mm, and closer to the center of the continent its amount decreases to several tens of millimeters. Under such climatic conditions, the Antarctic desert, devoid of flora and fauna, formed in the main part of Antarctica. Oases can be considered as centers of life on an icy continent.
Finished works on a similar topic
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The flora of Antarctica is represented by lower plants - $80$ species of mosses, $800$ species of lichens and microscopic algae. Bacteria were discovered in the snow near the Pole of Cold. The fauna is connected to the seas washing the mainland, where in summer dozens of bird species nest on the coastal cliffs - albatrosses, skuas, petrels, penguins. The most characteristic of the mainland are Adélie penguins and large emperor penguins. They can make long journeys deep into the continent. Sperm whales, killer whales, seals, and whales are inhabitants of coastal waters, which are rich in plankton, especially small crustaceans (krill). Previously, Antarctic waters were a hunting area for cetaceans, pinnipeds, and krill, but today, due to severe depletion, many species of animals are under protection.
Antarctica itself and the parts of other continents adjacent to it stand out as a special floristic kingdom. In the Mesozoic era, there was a large center of flora formation here. Changing climatic conditions led to its impoverishment and migration to more favorable northern regions.
Vegetable world
The nature features of Antarctica are explained by the harsh climatic conditions, and the flora of the continent is extremely poor. Algae are numerous, of which there are about 700 species. The plains and coast of the mainland are covered with mosses and lichens in summer.
But there are $2$ species of flowering plants on this harsh land - Colobanthus Quito, belonging to the carnation family, and Antarctic meadow grass. Colobanthus Quito is a low, herbaceous, cushion-shaped plant. Its flowers are very small, pale yellow and white. An adult plant has a height of no more than $5 centimeters and belongs to the cereal family. Both plants grow only on well-warmed rocky soil, despite the fact that they are adapted to harsh conditions and can withstand frost. Their growing season is short.
Blue-green algae, along with bacteria and mosses, cover the bottom of fresh water bodies, forming a dense mucous crust. Algae are among the oldest plants in Antarctica, the fossilized remains of which have been discovered on mineral surfaces. The entire surface of reservoirs in summer is covered with these plants, but they can even settle on melted snow. When in large concentrations, they form bright lawns. These microscopic algae are associated with the illusion of red snowfall, when strong gusts of wind tear them off the surface, lift them into the air and mix them with grains of snow.
In the Antarctic seas, there are giant algae with a length of $150$-$300$ m. They have the common name mactocytas, which means “large-celled”. Indeed, compared to other plants, algae have enormous cell sizes. Colonies of these amazing plants form real underwater forests.
The second most widespread representative of the flora of Antarctica after algae are lichens. These plants, which are a symbiosis of fungi and algae, belong to the lower class. Some representatives of this plant are more than $10$ thousand years old. Managing to grow among the rocks and catching the rare rays of the sun, plants carry out the process of photosynthesis.
The colors of lichens are surprisingly varied - light green, orange, yellow, inconspicuous gray and even completely black. Lichens with black pigment are generally a rare phenomenon on the planet, but in Antarctica they are most common. This is explained by the fact that due to its dark color, the plant absorbs the maximum amount of sunlight and heat. The plant clings to the rocks so tightly that it is impossible to scrape it off with your hands, which is why they are called “scale lichens.” Lichens can also be deciduous, growing like miniature bushes. In the Antarctic climate, lichen growth takes a very long time because it is suppressed by low temperatures and strong winds.
Note 2
Poor species composition The flora of Antarctica is characterized by endemicity due to the long-term isolation of the development of the continent, as a result of which a few plants have adapted to the eternal cold.
Animal world
The natural features of Antarctica have left their mark on the continent’s fauna, which can only live in places where there is vegetation. Animal world The continent is conventionally divided into independent groups - aquatic and terrestrial, and it is important to note that there are no animals permanently living on land in Antarctica.
The terrestrial fauna is very poor; some worms, primitive crustaceans and wingless insects are found. In principle, insects do not need wings here - due to the constantly blowing strong winds, they simply cannot rise into the air. On the island land, scientists found several species of beetles, spiders, and one species of flightless butterfly. Of the birds living on land, the snowy plover, the pipit, and one species of duck are known, which nests on the island of South Georgia. The indigenous inhabitants of Antarctica include Adélie penguins, who spend most of their time in the ocean because the water temperature is higher. They come to the surface only for nesting. Males are very sensitive to the choice of a partner. Having chosen a female, the male brings her a pebble, chosen especially for her. By accepting this gift, the female becomes a companion for life. The chicks gather in a “nursery”, where they spend $2$ a month, and after this period they independently obtain their own food. A penguin's daily diet is $2$ kg of food. Penguins are not the only animals on the mainland.
The largest mammals, cetaceans, live in the seas surrounding Antarctica. They are divided into baleen and toothed whales. Baleen whales are especially well studied because they are the main target of whaling. This subgroup includes blue whales, fin whales, humpback whales, and true whales. The largest of the whales, the blue whale (vomit), together with the fin whale, has the greatest commercial importance. They have an average length of $26m, but the longest whale killed in Antarctic waters reached $35m.
Large whales typically weigh up to $160 tons and produce $20 tons of net blubber. The food for these giants are small crustaceans that live in abundance in cold waters. Toothed whales include sperm whales, bottlenose whales, and killer whales, which are very dangerous predators. With the help of its sharp dorsal fin, the killer whale can inflict dangerous injuries even on a whale. Killer whales hunt in packs and do it successfully and sophisticatedly, attacking fur seals, seals, sperm whales, dolphins, and sea lions.
Killer whales have their own approach to each “prey”; for example, when hunting seals, they use protrusions seabed as an ambush. In a group they dive under an ice floe when hunting penguins in order to immediately knock several individuals into the water. Large whales are hunted mainly by males, at the same time pouncing on the prey and preventing it from rising to the surface of the water. By attacking a sperm whale, killer whales, on the contrary, do not allow it to go into the depths of the sea. These animals are characterized by a developed social structure. They have so-called maternal groups, which include a mother with her calf, her adult sons and several other families headed by relatives of the main killer whale. Such a social group may include up to $20$ individuals who are sufficiently attached to each other. Each pack has its own dialect.
It is interesting that killer whales take care of crippled or old relatives, and their relationships within the pack are more than friendly.
The most common true seals include the Weddell seal, whose length can reach $3$ m. Its main location is a strip of stationary ice. On floating ice There are other types of seals. These include the crabeater seal and the leopard seal, which has a peculiar spotted skin. Of the seals, the largest is the elephant seal, which has already been largely exterminated. On the Antarctic outskirts, the eared seal is found, so named because of its well-defined mane.
The bird world of Antarctica is unique. In summer, petrels, gulls, cormorants, and albatrosses fly here, with a wingspan of up to $3.5 m.
Note 3
In Antarctica, the thesis of evolution – “Survival of the fittest” – is fully confirmed. For the inhabitants of the mainland, life is a daily struggle with low temperatures, a struggle for the most convenient place to obtain food. Strong and formidable to their enemies, the animals of Antarctica are caring and friendly in their pack or colony. The continent's fauna is dangerous and harsh, but magnificent in its own way.
Antarctica is the most cold continent planets. In the conditions of the polar night in winter there is a strong cooling of it. And in summer, the ice and snow cover of Antarctica reflects almost 90% of solar radiation. In inland areas, even in summer, average daily temperatures remain within -30°C, and in winter they reach -70°C. The Vostok station recorded the lowest temperature on our planet (-89.2°C). On the coast of the mainland it is much warmer: in summer the air temperature is about 0°C, and in winter there are moderate frosts - up to -10... -25°C. As a result of strong cooling, a baric maximum is formed in the center of the continent - an area of high atmospheric pressure, from which constant katabatic winds blow towards the oceans. They are especially strong in a strip 600-800 km wide when moving away from the coast. The ice cover in Antarctica is constantly replenished due to snowfall and its subsequent crystallization on the ice surface. On average there is about 200 mm of precipitation per year. And in central regions continental their number is several tens of millimeters. From the inner regions of the ice dome, the ice gradually spreads to the outskirts. In summer, huge blocks of ice break off from the edge of the ice sheet in the form of tabletop and pyramidal icebergs and slide into the water, and then are carried away by currents into the ocean.
The main part of the territory of Antarctica belongs to the zone of Antarctic deserts, which is practically devoid of vegetation and wildlife. Like centers of life on icy continent you can consider the oases of Antarctica. Modern vegetation The continent is represented by lower plants: mosses - 80 species, lichens - 800 species, as well as microscopic algae. And in the region of the Pole of Cold, bacteria were found in the snow. The fauna of Antarctica is associated with ocean waters, washing the mainland. In summer, dozens of bird species nest on the coast and on coastal cliffs - petrels, albatrosses, skua gulls and penguins. Among the latter, the most typical are Adélie penguins, which make long journeys into the interior of the continent, and large emperor penguins. The coastal waters are inhabited by whales, sperm whales, killer whales, different kinds seals. There is a lot of plankton in coastal waters, especially small crustaceans (krill). Fish, whales, pinnipeds, and birds feed on it. Antarctic waters are a catchment area for cetaceans, pinnipeds, nototheniids, and krill. But to date, the marine resources of Antarctica have been greatly depleted and many species of animals, such as whales, are under protection. There is no permanent population in Antarctica. International status its nature is such that it does not belong to any state. Only scientists from all countries of the world can study on the continent scientific research, and some tourist and sports expeditions disturb the icy silence of the vast expanses of the mainland.