Countries of Antarctica. Antarctica used to be tropical

Antarctica is a continent located in the very south of the Earth, the center of Antarctica approximately coincides with the geographic south pole. The mainland Antarctica is washed by the waters of the Atlantic, Indian and Pacific oceans, sometimes unofficially identified as a separate South ocean.

Where is Antarctica

In the southernmost part of our planet is a huge continent covered with eternal ice. Antarctica in the south is not only the coldest, but also the most deserted continent. It is washed by the waters of 13 seas.

1820 - the year of discovery of Antarctica. It was then that the Russian navigators F.F. Bellingshausen and M.P. Lazarev discovered it during a round-the-world Antarctic expedition. The researchers gave the discovered land the definition of "ice continent" and made the first description of the continent.

Rice. 1. Antarctica

The area of ​​Antarctica is about 14,107,000 sq. km (of which ice shelves - 930,000 sq. km, islands - 75,500 sq. km). At the same time, the average height of the surface of Antarctica is the largest of all continents.

In addition, the following features are characteristic of Antarctica:

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• the lowest relative humidity;
• the strongest continuous wind;
• the most intense solar radiation.

Antarctica is an independent territory and does not belong to any state. At the same time, many research stations from around the world can be found on its lands.

Relief

Antarctica is the highest continent on Earth, the average height of the surface of the continent above sea level is more than 2000 m, and in the center of the continent it reaches 4000 meters. The highest point of the continent - 4892 m above sea level - the Vinson Massif in the Ellsworth Mountains.

Huge territories of Antarctica are occupied by a permanent ice sheet, at the base of which there is a continental relief, and only 0.3% (about 40 thousand square kilometers) of its area is free of ice.

The Transantarctic Mountains, crossing almost the entire continent, divide Antarctica into two parts that have different origins and geological structure:

• West Antarctica. It consists of a group of mountainous islands connected by ice.
• East Antarctica. In the east there is a high (ice thickness is 4100 m above sea level) ice-covered plateau.

In West Antarctica there is also the deepest depression of the continent - the Bentley depression, the depth of which is 2555 m below sea level.

Climate

Antarctica has an extremely harsh cold climate. The area is considered the cold pole of the Earth. It should be noted that the winter months in Antarctica (as in the entire southern hemisphere) are June, July and August, and the summer months are December, January and February.

In East Antarctica at the Soviet Antarctic station "Vostok" on July 21, 1983, the lowest air temperature on Earth in the entire history of meteorological measurements was recorded: 89.2 degrees below zero.

Another feature of the meteorology of East Antarctica is katabatic winds due to its dome-shaped topography. Because of a large number wind-blown ice dust, horizontal visibility in such winds is very low.

Rice. 2. Strong katabatic winds

It is not surprising that due to such harsh climatic conditions, there is no permanent population on Antarctica. Research stations operate here throughout the year. In winter, about 1000 people are employed on the continent, in summer their number increases to 4000 people. Recently, tourism has been gaining more and more popularity.

Nature

Plants and animals are most common in the coastal zone. Ground vegetation in ice-free areas exists mainly in the form various kinds mosses and lichens.

Antarctic animals are completely dependent on the coastal ecosystem of the Southern Ocean: due to the scarcity of vegetation, all significant food chains of coastal ecosystems begin in the waters surrounding Antarctica. Antarctic waters are especially rich in zooplankton - the main food source for many species of fish, squid, seals, penguins, and cetaceans.

Rice. 3. Penguins

The main topic of concern to scientists around the world is global warming. As a result of rising temperatures and melting glaciers, tundra began to actively form on the Antarctic Peninsula. According to scientists, in 100 years the first trees may appear in Antarctica.

What have we learned?

From the geography course for grade 7, we learned what place Antarctica occupies in terms of area, where it is located, as well as what features of climate and nature it is characterized by. The mainland, located in the very south of the Earth, is the coldest. On its endless icy deserts, one can only occasionally find sparse vegetation, and animals live only in the coastal zone.

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Antarctica is a mysterious and amazing territory. Of the seven continents, it is the least hospitable and therefore the least explored continent. For your attention - the 10 most interesting facts about him.

10. Its dimensions are constantly changing

The area of ​​the mainland is about 11.7 million square kilometers.

In Antarctica, the sea ice layer is continuously expanding in some regions and shrinking in others. One of the reasons for this is the wind. When it blows for a long time, for example, from the north, the mainland gradually expands in a southerly direction.

These annual fluctuations occur seasonally. The area of ​​​​the mainland (earth) itself is about 11.7 million square kilometers, every summer it is surrounded by about 2.85 million square kilometers of ice. In winter, the continent becomes much larger. Its area reaches almost 18 million square kilometers. To make it easier for you to imagine these numbers, we note that Europe covers only about 9.8 million square kilometers. It can be concluded that every winter the area of ​​the "purely icy" territory of Antarctica exceeds the size of the Old World.

9. The icy continent is great for collecting space debris

Since 1976, US scientists have collected over 16,000 meteorites in Antarctica.

Antarctica is an almost ideal environment for collecting meteorites. In any other place, dark blocks that have flown to us from space mix with the earth and become invisible. Meteorites are mistaken for ordinary stones and, most of the time, no one finds them at all. At the same time, Antarctica is a snow-white continent, covered only with ice and snow. That's why space debris, which fell on its surface, contrasts sharply with the surrounding background, it is very easy to detect it here.

The icy environment also preserves meteorites well - many finds are millions of years old. Therefore, scientists often go here to search for them. Traveling to Antarctica to collect meteorites is the most cost effective. Looking for them in Europe or America is a thankless task. This fact is confirmed in practice: since 1976, scientists from the United States, as part of a program to search for meteorites, have collected more than 16 thousand copies in Antarctica.

8. Annual marathons are held here

Marathons have been held at the Ellsworth base since 2004

The absence of a permanent population is not a hindrance to sports competitions in Antarctica. Unusual marathons have been held at the Ellsworth base since 2004. Participants fly by private jet from South America to a location where average temperature ranges from -17°C to -12°C. The wind blows at a speed of 5-12 m/s. And this is only a small part of the obstacles in the way of athletes. By the way, the marathon takes place at an average altitude of 1000 meters above sea level.

If you do not want the tea in the thermos to freeze after a few minutes, you can take part in the "softer" McMurdo run. It is held on the ice shelf in the Ross Sea. Employees of the McMurdo Research Center (United States of America) often participate in this marathon. But getting to the finish line is not always possible - it all depends on the weather, and it is extremely unpredictable in Antarctica, even in the summer.

7. Tourists come here

About 35,000 tourists visit Antarctica every summer

Opportunities for extreme tourism in Antarctica are countless. You can cross the Arctic Circle, walk through penguin colonies, retrace the paths of early explorers of the continent, go scuba diving, visit research stations, and more. But all this can only be done on the Antarctic Peninsula. It has a relatively mild climate, and receives about the same amount of precipitation per year as Denver. It is jokingly called tropical in comparison to the rest of the continent.

This peninsula, stretching for 1,300 kilometers, is the northernmost and wettest area on the mainland. Here, among the magnificent winter landscapes, penguins, seals and other representatives of the animal world live. Every summer cruise ships deliver about 35 thousand tourists to the Antarctic Peninsula. Of course, this is not so much in comparison with popular resorts, but do not forget that this direction is still very exotic.

6. Antarctica is still new and unknown to us.

Explorers discovered the mainland and began exploring new territories in the early 1800s.

British Captain James Cook, sailing into the Arctic Circle in 1772, did not see the land, but huge floating icebergs and low temperatures testified to the severity of the environment. Explorers discovered the mainland and began exploring new territories in the early 1800s. So, the American captain Joe Davis went to the Antarctic Peninsula to hunt seals in 1821. He was probably the first person to set foot on the new continent.

However, no one managed to reach the South Pole until 1911. The first to do this was the Norwegian Roald Amundsen. Another explorer, Briton Ernest Shackleton, tried to get to the Pole earlier, but had to turn around when the destination was less than 200 kilometers away. The Englishman Robert Scott reached this point a month after Amundsen, but severe weather prevented him from returning home. The high degree of risk did not stop researchers who wanted to visit Antarctica, and flags of different countries were set up at many points on the continent. Over time, their number grew - and it became necessary to resolve issues of ownership.

5. Several countries have serious claims to Antarctica

Argentina, Chile and the UK have claimed Antarctica as their

Naturally, discovering new territories, people want to appropriate them for themselves. But Antarctica is perhaps the only exception. Scientists from all over the world work together on the southernmost continent and conduct scientific research. Seven countries at one time claimed different parts of the continent, but things did not go beyond talk. Only a few states continued to persistently seek the recognition of Antarctica as their territory.

Three countries - Argentina, Chile and Great Britain - managed to declare Antarctica theirs. Of course, they refused to recognize each other's claims. Australia, France, Norway and New Zealand were more modest and claimed only certain parts of the territory. But in 1959, 12 countries signed an agreement under which Antarctica was considered an international territory. Other states later joined in. On the this moment 51 countries agree with the treaty. Nevertheless, the document only slightly cooled the ardor of the states that put forward territorial claims over Antarctica. And today they dream of taking over this continent.

4. This continent has a lot in common with the Sahara

Antarctica is the windiest and driest place on the planet

Antarctica is a real polar desert. It is the highest (on average), windiest and driest area on the planet. In 1983, the lowest temperature on Earth was recorded at the Soviet scientific station Vostok: -89.2 ° C. 98% of the mainland is covered with a layer of ice, which accounts for approximately 70% of the world's fresh water. Its average thickness is 2200 meters, and in East Antarctica it reaches 4800 meters!

What makes this continent similar to the Sahara? First of all, a minimum of life and extremely low average rainfall. It is so cold here that it hardly ever rains. Some areas receive less than 30 millimeters of precipitation per year. There are also zones in which, according to scientists, there has not been rain for more than two million years.

3. There is a bloody waterfall here

Such an unusual appearance of the waterfall is due to the content of a large amount of iron oxide in the water.

Blood Falls is a term used by researchers to describe a stream of intense red water flowing from the Antarctic Taylor Glacier in the Dry Valleys region. Such an unusual view of the waterfall is due to the content of a large amount of iron oxide in the water. Water flows out of a small crack in the ice layer. It turned out that the source is a lake covered with a 400-meter layer of ice. From the waterfall itself, it is several kilometers away. The lake was formed when the Dry Valleys area was flooded. sea ​​water. About 2-4 million years ago, the water receded, and the reservoir turned out to be covered with a layer of ice. It is surprising that the salinity of the water in this source is 4 times higher than that in the oceans. For the same reason, it does not freeze even at -10°C.

By examining the composition of water flows, scientists were able to prove that the deep lake is inhabited by many microorganisms living in conditions of complete absence of oxygen, nutrients from external environment And sunlight required for photosynthesis. The discovered ecosystem allowed astrobiologists to speculate about the possibility of the existence of life in similar conditions on other planets of ours. solar system. For example, under the polar caps of Mars or in the deep oceans of Europa, a satellite of the gas giant Jupiter.

2. Life finds ways to adapt to harsh environments

Many birds live in Antarctica - petrel, albatross, skua

Invertebrates such as nematodes and mites survive on Antarctic land, and the local lakes are full of microbes. Interestingly, some living organisms have developed the ability to survive the most severe cold snaps. When the temperature drops to a critical limit, the cells seem to “freeze” and stop functioning. After warming, they come to life again. Representatives of the fauna are less hardy, so life is in full swing only in areas hidden from constant penetrating winds and with access to water. And, of course, in the depths of the sea.

Penguins, seals, sea lions, giant whales, squid and krill are just some of the large animals that thrive in harsh Antarctic conditions. Many birds also live there - petrel, albatross, skua. The latter cause a lot of inconvenience to expeditions. Predatory skuas often attack other animals or people, often steal food left unattended.

1 Antarctica Used To Be Tropical

50 million years ago, Antarctica was located at tropical latitudes

Researchers of the coldest continent, drilling deep holes in the thickness of centuries-old ice, get the opportunity to see how our planet has changed over time. Surprisingly, they found that palm trees and flowers used to grow on the Antarctic coast with might and main, and the water in the ocean was warm. That is, just over 50 million years ago, Antarctica was located at tropical latitudes.

Fossilized remains of trees and plants that now grow in New Zealand have been found. Scientists also found evidence that in Antarctica grew African baobabs! Today, millions of square kilometers of this continent look like a polar desert. This makes you wonder what changes will happen in the future with the climate - maybe the Sahara will become a new Antarctica, and the polar continent itself will again turn into a warm and inhabited place?

The more we learn about Antarctica, the more new mysteries appear. This amazing snow-white continent is still considered little explored. Harsh conditions make it difficult to carry out scientific research and expeditions, but did difficulties ever stop humanity?

Terrain and ice sheet

Antarctica is the highest continent on Earth, the average height of the surface of the continent above sea level is more than 2000 m, and in the center of the continent it reaches 4000 meters. Most of this height is the permanent ice sheet of the continent, under which the continental relief is hidden and only ~ 5% of its area is ice-free - mainly in West Antarctica and the Transantarctic Mountains: islands, coastal areas, the so-called. "dry valleys" and individual ridges and Mountain peaks(nunataks) rising above the ice surface. The Transantarctic Mountains, crossing almost the entire continent, divide Antarctica into two parts - West Antarctica and East Antarctica, which have a different origin and geological structure. In the east there is a high (the highest elevation of the ice surface is ~4100 m above sea level) ice-covered plateau. The western part consists of a group of mountainous islands connected by ice. On the Pacific coast are the Antarctic Andes, whose height exceeds 4000 m; the highest point of the continent - 4892 m above sea level - the Vinson Massif of the Sentinel Range. In West Antarctica there is also the deepest depression of the continent - the Bentley depression, probably of rift origin. The depth of the Bentley depression, filled with ice, reaches 2555 m below sea level.

The Antarctic ice sheet is the largest on our planet and exceeds the nearest Greenland ice sheet in area by approximately 10 times. It contains ~30 million km³ of ice, that is, 90% of all land ice. It is dome-shaped with increasing steepness of the surface towards the coast, where it is framed in many places by ice shelves. The average thickness of the ice layer is 2500-2800 m, reaching a maximum value in some areas of East Antarctica - 4800 m. The accumulation of ice on the ice sheet leads, as in the case of other glaciers, to the flow of ice into the ablation (destruction) zone, which the coast of the continent (see Fig. 3); ice breaks off in the form of icebergs. The annual volume of ablation is estimated at 2500 km³.

A feature of Antarctica is a large area of ​​ice shelves (low (blue) areas of West Antarctica), which is ~ 10% of the area rising above sea level; these glaciers are the source of icebergs of record size, much larger than those of the outlet glaciers of Greenland; for example, in 2000, the largest known (2005) iceberg B-15 with an area of ​​​​over 10,000 km² broke away from the Ross Ice Shelf. IN winter period(summer in the northern hemisphere) area sea ​​ice around Antarctica increases to 18 million km², and decreases to 3-4 million km² in summer.

The ice sheet of Antarctica was formed about 14 million years ago, which was apparently facilitated by the rupture of the bridge connecting South America and the Antarctic Peninsula, which, in turn, led to the formation of the Antarctic circumpolar current (Western Wind Current) and the isolation of the Antarctic waters from the World Ocean - these waters make up the so-called Southern Ocean.

seismic activity

Antarctica is a tectonically calm continent with low seismic activity; manifestations of volcanism are concentrated in western Antarctica and are associated with the Antarctic Peninsula, which arose during the Andean period of mountain building. Some of the volcanoes, especially island ones, have erupted in the last 200 years. The most active volcano in Antarctica is Erebus. It is called "the volcano guarding the way to the South Pole".

Climate

Antarctica has an extremely harsh cold climate. 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).

Another feature of the meteorology of East Antarctica is the katabatic (katabatic) winds due to its dome-shaped topography. These steady southerly winds occur on rather 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 action of gravity. The thickness of the air flow layer is usually 200-300 m; due to the large amount of ice 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 near-surface air layer by the sun, katabatic winds near the coast stop.

Data on temperature changes from 1981 to 2007 show that the temperature background in Antarctica has changed unevenly. For West Antarctica, as a whole, an increase in temperature is observed, while for East Antarctica, no warming has been detected, and even a certain negative trend has been noted. It is unlikely that in the 21st century the process of melting of Antarctica will increase significantly. On the contrary, the amount of snow falling on the Antarctic ice sheet is expected to increase as temperatures rise. However, due to warming, a more intensive destruction of ice shelves and an acceleration of the movement of outlet glaciers of Antarctica, which throw ice into the World Ocean, are possible.

Inland waters

Due to the fact that not only average annual, 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 (snow is compressed under its own weight) cover with a thickness of more than 1700 m, in some places reaching 4300 m. Up to 90% of the entire fresh water of the Earth is concentrated in the Antarctic ice.

In the 90s of the XX 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 5400 thousand km³ of 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 km² and 1600 km², respectively, located at a depth of about 3 km from the surface of the continent. They reported that this could have been done sooner 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, in 2007, more than 140 subglacial lakes were discovered in Antarctica.

Biosphere

The biosphere in Antarctica is represented in four “arenas of life”: coastal islands and ice, coastal oases on the mainland (for example, the “Banger oasis”), the nunatak arena (Mount Amundsen near Mirny, Mount Nansen on Victoria Land, etc.) and the arena of the ice sheet .

Plants and animals are most common in the coastal zone. Ground vegetation in ice-free areas exists mainly in the form of various types of mosses and lichens and does not form a dense cover (Antarctic moss-lichen deserts).

Antarctic animals are completely dependent on the coastal ecosystem of the Southern Ocean: due to the scarcity 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 for many species of fish, cetaceans, squid, seals, penguins and other animals; There are no completely land mammals in Antarctica, invertebrates are represented by about 70 species of arthropods (insects and arachnids) and nematodes living in soils.

Terrestrial animals include seals (Weddell, crabeater seals, leopard seals, Ross, elephant seals) and birds (several petrel species, two skuas, Adélie penguins and emperor penguins).

In 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 heavily oppressed mosses; only skuas following people occasionally fly onto the ice sheet.

There is an assumption about the presence in the subglacial lakes of Antarctica, such as Lake Vostok, of extremely oligotrophic ecosystems, practically isolated from the outside world.

In 1994, scientists reported a rapid increase in the number of plants in the Antarctic, which seems to confirm the hypothesis of global warming on the planet.

The Antarctic Peninsula with adjacent islands has the most favorable conditions on the mainland. climatic conditions. It is here that the only flowering plants of the region grow - antarctic meadow grass and kito colobanthus.

Exploring Antarctica

The first ship to cross the Antarctic Circle belonged to the Dutch; it was commanded by Dirk Geeritz, who sailed in the squadron of Jacob Magyu. In 1559, in the Strait of Magellan, Geeritz's ship, after a storm, lost sight of the squadron and went south. When it descended to 64° S. sh., there was found high ground. In 1671 La Roche discovered South Georgia; Bouvet Island was discovered in 1739; In 1772, in the Indian Ocean, Yves-Joseph Kerglen, a French naval officer, discovered an island named after him.

Almost simultaneously with the sailing of Kerglen from England, James Cook set off on his first journey to the southern hemisphere, and already in January 1773 his ships Adventure and Resolution crossed the Antarctic Circle at meridian 37 ° 33 ′. e. After hard struggle with ice it reached 67°15′ S. sh., where he was forced to turn north. In December 1773, Cook again went to the southern ocean, on December 8 he crossed it and on the parallel of 67 ° 5′ S. sh. was covered in ice. Having freed himself, Cook went further south and at the end of January 1774 reached 71 ° 15′ S. sh., SW from Tierra del Fuego. Here an impenetrable wall of ice prevented him from going further. Cook was one of the first to reach the south polar seas and, having met solid ice in several places, he announced that it was impossible to penetrate further. They believed him, and for 45 years no polar expeditions were undertaken.

In 1819, the Russian sailors F.F. Bellingshausen and M.P. Lazarev on the military sloops "Vostok" and "Mirny" visited South Georgia and tried to penetrate deep into the Southern Arctic Ocean. For the first time, in January 1820, almost on the Greenwich meridian, they reached 69°21′ S. sh.; then, having gone beyond the polar circle, Bellingshausen passed along it to the east to 19 ° e. D., where he crossed it again and reached in February 1820 again almost the same latitude (69 ° 6 ′). Further to the east, it rose only to 62° parallel and continued on its way along the margin of the floating ice. Then, on the meridian of the Balleny Islands, Bellingshausen reached 64 ° 55 ′, in December 1820 reached 161 ° W. passed the Antarctic Circle and reached 67°15′ S. sh., and in January 1821 reached 69 ° 53′ S. sh. Almost at the 81° meridian, he discovered the high coast of Peter the Great Island, and after going further east, inside the southern polar circle, he discovered the coast of Alexander I Land. Thus, Bellingshausen was the first to complete a full voyage around Antarctica at latitudes from 60° to 70°.

After that, the study of the coast of the continent and its interior began. Numerous studies were done by English expeditions led by Ernest Shackleton (he wrote the book The Most Terrible Campaign about them). In 1911-1912, a real race to conquer the South Pole unfolded between the expeditions of the Norwegian explorer Roald Amundsen and the Englishman Robert Scott. Amundsen was the first to reach the South Pole, a month after him, the party of Robert Scott arrived at the coveted point and died on the way back.

From the middle of the 20th century, the study of Antarctica began on an industrial basis. Numerous permanent bases are being established on the continent by various countries, all year round leading meteorological, glaciological and geological research. On December 14, 1958, the third Soviet Antarctic expedition, led by Evgeny Tolstikov, reached the South Pole of Inaccessibility and established the temporary Pole of Inaccessibility station there.

Population

Due to the harshness of the climate, there is no permanent population in Antarctica. However, scientific stations are 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).

Antarctica has been assigned the Internet top-level domain .aq and the telephone prefix +672.

Opening

Antarctica was officially discovered on January 16 (28), 1820 by a Russian expedition led by Thaddeus Bellingshausen and Mikhail Lazarev, who approached it on the sloops Vostok and Mirny at the point 69°21′ S. sh. 2°14′ W (G) (O) (area of ​​the modern Bellingshausen Ice Shelf). Previously, the existence of the southern mainland (lat. Terra Australis) was asserted hypothetically, it was often combined with South America (for example, on a map compiled by Piri Reis in 1513) and Australia (named after the “southern mainland”). However, it was the expedition of Bellingshausen and Lazarev in the south polar seas, having circled the Antarctic ice around the world, confirmed the existence of the sixth continent.

The first to enter the continental part on January 24, 1895 were the captain of the Norwegian ship "Antarctic" Christensen and the teacher natural sciences Carsten Borchgrevink.

Status of Antarctica

Cape Hanna In accordance with the Convention on Antarctica, signed on December 1, 1959 and entered into force on June 23, 1961, Antarctica does not belong to any state. Only scientific activities are allowed.

The deployment of military installations, as well as the entry of warships and armed vessels south of the 60th degree of latitude, are prohibited. In the 80s of the XX century, Antarctica was also declared a nuclear-free zone, which excluded the appearance of nuclear-powered ships in its waters, and nuclear power units on the mainland. Now the parties to the treaty are 28 states (with the right to vote) and dozens of observer countries.

Mainland Antarctica

The coldest continent on our planet is considered to be Antarctica. Antarctica is also called the part of the world of the planet, which includes the mainland itself and the adjacent islands. In this article, consider Antarctica as a mainland. This continent was discovered by a Russian expedition in January 1820. The mainland is located in the very south of the planet. Translated from Greek, Antarctica means "opposite the Arctic" or "opposite the north." Approximately the center of the mainland falls on the location of the south pole of the Earth. Washed by the continent southern part waters of three oceans: Pacific Ocean, Atlantic Ocean And Indian Ocean, since 2000, this territory of waters has become known as the Southern Ocean. The Southern Ocean is characterized strong winds and storms.

The area of ​​this continent is approximately 14.107 million km2. In terms of its average height (2040 m), Antarctica ranks first among the continents. The only thing to consider is that this height is achieved thanks to glaciers, while the land of this continent is located much lower than this figure. Therefore, the first place in terms of land height is given to the mainland of Eurasia. And in the central part, the ice cover can reach more than 4,000 meters in height. If we compare the amount of ice on Antarctica with the ice reserves on the entire planet, then Antarctica contains 90% of all the ice reserves of the planet. Also in these Ices is stored 80% of the total supply of fresh water on the planet. If all the glaciers of the mainland melt, this will lead to an increase in the water level in all oceans by 60 meters, and Antarctica itself will become an archipelago (cluster of islands).

Relief

Antarctica is the highest continent on Earth, the average height of the surface of the continent above sea level is more than 2000 m, and in the center of the continent it reaches 4000 meters. Most of this height is the permanent ice cover of the continent, under which the continental relief is hidden, and only 0.3% (about 40 thousand km²) of its area is free of ice - mainly in West Antarctica and the Transantarctic Mountains: islands, coastal areas, etc. n. "dry valleys" and individual ridges and mountain peaks (nunataks) rising above the ice surface.

The Transantarctic Mountains, crossing almost the entire continent, divide Antarctica into two parts - West Antarctica and East Antarctica, which have a different origin and geological structure. In the east there is a high (the highest elevation of the ice surface is ~4100 m above sea level) ice-covered plateau. The western part consists of a group of mountainous islands connected by ice. On the Pacific coast are the Antarctic Andes, whose height exceeds 4000 m; the highest point of the continent - 5140 m above sea level - the Vinson Massif in the Ellsworth Mountains. The deepest depression of the continent, the Bentley Basin, is also located in West Antarctica, probably of rift origin. The depth of the Bentley depression, filled with ice, reaches 2555 m below sea level.

Under-ice relief

Research with modern methods made it possible to learn more about the subglacial relief of the southern continent. As a result of the research, it turned out that about a third of the mainland lies below the level of the world ocean, the research also showed the presence of mountain ranges and massifs.

The western part of the continent has a complex relief and large elevation changes. Here are the most high mountain(Mt. Vinson 5140 m) and the deepest depression (Bentley trough −2555 m) in Antarctica. The Antarctic Peninsula is a continuation of the South American Andes, which stretch towards the South Pole, slightly deviating from it to the western sector.

The eastern part of the mainland has a predominantly smooth relief, with separate plateaus and mountain ranges up to 3–4 km high. In contrast to the western part, composed of young Cenozoic rocks, the eastern part is a projection of the crystalline basement of the platform that was previously part of Gondwana.

The continent has relatively low volcanic activity. The largest volcano is Mount Erebus on Ross Island in the sea of ​​the same name.

NASA's subglacial surveys have discovered a crater of asteroid origin in Antarctica. The diameter of the funnel is 482 km. The crater was formed when an asteroid with a diameter of about 48 kilometers (larger than Eros) fell to Earth, about 250 million years ago, in the Permian-Triassic period. The asteroid did not cause severe harm to the nature of the Earth, but the dust raised during the fall led to centuries of cooling and the death of most of the flora and fauna of that era. This crater is by far the largest on Earth.

ice sheet

The Antarctic ice sheet is the largest on our planet and exceeds the nearest Greenland ice sheet in area by approximately 10 times. It contains ~30 million km³ of ice, that is, 90% of all land ice. Due to the gravity of the ice, as studies by geophysicists show, the continent sank by an average of 0.5 km, as evidenced by its relatively deep shelf. The ice sheet in Antarctica contains about 80% of all fresh water on the planet; if it melts completely, global sea levels will rise by almost 60 meters (for comparison: if the Greenland ice sheet melted, ocean levels would rise by only 8 meters).

The ice sheet is dome-shaped with an increase in the steepness of the surface towards the coast, where it is framed in many places by ice shelves. The average thickness of the ice layer is 2500–2800 m, reaching a maximum value in some areas of East Antarctica – 4800 m. The accumulation of ice on the ice sheet leads, as in the case of other glaciers, to the flow of ice into the coast of the continent; ice breaks off in the form of icebergs. The annual volume of ablation is estimated at 2500 km³.

A feature of Antarctica is a large area of ​​ice shelves (low (blue) areas of West Antarctica), which is ~10% of the area that rises above sea level; these glaciers are the source of icebergs of record size, much larger than those of the outlet glaciers of Greenland; for example, in 2000, the largest iceberg B-15 known at the moment (2005) with an area of ​​over 10 thousand km² broke away from the Ross Ice Shelf. In winter (summer in the Northern Hemisphere), the area of ​​sea ice around Antarctica increases to 18 million km², and in summer it decreases to 3–4 million km².

The ice sheet of Antarctica was formed about 14 million years ago, which was apparently facilitated by the rupture of the bridge connecting South America and the Antarctic Peninsula, which, in turn, led to the formation of the Antarctic circumpolar current (Western Winds current) and isolation of Antarctic waters from Oceans - these waters make up the so-called Southern Ocean.

Climate

On the coast, especially in the area of ​​the Antarctic Peninsula, the air temperature reaches -10 -12 C in summer, and on average in the warmest month (January) it is 1 C, 2 C.

In winter (July) on the coast, the average monthly temperature ranges from -8 on the Antarctic Peninsula to -35 C at the edge of the Ross Ice Shelf.

Due to the predominance of descending currents, the relative air humidity is low (60–80%), near the coast and, especially in the Antarctic oases, it decreases to 20 and even 5%. Relatively little cloud cover. Precipitation falls almost exclusively in the form of snow: in the center of the mainland, their amount reaches 30–50 mm per year, in the lower part of the continental slope it increases to 600–700 mm, slightly decreases at its foot (up to 400–500 mm) and again increases by some ice shelves and on the northwestern coast of the Antarctic Peninsula (up to 700–800 and even 1000 mm). Due to strong winds and heavy snowfalls, blizzards are very frequent.

Despite global warming, over the past 35 years, the temperature in Antarctica has dropped significantly. The air temperature at the surface decreases by 0.7 °C every ten years. The overall decrease in temperature in Antarctica is a mystery to scientists, since most climate change scenarios assume that the polar regions of the planet should be exposed to global warming faster and more intensively. In the 21st century, the process of melting of Antarctica is considered unlikely. Perhaps due to the high amount of precipitation, the Antarctic ice sheet will even increase. However, the melting of Antarctica is possible in the following 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, but even summer temperatures 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 the entire fresh water of the Earth is concentrated in the Antarctic ice.

In the 1990s of the XX century, Russian scientists discovered the ice-free ice-free Vostok Lake - the largest of the Antarctic lakes, having a length of 250 km and a width of 50 km; the lake holds about 5400 thousand km³ of 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 km² and 1600 km², respectively, located at a depth of about 3 km from the surface of the continent. They reported that this could have been done sooner if the data from the 1958–1959 Soviet expedition 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, in 2007, more than 140 subglacial lakes were discovered in Antarctica.

Flora of Antarctica

The flora of Antarctica, due to special climatic conditions, is extremely poor. Most of all there are algae - about 700 species. The coast of the mainland and its plains, free from ice, are covered with mosses and lichens. And here flowering plants only two types. These are colobanthus kito and antarctic meadow grass.

Colobanthus kito belongs to the clove family. It is a cushion-shaped herbaceous plant with small white and pale yellow flowers. The growth of an adult plant does not exceed 5 cm.

Meadow antarctic belongs to the grass family. It grows only in areas of land that are well lit by the sun. Meadow bushes can grow up to 20 cm. The plant itself tolerates frost very well. Frost does not harm the plant even during flowering.

All plants of Antarctica have successfully adapted to the eternal cold. Their cells contain little water, and all processes are very slow.

Animal world of Antarctica

The peculiarity of the fauna of Antarctica is directly related to its climate. All animals live only where there is vegetation. Despite the severity of climatic conditions, a person was even born in Antarctica (this happened in 1978). And excavations have shown that dinosaurs once lived on this mainland.

Conventionally, all Antarctic animals can be divided into two groups: terrestrial and aquatic, and there are no completely terrestrial animals in Antarctica.

The waters around the mainland are rich in zooplankton, which is the main food for whales and seals, fur seals and penguins. Ice fish also live here - amazing creatures that have adapted to life in icy water.

Of the large animals, blue whales most often visit the shores of Antarctica, which are attracted by the abundance of shrimp. IN fresh waters lakes are inhabited by roundworms and blue-green algae, copepods and daphnia are found.

The world of birds is represented by penguins, arctic terns and skuas. There are 4 species of penguins in Antarctica. The largest population is the emperor penguins. Fly on southern mainland and petrels.

There are also few mammals. Basically, these are animals that can live on land and in water. Most of all in Antarctica seals. Leopard seals, elephant seals and Rossa also live on the coast. Of the dolphin family, there are only small groups of black-and-white or sand-colored dolphins, known among whalers under the name "sea cows".

That's who there are a lot of - so it's invertebrate arthropods. In Antarctica, 67 species of ticks and 4 species of lice were found. There are fleas, lice and the ubiquitous mosquitoes. And wingless jingle-black mosquitoes live only in Antarctica. These are the only endemic insects that can be classified as completely land animals. Most of insects and invertebrates were brought to the shores of the southern continent by birds.

Sights of Antarctica

• Glaciers of Antarctica. Paradise Harbor is a popular destination in Antarctica. Watching huge blocks of age-old glaciers and icebergs from the sides of inflatable boats is a spectacular sight.
• Islands of Antarctica. There is a place in Antarctica that is of particular interest to volcanologists, hunters and travelers - Deception Island. It is an extinct volcano and has the shape of a horseshoe.
• bloody waterfall. An unusual attraction for icy Antarctica is the Bloody Falls. Streams of red water, with a high concentration of salts and iron oxide, flow down the surface of the glacier, originating in one of the Antarctic lakes.
• Church of the Whalers. Another well-known place in Antarctica is the Whaling Church, built in neo-Gothic style back in 1913 next to the whaling station. Despite the full functionality, after the restoration in 1998, it is practically not used today, but it has been preserved for posterity as a monument.
• Mountains of Antarctica. The Queen Maud mountain range rises 3,000 meters above sea level. The system was discovered by the expedition of R. Amundsen, named after the Norwegian queen.
• Drake Passage. Drake Passage was named after an English pirate sailor who sailed in this place in the middle of 1578. It is the deepest and widest strait in the world.
• Catholic Church. The Catholic Church, located in an ice cave, is located at the Belgrano Arctic research base. This is the "coldest" temple among all religions known on earth.
• Penguins in Antarctica. And, of course, the most important and pretty attraction of Antarctica is the king penguins, without which it is impossible to imagine this region.

Tourism in Antarctica

Given the extremely difficult climatic conditions in Antarctica, tourism here is completely dependent on the season and is possible only for a few months of the year. In general, this is the period from November to March, however, certain types of tours to Antarctica are held only at the "crown" of the southern hemisphere summer.

Cruises to the near-Antarctic regions (South Shetland and Falkland Islands, the South Georgia Archipelago, the Antarctic Peninsula and the continental seas) are held from November to March. Cruises in the eastern part of Antarctica, where the huge Ross Ice Shelf and memorable places dedicated to the history of the conquest of the mainland are located, are available in January-February, when the ice melts here. Conquest of the South Pole by plane (option: by plane and skis) is possible only at the peak of the Antarctic summer - in December-January.

Video

Sources

https://tonkosti.ru/Antarctica https://seasons-years.rf/nature of Antarctica.html http://chudesnyemesta.ru/antarktida-dostoprimechatelnosti/ http://veter-s.ru/article/antarktida-opisanie -place