"Life Study" - Smoking, alcohol. Food. Rest, sleep. Sports and walks. Progress of the study. Synthetic coolant indicator. Definition of healthy lifestyle. Results. Giving up bad habits is quite difficult in the modern world. Young people adhere to a healthy lifestyle whenever possible. Healthy lifestyle indicator: results. Study of the lifestyle of students of the Preparatory Department...
“Research methods in biology” - Botany zoology mycology microbiology anthropology. Connection with other sciences. Lesson effectiveness: Biology is the theoretical basis of special disciplines for: Borderline disciplines: Signs of science: Your version of a scientific experiment: Updating knowledge. There was a need to classify and systematize natural objects.
“Nature of Antarctica” - The uniqueness of the nature of Antarctica. 1. Geography: Entertaining materials for lessons and extracurricular activities in grades 6-8 / Comp. The richness of the organic world of the ocean. Seal. Low pressure. It is useless to shout, since the roar of the hurricane drowns out everything. Southern parts of the oceans. Work plan: Checking. Antarctic mountains.
“Flora and fauna of Antarctica” - Krill. Flora and fauna of Antarctica. Manifesto for the protection of Antarctica. Anemones. Penguins. Lichens and mosses. Adele. Imprints of ancient ferns. Amazing phenomena in Antarctica “Rusty Falls” “Red Snow”. Sea Elephant. Rotifer. Plankton. Seals. Killer whale. Undersea world. Antarctica continent.
“Lesson Antarctica” - Many countries took part in the research of Antarctica, incl. And our country. A lesson in learning new material. Modern exploration of Antarctica. Lesson stages. Discovery of Antarctica. Antarctica. Tourism and Antarctica. Put together the history of the discovery and exploration of Antarctica in chronological order. What oceans wash Antarctica.
The article talks about the current pace of exploration of the territories of Antarctica. Gives an understanding of the importance of the research being carried out.
Modern exploration of Antarctica
In the first half of the 20th century, exploration of Antarctica was sporadic. However, since the second half of the 50s the situation has changed.
Polar scientists are engaged in research activities in such areas as:
- meteorology;
- physics;
- biology;
- hydrology;
- glaciology.
To prevent plagiarism and copying of research, the international community established the International Committee for the Coordination of Antarctic Research.
Thanks to active research, in the 21st century information about the climatic features of the continent became available to people. The specifics of its geology are known, and the features of the sea are being studied.
The field of science that studies ice sheets is called glaciology.
Rice. 1. The work of a glaciologist.
Research in the field of ice research is currently underway on the mainland. Specialists acquire knowledge regarding the characteristics of the movement of Antarctic ice, their speed, thickness, and physical and chemical properties.
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Rice. 2. Study of the mainland's waters.
These scientific researches made it possible to recreate the picture of the Ice Age. Based on the research, calculations are made that will make it possible to use continental ice as a source of fresh water.
Antarctica is of considerable interest to geologists. Scientists managed to prove the fact that the ice of Antarctica arose earlier than the ice sheets of the Northern Hemisphere.
The studied areas of land not covered with ice are called oases. Most of them are located along the coast of the continent. The total area of these territories is over 40 thousand square meters. km, or less than 1% of the area of the entire Antarctica.
Modern events in Antarctica
The events that are happening now in Antarctica can rightly be called relevant - they are of particular interest to the entire planet. The endless lands of the continent hide under the ice thickness natural resources of interest to humanity. Recent studies have confirmed that the continent's geological composition is similar to South Africa. There is an assumption that impressive deposits of precious metals and uranium are hidden in the bowels of the Antarctic land.
Rice. 3. Geological research.
Fossil exploration in Antarctica is very active today. Over the past decades, scientists have made a colossal breakthrough in the study of the icy continent.
Many new territories were explored, and the specific geological, biological, and oceanological structure of the continent was discovered.
This kind of research activity continues at this moment, especially since an increasing number of scientists around the world are showing interest in the continent.
Antarctica- the only continent, unusual in its uniqueness of nature. Polar explorers called it icy, silent, deserted, mysterious, white. In winter, Antarctica plunges into the darkness of the polar night, and in summer the Sun does not fall below the horizon, illuminating the icy desert at midnight. At the South Pole, the sun rises and sets only once a year.
This continent is the highest and coldest. The strongest winds on Earth are observed here. There is no permanent population here. The ice of Antarctica contains 80% of the planet's fresh water. The history of the discovery and exploration of the continent is peculiar.
Antarctica and Antarctica
The nature of Antarctica is inextricably linked with the nature of the southern parts of the Pacific, Atlantic and Indian oceans and together with them forms a single whole. Large areas extending shallowly into the land of the seas are covered with ice shelves. These glaciers are a continuation of the continental ice shell.
Antarctic- this is the southern polar region, including Antarctica with its adjacent islands and the southern parts of the oceans up to approximately 50 - 60 ° S. w. The name “Antarctica” comes from the Greek word “anti” - against, i.e. lying opposite the northern polar region of the globe.
Physiographic location
Almost the entire continent is located within the Antarctic Circle. Antarctica is separated from other continents by vast oceanic expanses. The geographical position of the continent near the pole led to the formation of a thick ice cover, the average thickness of which is about 2000 m. Due to the thickness of the ice, Antarctica turned out to be the highest continent on Earth. The shores of the mainland are mostly ice cliffs of several tens of meters. Due to its geographical location and ice shell, Antarctica is the world's pole of cold.
Discovery of Antarctica
First research. Antarctica was discovered much later than other continents. Even ancient scientists expressed the idea of the existence of a continent in the high latitudes of the southern hemisphere. But finally there was a question about the existence of a sixth continent. resolved much later. In the second half of the 18th century. An English expedition headed by the famous English navigator James Cook set off in search of the Southern continent.
J. Cook crossed the Antarctic Circle more than once, but was never able to break through the ice to the mainland. He came to the gloomy conclusion that "the lands that may be in the south will never be explored... this country is doomed by nature to eternal cold." The results of J. Cook's expedition cooled for a long time the desire to embark on risky voyages in search of the mainland.
Only in 1819 was the first Russian Antarctic expedition organized on the ships “Vostok” and “Mirny” under the command of Thaddeus Faddeevich Bellingshausen and Mikhail Petrovich Lazarev, which circumnavigated the unknown continent and came close to its shores, discovering many islands. 1820, when the expedition first approached the shores of Antarctica, is considered to be the year of its discovery, which marked the beginning of an intensive study of the coastal zone of the Southern continent.
On December 14, 1911, the Norwegian Roald Amundsen, and a month later - on January 18, 1912 - the Englishman Robert Scott reached the South Pole. This was the greatest geographical discovery. Scientists received the first information about the interior of the continent. But they came at a high price. R. Scott's group died on the way back, not reaching just a few kilometers to the warehouse where there were food and fuel.
In November 1912, a rescue squad found a tent with frozen bodies in it. Next to the tent stood a sleigh with a geological collection weighing more than two pounds.
Modern exploration of Antarctica
Research of Antarctica by Soviet scientists. In the first half of the 20th century. The USA, Great Britain, Australia, Norway and other countries organized special expeditions to study Antarctica. Each country pursued its own goals and acted alone. Research was carried out mainly on the coast, while the interior of the mainland remained little known.
Only in connection with the International Geophysical Year (IGY, 1957 - 1958) did twelve countries of the world decide to jointly study the continent and exchange information. The Soviet Union took one of the leading places in this work. Soviet expeditions were organized at a high scientific and technical level. To carry them out, rich practical experience in the study and development of the Arctic was used. Despite the fact that the Soviet Union had no previous scientific stations or experience working in Antarctica at the beginning of the IGY, our researchers boldly moved deeper into the continent.
In difficult climatic conditions, in a short period of time, they built several scientific stations (Mirny, Pionerskaya, Vostok, etc.) not only on the coasts, but also in the internal hard-to-reach parts of Antarctica, where no human had ever set foot (Pole of Inaccessibility). The main and largest at this time is Molodezhnaya station. The Antarctic Aerometeorological Center is located here.
For more than three decades, Soviet specialists have been successfully working, a large amount of scientific material has been collected, many works have been written, and the first Soviet Atlas of Antarctica has been created. It can be used to obtain information about all components of Antarctic nature. Hundreds of names of Russian and Soviet explorers are immortalized on the map of Antarctica.
Antarctica differs from other continents not only in the absence of a permanent population, but also in its legal status. It does not belong to any state. According to an international agreement, any military activities, weapons testing and nuclear explosions are prohibited on its territory. The law enshrines the protection of Antarctic nature.
It is no coincidence that Antarctica is called the continent of science and peace. Thanks to well-organized international cooperation and the hard work of scientists, many of Antarctica's mysteries have now ceased to exist. by Abramenko
Ice sheet
How much ice is there in Antarctica? What is under the thick ice sheet? Just 30 - 35 years ago these questions could not be answered with confidence. Scientists have found that the Antarctic Platform lies at the heart of most of the continent - in its eastern half. Almost the entire continent is covered by an ice sheet, the average thickness of which is about 2000 m, and in the eastern part the maximum thickness reaches 4500 m.
The average height of the continent, taking into account the ice cover, is 2040 m. This is almost 3 times higher than the average height of other continents. The ice cover of Antarctica contains about 80% of all fresh water on Earth. The ice sheet resembles a dome, raised in the central part of the continent and lowered towards the coast, gradually spreading towards the periphery.
Subglacial relief
Modern research methods have made it possible to obtain a clear picture of the subglacial topography of the continent. About 1/3 of its surface lies below ocean level. At the same time, mountain ranges and massifs were discovered under the glacial shell. From the Weddell Sea to the Ross Sea, along the fault zone, stretch the Transantarctic Mountains, which separate West Antarctica from East Antarctica, which differ greatly in relief.
West Antarctica is characterized by great dissection. Along the Antarctic Peninsula and the western edge of the continent stretch mountains that serve as a continuation of the Andes of South America. Here is the highest mountain range of the continent (5140 m), the deepest depression (-2555 m). Most of the mountains are covered with a continental glacier, and only in some places their highest peaks rise bizarrely above the icy desert. Lavas rising along fault lines play a significant role in the structure of mountains.
In East Antarctica, under a continuous cover of ice, flat areas of the surface alternate with mountain ranges 3000 - 4000 m high. They are composed of ancient sediments, similar to the rocks of other continents that were part of the ancient continent of Gondwana.
The features of the glacial and subglacial relief of East Antarctica are clearly visible on the surface profile of Antarctica compiled by Soviet polar explorers during the expedition of a sledge-caterpillar train along the route Mirny - Pole of Inaccessibility, Mirny - South Pole. At the edge of the mainland, on one of the coastal islands of the Ross Sea, the active volcano Erebus rises - a witness to active mountain-building processes in this area.
Almost all of Antarctica is located in the Antarctic climate zone. This is the coldest continent on Earth. The climate is especially harsh in the interior regions of the continent. The average daily temperature there, even in summer, does not rise above - 30 ° C, and in winter it is lower - 70 ° C. Antarctica is called the “refrigerator” of the Earth. Due to its influence, the southern hemisphere is much colder than the northern. Soviet polar explorers at the Vostok station recorded the lowest temperature on Earth (-89.2°C). That is why the Vostok station is called the Earth's Pole of Cold. At such a low temperature, the metal becomes brittle and breaks like glass on impact, while kerosene thickens and can be cut.
There have been cases of frostbite in people's lungs and corneas due to severe frosts. Therefore, to work in such conditions you have to use special clothing. Antarctic air is amazingly transparent and dry.
In summer, Antarctica receives more solar heat than the equatorial region of the Earth. But 90% of this heat is reflected by snow and ice. In addition, summer is very short. On the coast of the mainland it is much warmer; in summer the air temperature rises to 0° C, and in winter there are moderate frosts. In areas where there is no ice cover in summer, rocks absorb up to 85% of solar heat, heat themselves, and heat the surrounding air. Oases are formed here. In the oases, the temperature in summer is much higher than above the surrounding glaciers. They are real centers of warmth.
The southern parts of the three oceans adjacent to Antarctica are located in the subantarctic belt. Temperatures here are higher than above the mainland. Due to the large difference in temperature and atmospheric pressure over the interior of Antarctica and over the oceans washing the continent, constant winds from the mainland blow in the coastal strip. Toward the coast they intensify and sometimes reach hurricane force. These winds blow huge amounts of snow from the mainland into the ocean.
In winter, the seas are covered with solid ice. In summer, the edge of solid ice retreats almost to the very shore. Continental ice sliding into the water breaks off and forms huge icebergs. Currents carry them far out into the ocean.
The distribution of precipitation, as well as temperatures, has a well-defined zonality. The central parts of the continent receive from 40 - 50 to 100 mm per year, like the Sahara.
Flora and fauna
Most of Antarctica is devoid of vegetation and animal life. This is the Antarctic desert. Modern organisms of Antarctica are represented by mosses, lichens, microscopic fungi and algae, etc. Plants grow in areas free of ice cover, even near the pole. The oases of Antarctica can be considered as centers of life in an icy desert. The lakes of the oases are rich in a variety of algae. Bacteria were found in the snow near the Pole of Cold.
The fauna is connected with the oceans washing the continent. The waters of Antarctica are rich in plankton, which is a source of food for whales, seals, fish and birds. Several species of cetaceans are found here, among them the largest animals on our planet - blue whales, as well as sperm whales and killer whales. Pinnipeds are widespread.
There are several types of penguins. The most common is the small Adelie penguin. Emperor penguins are especially beautiful, weighing up to 50 kg and more than a meter high. They hatch their offspring in the harsh winter without making nests, and hold the eggs in their paws, pressing them against the down of their warm belly. Antarctic and snow petrels nest high in the mountains. On the coast in summer you can see cormorants and skuas. Skuas are very peaceful, they accompany polar explorers; Eating edible waste, they act as orderlies.
Practical and scientific significance of modern Antarctic research. Research in Antarctica takes place under extremely difficult conditions. What explains the enormous interest in studying the icy continent?
A variety of minerals were discovered in its depths: coal, iron ore, non-ferrous metals. Traces of oil and natural gas were found. Scientists suggest that there is gold, diamonds, and uranium there. The ocean waters of Antarctica are rich in large marine animals, fish, and crustaceans. Whales, especially the largest, the blue whale, have been greatly exterminated and have been protected since 1967. Antarctica contains huge reserves of fresh water. There are now projects to tow icebergs to countries suffering from a lack of it.
The study of Antarctica has not only practical, but also scientific significance. The processes occurring in Antarctica inevitably affect the nature of the surface of the entire Earth. For example, changes in the level of the World Ocean largely depend on the behavior of ice (ice accumulation, changes in movement speed, melting). The atmosphere over Antarctica influences the movements of air masses throughout the planet.
The ice cover, which arose 20 million years ago, contains rich information about secular climate fluctuations, as well as about the history of the development of the Earth's natural complexes.
Antarctica (the opposite of the Arctic) is a continent located in the very south of the Earth; the center of Antarctica approximately coincides with the southern geographic pole. Antarctica is washed by the waters of the Southern Ocean (in Russia, this ocean is often considered to be the southern parts of the Indian, Pacific and Atlantic oceans). The continent's area is 12.4 million km² (another 1.6 million km² are ice shelves). Antarctica was discovered on January 16 (January 28), 1820 by a Russian expedition led by Thaddeus Bellingshausen and Mikhail Lazarev, who approached it at 69°21′ S. w. 2°14′ W d. (G) (region of the modern Bellingshausen ice shelf). The first to set foot on the continental part were on January 24, 1895, the captain of the Norwegian ship "Antarctic" Christensen and natural science teacher Carlsten Borchgrevink.
Antarctica is the coldest of all continents. In terms of territory, Antarctica is far from the last place among other parts of the world. Its area is about 1,400 million km2, which is almost twice the area of Australia and one and a half times the area of Europe. With its outlines, Antarctica slightly resembles the Arctic Ocean. Antarctica is very different from all other continents. A thick layer of ice covers almost the entire continent. Thanks to colossal glaciation, Antarctica is the highest continent on earth, its average height exceeds 2000 m, over 1/4 of its surface is at an altitude of more than 3000 m. Antarctica is the only continent on which there is not a single permanent river, and yet on It contains 62% of the earth's fresh water in the form of ice.
Fig.1. Antarctica (satellite image)
If the ice sheet of this continent began to melt, it could feed the rivers of our planet, with the water content that they have, for more than 500 years, and the level of the World Ocean, from the water entering it, would rise by more than 60 meters. The magnitude of the glaciation can be judged if only because this ice is enough to cover the entire globe with a layer about 50 meters thick.
If you remove all the ice cover from Antarctica, it will be similar to all other continents with complex terrain - mountains, plains and deep depressions. An important difference from other continents is the complete absence of state borders and permanent population. Antarctica does not belong to any state; no one lives there permanently. Antarctica is a continent of peace and cooperation. Any military preparations are prohibited within its boundaries. No country can claim it as their land. This is legally enshrined in an international treaty that was signed on December 1, 1959. and entered into force on June 23, 1961, Antarctica does not belong to any state. Only scientific activities are permitted.
The placement of military facilities, as well as the entry of warships and armed vessels south of 60 degrees latitude are prohibited.
In the 80s of the 20th 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. Currently, 28 states (with voting rights) and dozens of observer countries are parties to the treaty. However, the existence of a treaty does not mean that the states that joined it renounced their territorial claims to the continent and the surrounding area. On the contrary, the territorial claims of some countries are enormous. For example, Norway claims territory that is ten times larger than its own (including the island of Peter I, discovered by the Bellingshausen-Lazarev expedition). Great Britain declared huge territories as its own.
Australia considers almost half of Antarctica its own, into which, however, the “French” Adélie Land is wedged. New Zealand also made territorial claims. Great Britain, Chile and Argentina claim almost the same territory, including the Antarctic Peninsula and the South Shetland Islands. The United States and Russia took a special position, declaring that, in principle, they can put forward their territorial claims in Antarctica, although they have not yet done so. At the same time, both states do not recognize the claims of other countries.
History of the study of the continent
James Cook was the first to suggest existence in the cold south of the continent. However, very difficult ice conditions did not allow it to reach the shores of the continent. This was done on January 16 (January 28), 1820, by a Russian expedition led by Thaddeus Bellingshausen and Mikhail Lazarev. After this, the study of the coast of the continent and its interior began. Numerous studies were carried out 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 began 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, Robert Scott's party arrived at the cherished point and died on the way back.
Fig.2. Ice of Antarctica
From the middle of the 20th century, the study of Antarctica began on an industrial basis. On the continent, various countries are creating numerous permanent bases that conduct meteorological, glaciological and geological research all year round. In total, there are about 45 year-round scientific stations in Antarctica. Currently, Russia has five operating stations and one field base in Antarctica: Mirny, Vostok, Novolazarevskaya, Progress, Bellingshausen, Druzhnaya-4 (base). Three stations are in a mothballed state: Molodezhnaya, Russkaya, Leningradskaya. The rest no longer exist: Pionerskaya, Komsomolskaya, Sovetskaya, Vostok-1, Lazarev, Pole of Inaccessibility.
From 1957 to 1959, the International Geophysical Year took place, 65 countries agreed to send expeditions to Antarctica, build scientific stations and conduct various studies. More than 60 research stations have been built in Antarctica. Scientists from many countries around the world work there. In 1959, an international treaty on Antarctica was signed, according to which it is prohibited to build industrial and military facilities there. The entire continent is available to scientists for research, which is why Antarctica is called the continent of scientists.
The first Soviet expedition to Antarctica was led by Hero of the Soviet Union M. M. Somov. At the beginning of January 1956, the flagship ship of the expedition, the diesel-electric ship Ob, under the command of Captain I. A. Man, approached the Helen Glacier in thick fog and passed through a narrow passage between icebergs east of the mouth of the glacier into Depot Bay of the Davis Sea. The search began for a site to build a research station. A suitable location was found in the Haswell Island area.
In mid-February 1956, the grand opening of the first Soviet observatory on the shores of Antarctica took place. The observatory was named “Mirny” - in honor of one of the ships of the First Russian Antarctic Expedition of Belingshausen - Lazarev. From the first days of the existence of the Soviet base, scientific research began in all planned areas. The coast where the expedition settled was called the Coast of Truth.
Scientists have proven that Antarctica was previously a green city. And under the ice there are mountains, valleys, plains, former river beds, bowls of former lakes. Millions of years ago there was no eternal winter on this earth. Here the forests rustled warmly and greenly, tall grasses swayed under the warm winds, animals gathered to drink on the banks of rivers and lakes, birds fluttered in the sky. Scientists suggest that Antarctica was once part of a giant continent called Gondwana. A few months later, the expedition undertook a sleigh-caterpillar voyage into the depths of the “white spot” of East Antarctica and organized the inland station “Pionerskaya” 370 km from the coast, at an altitude of 2700 m above sea level. On this slope of the glacier dome, even in the best weather, a smoky wind blows, sweeping the snow.
Fig.3. Vostok station (Russia)
The second Soviet Antarctic expedition, led by A.F. Treshnikov, moved even further into the continent. Researchers came to the South Geomagnetic Pole and, at a distance of 1400 km from the coast, at an altitude of 3500 m above sea level, built a permanent scientific station “Vostok”. Everything necessary for the life and work of polar explorers is delivered from their homeland by several ships; in addition, winterers have tractors, tractors, airplanes, and helicopters.
Thanks to the light AN-2 aircraft and the MI-4 helicopter, which helped quickly get to any point on the coast, geologists studied in a short time dozens of rocky mountains - nunataks protruding from the ice sheet, surveyed the Mirny rocks and the Bangera Hills oasis and its surroundings. Biologists flew over many coastal islands by plane, describing the flora and fauna of these areas. The vegetation here is lichens, mosses and blue-green algae. Antarctica lacks land mammals, winged insects and freshwater fish. More than 100 thousand penguins nest near Mirny, many petrels, skuas, and seals and leopard seals live in the waters.
The third Soviet Antarctic expedition worked during the International Geophysical Year. By this time, two more stations had been built - “Komsomolskaya” and in an area of relative inaccessibility - “Sovetskaya”. 24-hour atmospheric monitoring was organized at the stations. Our planet's Pole of Cold was discovered. It is located near the Vostok station. Here the average monthly temperature in August is 71 C and the minimum temperature is 88.3 C. At such temperatures, the metal becomes brittle, diesel fuel turns into a dough-like mass, kerosene does not flare up, even if a burning torch is lowered into it. During the work of the Fourth Soviet Antarctic Expedition, a new station “Lazarev” was still operating on the shore of Queen Maud Land, but later it was rewritten 80 km inland and called “Novolazarevskaya”. The participants of this expedition made a sleigh-caterpillar trip from the Vostok station to the South Geographic Pole. In October 1958, Soviet pilots on an IL-12 plane made a transcontinental flight from Mirny, through the South Pole, to the American McMurdo base, located near Ross Island. This was the first Soviet aircraft over the South Pole.
Fig.4. Aerial view of Beardmore Glacier in 1956
At the end of 1959, during the Fourth Soviet Antarctic Expedition, researchers made an outstanding trip on all-terrain vehicles. This hike took place in the most difficult sector of Antarctica along the route Mirny-Komsomolskaya-East-South Pole. On December 26, 1959, a Soviet train of all-terrain vehicles arrived at the Amundsen - Scott station, where the Soviet polar explorers were warmly greeted by the Americans. The participants of the trip made a traditional trip around the world around the earth's axis, which took only a few minutes. During this trip, our scientists measured the thickness of the ice sheet using the seismoacoustic method. It turned out that under the Vostok station the thickness of the glacier is 3700 m, and at the South Pole - 2810 m; from the Pionerskaya station to the South Pole there is a vast subglacial plain lying at sea level. It was called the Schmidt Plain - in honor of the famous Soviet polar explorer - Otto Yulievich Schmidt. The results of research by scientists from different countries around the world were combined into one common system. Based on them, maps of the subglacial relief and thickness of the Antarctic ice sheet were compiled.
International cooperation allows us to unite the work of scientists and contributes to a better study of the nature of Antarctica. At the American Amundsen-Scott station, for example, Soviet scientists often visit and work, and at the Soviet Vostok station, located at the South Geomagnetic Pole, American scientists spend the winter and work. Now reaching the South Pole is a relatively simple matter. American researchers are always here, dozens of planes fly here every year, correspondents, congressmen and even tourists fly here.
Soviet expeditions go to Antarctica every year. New stations were built - “Molodezhnaya”, “Bellingshausen” in West Antarctica, “Leningradskaya” on Victoria Land, not far from the Ross Sea. The richest scientific materials have been collected. For example, seismic observations made it possible to register earthquakes on the Antarctic continent, albeit very weak ones.
Geological structureGeologists have established that the depths of Antarctica contain significant mineral resources - iron ores, coal, traces of copper, nickel, lead, zinc, molybdenum ores have been found, rock crystal, mica, and graphite have been found.
The Transantarctic Mountains, crossing almost the entire continent, divide Antarctica into two parts - West Antarctica and East Antarctica - having different origins and geological structures. In the east there is a high (highest elevation of the ice surface ~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 altitude exceeds 4000 m; the highest point of the continent - 4892 m above sea level - the Vinson Massif of the Sentinel Ridge. In West Antarctica there is also the deepest depression of the continent - the Bentley Trench, probably of rift origin. The depth of the ice-filled Bentley Trench reaches 2555 m below sea level.
West Antarctica is a younger and more dissected region, formed over the last 500 million years by the addition of small continental microplate fragments to the Antarctic plate. The largest are the Ellsworth Mountains, the Antarctic Peninsula and Mary Bird Land. The collision of these microplates with the Antarctic plate led to the formation of the mountains of West Antarctica.
Ice sheetThe Antarctic Ice Sheet is the largest ice sheet on the planet and is approximately 10 times larger in area than the closest one, the Greenland Ice Sheet. It contains ~30 million km³ of ice, that is, 90% of all land ice. The ice sheet is dome-shaped, with the surface increasing in steepness towards the coast, where it becomes ice shelves or 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 is the coast continent; the ice breaks off in the form of icebergs. The annual volume of ablation is estimated at 2500 km³.
Fig.5. Ice sheet of Antarctica
A special feature of Antarctica is the large area of ice shelves, low (blue) areas of West Antarctica), accounting for ~10% of the area above sea level; these glaciers are sources of icebergs of record sizes, significantly exceeding the size of the icebergs of the fiord glaciers of Greenland; for example, in 2000, the largest currently known iceberg (2005), B-15, with an area of over 10,000 km², broke off from the Ross Ice Shelf. In summer (winter in the southern hemisphere), the area of the Antarctic ice sheet increases by 3-4 million km² due to the growth of ice shelves, primarily around the Antarctic Peninsula and in the Ross Sea.
The modern ice sheet of Antarctica formed several million years ago, which was apparently facilitated by the rupture of the bridge connecting South America and the Antarctic Peninsula, which led, in turn, to the formation of the Antarctic circumpolar current (Western Wind Current) and the isolation of Antarctic waters from the World Ocean - these waters make up the so-called Southern Ocean.
East Antarctica is an ancient Precambrian continental platform (craton) similar to those of India, Brazil, Africa and Australia. All these cratons were formed during the breakup of the supercontinent Gondwana. The age of the crystalline basement rocks is 2.5-2.8 billion years, the oldest rocks of the Enderby Land are more than 3 billion years old.
Fig.6. Lemaire channel
The foundation is covered by a younger sedimentary cover, formed 350-190 million years ago, mainly of marine origin. In layers with an age of 320-280 million years, there are glacial deposits, but younger ones contain fossil remains of plants and animals, including ichthyosaurs and dinosaurs, which indicates a strong difference in the climate of that time from the modern one. Findings of heat-loving reptiles and fern flora were made by the first explorers of Antarctica, and served as one of the strongest evidence of large-scale horizontal plate movements, confirming the concept of plate tectonics.
Seismic activity. VolcanismAntarctica is a tectonically calm continent with little 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 volcanoes, have erupted in the last 200 years. The most active volcano in Antarctica is Erebus. It is called “the volcano guarding the path to the South Pole.”
Antarctica was discovered later than other continents, since it is remote from all centers of human civilization. Even in ancient times, people assumed the existence of a large area of land in the south, however, for many centuries travel here remained almost impossible. Only at the end of the Middle Ages, with the beginning of the Age of Great Geographical Discovery, the level of European navigation finally reached such a development that it became possible to cross the ocean on ships and discover new continents. The boundaries of “terra incognito” were constantly shrinking, however, since the time of Columbus’s voyage, for almost 200 years no one had reached the southern polar seas of the planet. The era of Spanish and Portuguese dominance at sea had already passed, British and Dutch ships began to sail the oceans, but the legends about “terra australis” or the southern land still remained legends. And only with the travels of James Cook (photo) in 1768 - 1771 it was proven that, obviously, this southern continent is the continent discovered in 1606 by Billem Janszoon, and later called Australia. James Cook's second expedition of 1772 - 1775 finally dissuaded researchers that there might be some other lands in the south that could be discovered, since Cook's expedition was stopped by the ice surrounding Antarctica. His ships circled the entire continent, but were never able to reach the shores, although they crossed the Antarctic Circle several times. Cook wrote in his diaries that “the lands that may be in the south will never be explored ... this country is doomed by nature to eternal cold.” After the voyage of James Cook, for several decades no further attempts were made to explore these territories of eternal ice, although in the period from 1800 to 1810 the British managed to discover several more islands in the subantarctic strip of the Southern Ocean. But it was only in 1819 that the first Russian expedition was organized to explore the Antarctic. On the ships “Vostok” and “Mirny” under the leadership of Thaddey Faddeevich Bellingshausen and Mikhail Petrovich Lazarev. During the expedition, ships approached the shores of the icy continent nine times, four times at a distance of less than 3–15 km. For the first time, they characterized large water areas adjacent to the mainland, described and classified Antarctic ice, and also compiled a description of the Antarctic climate, and 28 geographical names were applied to its map, including the Coast of Alexander I, discovered on January 15, 1821. As F.F. wrote down that day. Bellingshausen: “I call this discovery a shore because the distance of the other end to the south has disappeared beyond the limits of our vision... A sudden change of color on the surface of the sea gives the idea that the shore is extensive. » In the 60s. In the 20th century, it was proven that the Earth discovered by Russian navigators is not an island, but is connected to Antarctica by the George VI ice shelf.
From this time on, active exploration of Antarctic territories began. In the summer of 1822 - 1823, the Scottish St. John's wort Wedell, under exceptionally favorable weather conditions, walked from the island of South Georgia to 74°15'S. and at the end of February 1823, he sailed freely on the high seas, later named after him the Wedell Sea, the southernmost sea of the Atlantic. Then, in the 20s, the results of his voyage were perceived as proof that there was no vast land in the south, but upon further study in the 30s-40s of the 19th century, this hypothesis was completely refuted. In 1838 - 1842, an American government expedition led by Charles Wilkes traveled along the coast of Antarctica, discovering a significant part of its coastline. His expedition covered a long distance - about 2800 km near the coast of Antarctica, famous for its severe storms (later D. Mawson called it the “Abode of Snow Storms”). However, in the middle of the 19th century, the existence of the Antarctic continent was still in question. The journey of the English expedition of James Ross especially greatly shook faith in its reality. On two ships, the Erebus and the Terror, at the beginning of October 1840, he set sail for the southern seas. During the expedition, he reached the 78th parallel, setting a record for sailing in southern latitudes. Here, on the island he called “Vysoky” (now Ross Island), his expedition discovered two twin volcanoes, named after ships. Here, in the south of the sea, which received the name of Ross himself, the navigator discovered a land named after the Queen of England - Victoria Land. Ross correctly calculated that on this Earth, 300 km from the coast, the southern magnetic pole of the planet is located, however, he incorrectly decided that Victoria Land was a large island, and not part of the whole continent. During these years, Great Britain increasingly began to lay claim to ownership of the southern “islands.”
After the voyage of James Clark Ross, research in the southern waters stopped for 30 years, and only in 1874 - 1875 the English oceanographic expedition of Charles Whiteville Thompson set off here again on the steam corvette Challenger. Naturalist John Murray, who was present, having studied the collected samples and analyzed the discoveries of his predecessors, came to the firm conclusion that a large part of the land is located in the south of the planet. He was the first to map the coastline of Antarctica. On January 24, 1895, the Norwegian fishing steamer Antarctic landed on the shores of Victoria Land. Here, the young biologist Carsten Borchgrevink, who quit teaching at the university and got a job as a simple sailor on this ship to explore the Antarctic, discovered several species of mosses and even three species of flowering plants in areas not occupied by ice, proving that even in Antarctica there is life. At the turn of the century, the development of the interior regions of the ice continent began.
At the beginning of the 20th century, expeditions to the polar mountain ranges and glaciers of the mainland began one after another. Preparations begin to reach the planet's South Pole. In 1909, the Norwegian Roald Amundsen is preparing for this very difficult and dangerous crossing of the icy continent. On January 14, 1911, the Norwegians landed on the coast of Antarctica in Whale Bay. Together with them, an English expedition led by Robert Scott set off to conquer the pole, arriving in Antarctica a few days earlier - on January 3. Amundsen's proposed route was 100 kilometers shorter than Scott's, but it covered more difficult terrain. But Amundsen calculated all stages of the campaign with amazing accuracy. Between 80° and 85°, every degree he set up warehouses with food and fuel, and to make them easy to find, he installed high milestones with flags. Amundsen's trek began on October 20, 1911, with four companions on a dog-drawn sleigh. Beyond the 85th parallel, a difficult climb began from the Ross Ice Shelf to the ridge, which Amundsen named the Queen Maud Ridge in honor of the Norwegian queen (later it was proven that this ridge belongs to the Transantarctic Mountains). When some of the provisions had already run out, Amundsen ordered the killing of the extra dogs in order to feed them with the meat of the remaining animals, however, the travelers themselves ate this meat, because provisions were running out. The Norwegian expedition reached the South Pole on December 15, 1911. They pitched a tent on a high plateau, 2800 meters high, and raised the Norwegian flag there. Roald Amundsen and his companions became the first people to conquer the South Pole. On December 17 they turned north. They had to kill one dog every three days, so people and animals ate fresh meat until they reached the 85th parallel, where the first warehouse they left was located. Having traveled 2,800 km round trip, they returned to Whale Bay on January 26, 1912 after a 99-day ice voyage.
At this time, Robert Scott planned to reach the Pole on a motor sleigh, Indian ponies and dogs. They set off on November 2, 1911. However, the technology failed Scott, the motor sled soon had to be abandoned, and beyond the 83rd parallel the ponies had to be killed when there was nothing to feed them. At 84° the dog sleds were sent back, and the British themselves pulled the heavily loaded sleighs. Beyond the 85th parallel, Scott ordered four people to return, and at 87°30' three more. Only five people went further: Robert Scott, doctor Edward Wilson, officers Lawrence Oates and Henry Bowers, and non-commissioned officer Edgar Evans (Pictured). The last 250 km were especially difficult for them. The sleigh had to be dragged through dry, loose snow; per hour they moved no more than 2 km, and in a day they moved less than 10 km. When there were several miles left to the Pole, Scott wrote in his diary: “... we saw a black dot ahead... [which turned out to be] a black flag tied to a sleigh runner. The remains of a camp were visible nearby... The Norwegians were ahead of us. They were the first to reach the pole. Terrible disappointment! On the road from their base to the Pole, the British set up ten intermediate warehouses for provisions and fuel. On the way back, their immediate goal was to quickly get to the next warehouse in order to replenish fuel supplies. However, the travelers' strength quickly faded. Soon the youngest of them, Evans, began to feel signs of mental illness, he fell behind, fell until he was completely exhausted. On February 17 he passed away. The further path turned out to be even more difficult. Scott's team increasingly lost their way. At the end of February, when “fuel became terribly low,” severe frosts began. Scott's notes showed how their will to live disappeared and their despair grew. But they didn’t give up until the very end and dragged behind them about 15 kilograms of the most valuable rock samples collected on the way to the Pole. Friday March 16th or Saturday March 17th, Scott wrote in his diary: “I lost track of the numbers, but it seems to be the last one. Our life is a pure tragedy. Ots said: “I’ll go for a walk. Maybe I won’t be back soon.” He went into a snowstorm, and we didn’t see him anymore... we knew that... Ots was going to his death, and we tried to dissuade him, but... we realized that he was acting like a noble man...” March 29: “From the 21st a continuous storm raged... On the 20th we had enough fuel for two cups of tea each and enough dry food for two days. Every day we were ready to go... but there was no way to leave the tent - the snow was blowing and swirling. I don’t think we can hope for anything else now...” Robert Scott's last entry: "For God's sake, do not abandon our loved ones." The search party found their snow-covered tent only in the spring - November 12, 1912. All the travelers of Scott's expedition died, he himself died last, throwing away the lapels of his sleeping bag and unbuttoning his jacket. They were buried in this place. On the memorial cross installed in the ice in memory of the expedition, an epitaph was carved: “To strive, to seek, to find, and not to yield.” The whole of Great Britain was deeply affected by the news of the death of its heroes. It is worth saying that Scott’s last request found a response in the hearts of the British and was fulfilled. A significant amount collected throughout the country provided a comfortable existence for the relatives of the deceased travelers.
After the conquest of the South Pole by Amundsen and Scott, Antarctic exploration continued with renewed vigor. In December 1911, Douglas Mawson made his first expedition. For wintering, his expedition chose Adélie Land, which, as it turned out, was a place with the harshest climate on Earth. Often the average daily winds here reached a speed of 44 m/s. Mawson had to observe winds of 90 m/s, when the speed of a destructive hurricane was only 30 m/s. Added to all this was the highest amount of precipitation in Antarctica - 1600 mm per year. The campaign of 1912–1913 almost became fatal for Mawson himself, his entire team died, and he himself returned to base only five months later. However, during the expedition, the discoveries of Charles Wilkes were confirmed, vast territories were explored, and the description of the information collected amounted to 22 volumes. In the 20s of the 20th century, flights over Antarctica began, which made it possible to explore the mountains and lands in the depths of the continent. Among the researchers of this time, it is necessary to mention the American pilot Richard Byrd, the Norwegian captain Nils Larsen, and the American engineer Lincoln Ellsworth.
The first Soviet Antarctic scientific expedition, led by the experienced polar explorer and oceanographer Mikhail Mikhailovich Somov, landed on the coast of the Davis Sea on January 6, 1956. Nearby, with the help of the crews of two diesel-electric ships “Ob” and “Lena,” the village of Mirny was built. Antarctic sector between 80° and 105° East. was not chosen by chance. The coast of the mainland was mapped very roughly; during the work of Soviet researchers, many new islands, bays, capes and glaciers were discovered. In addition to the base in the village of Mirny, by the end of 1956, two more stations appeared: Pionerskaya and Oasis station.
There are currently 37 stations operating in Antarctica. Argentina, which has 6 stations here, is actively developing the mainland. after the collapse of the USSR and the economic difficulties that arose, it was forced to freeze some of them. Now there are 5 Russian stations on the mainland: Bellingshausen (62°12'S 58°56'W), Vostok (78°27'S 106°52'E. ), "Mirny" (66°33'S 93°01'E), "Novolazarevskaya" (70°46'S 11°50'E), "Progress" ( 69°23'S 76°23'E) – (Data from the Russian Antarctic Expedition: //www.aari.aq/default_en.html). , Australia and Chile each have 3 stations on the mainland. Great Britain and China – two stations each. Also have one station each: Norway, France, New Zealand, Japan, Brazil, Uruguay, South Korea, South Africa, India, Poland, Ukraine. There is also one joint station between France and Italy.
Since 1961, there has been an agreement signed by all leading countries, according to which territories south of 60° S. are demilitarized and free of nuclear weapons. Also, no country in the world has the right to claim these territories. It provides for freedom of scientific research and encourages international cooperation to ensure that Antarctica is used for the benefit of all mankind.