According to a number of foreign researchers, the situation in Antarctica has become so threatening that it is time to ring all the bells: the data received from satellites irrefutably testify to the catastrophic melting of ice in the territory of West Antarctica. If this continues, glaciologists are convinced, in the near future these glaciers will disappear altogether.
Some of them are shrinking their area at a rate of one to two kilometers per year. But in general, according to measurements received from the CryoSat satellite of the European Space Agency, the ice cover of the Sixth Continent is losing weight by two centimeters every year. At the same time, according to the Air Force, Antarctica is losing about 160 billion ice a year - now the rate of ice melting is already twice as high as four years ago. NASA experts called the Amundsen Sea area the most vulnerable point, where in the six largest glaciers the melting process can already slow down.
The influential Western journal Earth and Planetary Science Letters has published a study that proves that as a result of the melting of Antarctica, deformation occurs earth's crust at a depth of 400 km. “Despite the fact that the Antarctic ice sheet is growing at a rate of 15 mm per year,” they explain, “in general, deep below the ice shelves, there is active melting due to global warming and changes in chemical composition the earth's crust in the Antarctic region. This process entered a critical phase in the late 1990s. And then there's the ozone hole, which also has a bad effect on the Antarctic climate.
How does this threaten us? As a result, the level of the world's oceans can rise by 1.2 meters or even more in a short time. Strong evaporation and a huge amount of water condensation will give rise to powerful typhoons, hurricanes, tornadoes and other natural disasters, many land areas will be flooded. Mankind cannot change the situation. In short, save who can!
"AiF" decided to interview Russian scientists: when exactly will the world be covered by a wave? According to them, it's not so bad. “If a significant rise in the level of the world ocean does occur, then it will not happen tomorrow or even the day after tomorrow,” AiF explained. Alexander Nakhutin, Deputy Director of the Institute for Global Climate and Ecology of Roshydromet and the Russian Academy of Sciences. - The melting of the Antarctic and Greenland glaciers is a very inertial process, slow even by geological standards. Its consequences, at best, will only be seen by our descendants. And then, if the glaciers melt completely. And it will take not a year or two, but a hundred years or more.
There is also a more positive version. The “global” melting of glaciers has nothing to do with the whole of Antarctica, says Nikolai Osokin, Candidate of Geographical Sciences, Deputy Head of the Department of Glaciology at the Institute of Geography of the Russian Academy of Sciences. — Perhaps the melting of six glaciers in the Amundsen Sea is really irreversible, and they will not recover. Well, no big deal! West Antarctica, the smallest part of the mainland last years melted really noticeably. However, in general, the process of active melting of glaciers in Antarctica over the past few years, on the contrary, has slowed down. There is a lot of evidence for this. In the same West Antarctica, for example, the Russian station "Bellingshausen" is located. According to our observations, there is an improvement in the nutrition of glaciers in this area - more snow falls than melts.
Turns out it's not time to ring the bells yet. “In the atlas of snow and ice resources of the world, released by the Institute of Geography of the Russian Academy of Sciences, there is a map: what would happen if all the glaciers on Earth melted at once. It is very popular,” Osokin laughs. - Many journalists use it as a horror story: look, they say, what kind of universal flood awaits us when the level of the world ocean rises as much as 64 meters ... But this is a purely hypothetical possibility. In the next century and even the millennium, this does not threaten us.”
By the way, as a result of studying the ice core in Antarctica, Russian glaciologists have established an interesting fact. It turns out that over the past 800 thousand years on Earth, cooling and warming regularly replace each other. “As a result of warming, glaciers are retreating, melting, the level of the world ocean is rising. And then it happens reverse process It's getting colder, glaciers are growing, ocean levels are falling. This has happened at least 8 times already. And now we are just at the peak of warming. This means that in the coming centuries, the Earth, and with it, humanity will go to a new ice age. This is normal and is associated with the eternal processes of oscillation of the earth's axis, its inclination, changes in the distance from the Earth to the Sun.
Meanwhile, the situation with ice in the Arctic is much more unambiguous: they are melting an order of magnitude faster and more globally than the Antarctic. “Over the past ten years, there have already been several records for the minimum area sea ice in the Northern Arctic Ocean, - reminds Osokin. “The general trend is towards a decrease in the area of ice in the entire North.”
Can humanity, if it wants to, slow down the general warming or cooling? To what extent does anthropogenic activity influence the melting of ice? “If it does, then most likely to a very small extent,” Osokin believes. “The main reason that glaciers are melting is natural factors.” So we just have to wait, hope and believe. For the best, of course."
What will happen if the glaciers of Antarctica melt?
Antarctica is the least explored continent located in the south of the world. Most of its surface has an ice cover, up to 4.8 km thick. The Antarctic ice sheet contains 90% (!) of all the ice on our planet. It is so heavy that under it the mainland sank almost 500 m. Today, the world is seeing the first signs of global warming in Antarctica: large glaciers collapse, new lakes appear, and the soil loses its ice cover. Let's simulate the situation, what will happen if Antarctica loses its ice.
How will Antarctica itself change?
Today the area of Antarctica is 14,107,000 km². If the glaciers melt, these numbers will drop by a third. The mainland will become almost unrecognizable. Under the ice are numerous mountain ranges and massifs. West Side will definitely become an archipelago, and the eastern one will remain a mainland, although, taking into account the rise of ocean waters, it will not hold such a status for a long time.
On this moment on the Antarctic Peninsula, islands and coastal oases there are many representatives flora: flowers, ferns, lichens, algae, and recently their diversity has been gradually increasing. There are also fungi and some bacteria, and seals and penguins occupy the coast. Already now, on the same Antarctic Peninsula, the appearance of tundra is observed, and scientists are sure that with warming there will be both trees and new representatives of the animal world. By the way, Antarctica holds several records: the lowest recorded temperature on Earth is 89.2 degrees below zero; there is the largest crater on Earth; the strongest and longest winds. Today there is no permanent population in Antarctica. There are only employees of scientific stations, and sometimes tourists visit it. With climate change, the former cold continent may become suitable for permanent human habitation, but now it is difficult to talk about this with certainty - everything will depend on the current climatic situation.
How will the world change due to the melting of glaciers?
Rising water levels in the world's oceans So, scientists have calculated that after the melting of the ice cover, the level of the world's oceans will rise by almost 60 meters. And this is a lot and will be equated to global catastrophe. The coastline will shift significantly, and today's coastal zone of the continents will be under water.
If we talk about Russia, then its central part will not suffer much. In particular, Moscow is located 130 meters above the current sea level, so the flood will not reach it. Such will go under the water big cities like Astrakhan, Arkhangelsk, St. Petersburg, Novgorod and Makhachkala. Crimea will turn into an island - only its mountainous part will rise above the sea. And in the Krasnodar Territory, only Novorossiysk, Anapa and Sochi will be heated. Siberia and the Urals will not be subjected to too much flooding - mostly residents of coastal settlements will have to be relocated.
The Black Sea will grow - in addition to the northern part of the Crimea and Odessa, it will also clean up Istanbul. Signed cities that will be under water The Baltic States, Denmark and Holland will almost completely disappear. In general, European cities such as London, Rome, Venice, Amsterdam and Copenhagen will go under water along with everything cultural heritage, so while there is time, be sure to visit them and upload photos to Instagram, because your grandchildren will most likely not be able to do this anymore. The Americans will also have a hard time, who will definitely be left without Washington, New York, Boston, San Francisco, Los Angeles and many other large coastal cities.
What will happen to North America. Signed cities that will be under water
The climate will already undergo unpleasant changes that will lead to the melting of the ice sheet. According to environmentalists, the ice of Antarctica, Antarctica and those that are on mountain peaks help maintain the temperature balance on the planet, cooling its atmosphere. Without them, this balance will be upset. Large quantity incoming fresh water into the oceans will certainly affect the direction of large ocean currents, which largely determine the climatic conditions in many regions. So it is not yet possible to say with certainty what will become of our weather.
The number of natural disasters will increase significantly. Hurricanes, typhoons and tornadoes will claim thousands of lives. Paradoxically, but due to global warming, some countries will begin to experience a shortage of fresh water. And not only because of the arid climate. The fact is that deposits of snow in the mountains provide vast territories with water, and after it melts, there will be no such benefit anymore.
Economy
All this will greatly affect the economy, even if the process of flooding is gradual. Take the US and China, for example! Whether you like it or not, these countries greatly influence the economic situation around the world. In addition to the problem of displacing tens of millions of people and losing their capital, the states will lose almost a quarter of their manufacturing capacity, which will ultimately hit the global economy. And China will be forced to say goodbye to its huge trading ports, which will reduce the flow of products to the world market at times.
How are things today?
Some scientists reassure us that the observed melting of glaciers is normal, because. somewhere they disappear, and somewhere they are formed, and thus the balance is maintained. Others point out that there are still reasons for concern, and provide convincing evidence.
Not so long ago, British scientists analyzed 50 million satellite images of the Antarctic ice sheets and came to the conclusion that they are melting very rapidly. In particular, the gigantic Totten glacier, comparable in size to the territory of France, causes concern. The researchers noticed that it was washed away by warm salt water, accelerating its decay. According to forecasts, this glacier can raise the level of the World Ocean by as much as 2 meters. It is assumed that the Larsen B glacier will collapse by 2020. And he, by the way, as much as 12,000 years.
According to the BBC, Antarctica loses as much as 160 billion ice a year. And this number is growing rapidly. Scientists say they did not expect such a rapid melting of the southern ice.
The most unpleasant thing is that the process of melting glaciers has an even greater effect on the increase in the greenhouse effect. The fact is that the ice sheets of our planet reflect part of the sunlight. Without this, heat will linger in the Earth's atmosphere in large volumes, thereby raising the average temperature. And the growing area of the World Ocean, whose waters collect heat, will only aggravate the situation. Besides a large number of melt water also adversely affects glaciers. Thus, ice reserves not only in Antarctica, but throughout the globe, are melting faster and faster, which ultimately threatens with big problems.
Conclusion
Opinions of scientists about the melting of the Antarctic ice sheet are very different, but what is known for certain is that man, through his activities, greatly affects the climate. If humanity does not solve the problem of global warming in the next 100 years, then the process will be inevitable.
Many people imagine Antarctica to be a huge continent completely covered with ice. But all this is not so simple. Scientists have found that in Antarctica earlier, about 52 million years ago, palm trees, baobabs, araucaria, macadamia and other types of heat-loving plants grew. Then the mainland had a tropical climate. Today the continent is a polar desert.
Before we dwell on the question of how thick the ice is in Antarctica, we list some Interesting Facts concerning this distant, mysterious and coldest continent of the Earth.
Who owns Antarctica?
Before we proceed directly to the question of how thick the ice is in Antarctica, we should decide who owns this unique little-studied continent.
It doesn't really have any government. Many countries at one time tried to seize ownership of these desert, far from civilization lands, but on December 1, 1959, a convention was signed (entered into force on June 23, 1961), according to which Antarctica does not belong to any state. Currently, 50 states (with the right to vote) and dozens of observer countries are parties to the treaty. However, the existence of an agreement does not mean that the countries that signed the document have renounced their territorial claims to the continent and adjacent space.
Relief
Many imagine Antarctica as an endless icy desert, where, apart from snow and ice, there is absolutely nothing. And to a greater extent this is true, but there are some interesting moments that should be considered. Therefore, we will discuss not only the thickness of ice in Antarctica.
On this mainland there are quite extensive valleys without ice cover, and even sand dunes. There is no snow in such places, not because it is warmer there, on the contrary, the climate is much harsher there than in other regions of the mainland.
The McMurdo Valleys are exposed to terrible katabatic winds that reach speeds of 320 km per hour. They cause a strong evaporation of moisture, which is the reason for the absence of ice and snow. Living conditions here are very similar to those on Mars, so NASA tested the Viking (spacecraft) in the McMurdo Valleys.
Exists in Antarctica and a huge mountain range comparable in size to the Alps. His name is the Gamburtsev Mountains, named after the famous Soviet geophysicist Georgy Gamburtsev. In 1958, his expedition discovered them.
The mountain range is 1300 km long and 200 to 500 km wide. Its highest point reaches 3390 meters. The most interesting thing is that this huge mountain rests under powerful thicknesses (up to 600 meters on average) of ice. There are even areas where the thickness of the ice cover exceeds 4 kilometers.
About the climate
Antarctica has a surprising contrast between the amount of water (70 percent fresh water) and the rather dry climate. This is the driest part of the entire planet Earth.
Even in the most sultry and hot deserts of the whole world, more rain falls than in the arid valleys of the mainland Antarctica. In total, only 10 centimeters of precipitation falls at the South Pole in a year.
Most of the continent is covered eternal ice. What is the thickness of the ice on the mainland of Antarctica, we will find out a little lower.
About the rivers of Antarctica
One of the rivers that carry meltwater in an easterly direction is Onyx. It flows to Lake Vanda, which is located in the arid Wright Valley. Due to such extreme climatic conditions, Onyx carries its waters for only two months a year, during the short Antarctic summer.
The length of the river is 40 kilometers. There are no fish here, but a variety of algae and microorganisms live.
Global warming
Antarctica is the largest piece of land covered with ice. Here, as noted above, 90% of the total mass of ice in the world is concentrated. The average ice thickness in Antarctica is approximately 2133 meters.
If all the ice on Antarctica melts, the sea level could rise by 61 meters. However, at the moment, the average air temperature on the continent is -37 degrees Celsius, so there is no real danger of such a natural disaster yet. In most of the continent, the temperature never rises above zero.
About animals
The fauna of the Antarctic is represented by individual species of invertebrates, birds, and mammals. Currently, at least 70 species of invertebrates have been found in Antarctica, and four species of penguins nest. The remains of several species of dinosaurs have been found on the territory of the polar region.
Polar bears, as you know, do not live in Antarctica, they live in the Arctic. Most of the continent is inhabited by penguins. It is unlikely that these two species of animals will ever meet in natural conditions.
This place is the only one on the entire planet where unique emperor penguins live, which are the tallest and largest among all their relatives. In addition, it is the only species that breeds during the Antarctic winter. Compared to other species, the Adélie penguin breeds in the very south of the mainland.
The mainland is not very rich in land animals, but in coastal waters you can meet killer whales, blue whales and fur seals. An unusual insect also lives here - a wingless midge, the length of which is 1.3 cm. Due to extreme windy conditions, flying insects are completely absent here.
Among the numerous colonies of penguins, there are black springtails jumping like fleas. Antarctica is also the only continent where it is impossible to meet ants.
Area of ice cover around Antarctica
Before we find out what is the greatest thickness of ice in Antarctica, consider the areas of sea ice around Antarctica. They increase in some areas and simultaneously decrease in others. Again, the cause of such changes is the wind.
For example, northern winds drive huge blocks of ice away from the mainland, in connection with which the land partially loses its ice cover. As a result, there is an increase in the mass of ice around Antarctica, and the number of glaciers that form its ice sheet is decreasing.
The total area of the mainland is approximately 14 million square kilometers. In summer, it is surrounded by 2.9 million square meters. km of ice, and in winter this area increases by almost 2.5 times.
subglacial lakes
Although the maximum thickness of ice in Antarctica is impressive, there are underground lakes on this continent, in which, perhaps, life also exists, having evolved completely separately for millions of years.
In total, the presence of more than 140 such reservoirs is known, among which the most famous is Lake. Vostok, located near the Soviet (Russian) station "Vostok", which gave the lake its name. A four-kilometer thickness of ice covers this natural object. Not thanks to the underground geothermal sources located under it. The water temperature in the depths of the reservoir is about +10 °C.
According to scientists, it was the ice massif that served as a natural insulator, which contributed to the preservation of the most unique living organisms that developed and evolved for millions of years completely apart from the rest of the world of the icy desert.
The Antarctic ice sheet is the largest on the planet. In terms of area, it exceeds the Greenland ice mass by about 10 times. It contains 30 million cubic kilometers of ice. It has the shape of a dome, the steepness of the surface of which increases towards the coast, where in many places it is framed by ice shelves. The greatest ice thickness in Antarctica reaches 4800 m in some areas (in the east).
In the west, there is also the continental deepest depression - the Bentley depression (presumably of rift origin), filled with ice. Its depth is 2555 meters below sea level.
What is the average ice thickness in Antarctica? Approximately 2500 to 2800 meters.
Some more interesting facts
In Antarctica there is a natural body of water with the cleanest water on Earth. considered the most transparent in the world. Of course, there is nothing surprising in this, since there is no one on this mainland to pollute it. Here, the maximum value of the relative transparency of water (79 m) is noted, which almost corresponds to the transparency of distilled water.
In the McMurdo Valleys there is an unusual bloody waterfall. It flows out of the Taylor Glacier and flows into West Bonnie Lake, which is covered with ice. The source of the waterfall is a salt lake located under a thick ice sheet (400 meters). Thanks to salt, water does not freeze even at the lowest temperatures. It was formed about 2 million years ago.
The unusualness of the waterfall lies also in the color of its water - blood red. Its source is not exposed to sunlight. The high content of iron oxide in water, along with microorganisms that receive vital energy through the reduction of sulfates dissolved in water, is the reason for this color.
There are no permanent residents in Antarctica. There are only people living on the mainland for a certain period of time. These are representatives of temporary scientific communities. IN summer time the number of scientists, together with support staff, is approximately 5 thousand, and in winter - 1000.
The largest iceberg
The thickness of the ice in Antarctica, as noted above, is very different. And among the sea ice there are also huge icebergs, among which the B-15, which was one of the largest.
Its length is about 295 kilometers, its width is 37 km, and the entire surface area is 11,000 square meters. kilometers (more than the area of Jamaica). Its approximate mass is 3 billion tons. And even today, almost 10 years after the measurements, some parts of this giant have not melted.
Conclusion
Antarctica is a place of marvelous secrets and miracles. Of the seven continents, it was the last one ever discovered by explorers-travelers. Antarctica is the least studied, populated and hospitable continent on the entire planet, but it is also truly the most fabulously beautiful and amazing.
If you travel to the very south of South America, then first you get to Cape Froward on the Brunswick Peninsula, and then, having overcome the Strait of Magellan, to the Tierra del Fuego archipelago. Its extreme southern point is the famous Cape Horn on the banks of the Drake Passage, which separates South America and Antarctica.
If you go through this strait along the shortest path to Antarctica, then (of course, subject to a successful voyage) you get to the South Shetland Islands and further to the Antarctic Peninsula - the northernmost part of the continent of Antarctica. It is there that the furthest from South Pole Antarctic glacier - Larsen Ice Shelf.
For nearly 12,000 years since the last ice age, the Larsen Glacier has held a tight grip on the east coast of the Antarctic Peninsula. However, a study carried out in early XXI century, showed that this ice formation is undergoing a serious crisis and may soon completely disappear.
As the New Scientist noted, until the middle of the 20th century. the trend was the opposite: glaciers were advancing on the ocean. But in the 1950s, this process suddenly stopped and rapidly reversed.
Researchers from the British Antarctic Survey concluded that the retreat of glacial masses has accelerated since the 1990s. And if its pace does not slow down, then in the near future the Antarctic Peninsula will resemble the Alps: tourists will see black mountains with white caps of snow and ice.
According to British scientists, such a rapid melting of glaciers is associated with a sharp warming of the air: its average annual temperature near the Antarctic Peninsula has reached 2.5 degrees above zero Celsius. Most likely, warm air is sucked into Antarctica from warmer latitudes due to changes in habitual air currents. In addition, the ongoing warming of ocean water also plays a significant role.
Similar conclusions were reached in 2005 by Canadian climatologist Robert Gilbert, who published the results of his research in the journal Nature. Gilbert warned that the melting of the Antarctic ice shelves could set off a chain reaction. In fact, it has already begun. In January 1995, the northernmost (that is, the most distant from the South Pole, and therefore, located in the warmest place) Larsen A glacier with an area of 1500 square meters completely disintegrated. km. Then, in several stages, the Larsen B glacier collapsed, much more extensive (12 thousand sq. km) and located to the south (ie, in a colder place than Larsen A).
IN final act During this drama, an iceberg broke away from the glacier, with an average thickness of 220 m and an area of 3250 sq. km, which is larger than the area of Rhode Island. It suddenly broke up in just 35 days - from January 31 to March 5, 2002.
According to Gilbert's calculations, during the 25 years before this catastrophe, the temperature of the waters washing Antarctica rose by 10 ° C, while the average temperature of the waters of the World Ocean for the entire time that has elapsed since the end of the last ice age has grown by only 2-3 ° C. Thus, Larsen B was "eaten" relatively warm water, which for a long time undermined its sole. The melting of the outer shell of the glacier, caused by an increase in air temperature over Antarctica, also contributed.
Having broken up into icebergs and freed up the place on the shelf that it had occupied for ten millennia, Larsen B opened the way to sliding into the warm sea for glaciers lying either on solid ground or in shallow water. The deeper the "land" glaciers slide into the ocean, the faster they will melt - and the higher the level of the world ocean will be, and the faster the ice will melt ... This chain reaction will last until the last Antarctic glacier dissolves into the water, Gilbert predicted.
In 2015, NASA (US National Aerospace Administration) announced the results of a new study that showed that only a 1,600 sq. km, which is rapidly melting and is likely to completely disintegrate by 2020.
And just the other day, an even more grandiose event took place than the destruction of Larsen B. Literally in a couple of days, between July 10 and 12, 2017, from located even to the south (i.e. in an even colder place) and even more extensive (50 thousand sq. Km) of the Larsen C glacier, an iceberg with a mass of about 1 trillion tons and an area of about 5800 sq. km broke off. km, which would freely accommodate two Luxembourg.
The split was discovered back in 2010, the growth of the crack accelerated in 2016, and already in early 2017, the British Antarctic research project MIDAS warned that a huge fragment of the glacier was “hanging by a thread”. At the moment, one giant iceberg has moved away from the glacier, but glaciologists from MIDAS suggest that it may subsequently split into several parts.
According to scientists, in the near future the iceberg will move rather slowly, but it needs to be monitored: sea currents can carry it to where it will pose a danger to ship traffic.
Although the iceberg is huge, its formation did not in itself lead to a rise in the level of the world's oceans. Because Larsen is an ice shelf, its ice is already floating in the ocean rather than resting on land. And when the iceberg melts, the ocean level will not change at all. "It's like an ice cube in your glass of gin and tonic. It is already floating, and if it melts, the level of the drink in the glass does not change," Anna Hogg, a glaciologist from the University of Leeds (UK), explained intelligibly.
In the short term, the destruction of Larsen C is not worrisome, scientists say. Fragments of glaciers break off from Antarctica every year, part of the ice subsequently grows again. However, in the long term, the loss of ice on the periphery of the continent is dangerous because it destabilizes the remaining, much more massive glaciers - their behavior is more important for glaciologists than the size of icebergs.
First of all, the iceberg's breakaway could affect the rest of the Larsen C glacier. "We are confident, although many others disagree, that the remaining glacier will be less stable than it is now," says MIDAS project leader Prof. Alan Lachman. If he's right, then the chain reaction of the collapse of the ice shelves will continue.
With the liberation of the Antarctic Peninsula from glaciers, the prospect of its settlement will become more and more real. Argentina has long considered this territory to be its own, against which Great Britain objects. This dispute is directly related to the fact that the Falkland (Malvinas) Islands are located to the north of the Antarctic Peninsula, which the UK considers its own, and Argentina - its own.
The largest icebergs in history
In 1904, the tallest iceberg in history was discovered and explored off the Falkland Islands. Its height reached 450 m. Due to the imperfection of the then scientific equipment, the iceberg was not thoroughly investigated. Where and how he ended his drift in the ocean is unknown. He did not even have time to assign a code and a proper name. So he went down in history as the tallest iceberg discovered in 1904.
In 1956, the American military icebreaker U.S.S. Glacier discovered in Atlantic Ocean a large iceberg that has broken off the coast of Antarctica. The dimensions of this iceberg, which received the name "Santa Maria", were 97 × 335 km, the area was about 32 thousand square meters. km, which is larger than the area of Belgium. Unfortunately, at that time there were no satellites that could confirm this estimate. After making a circle around Antarctica, the iceberg broke and melted.
In the satellite era, the largest iceberg was B-15 with a mass of more than 3 trillion tons and an area of 11 thousand square meters. km. This Jamaica-sized block of ice broke off the Ross Ice Shelf adjacent to Antarctica in March 2000. After drifting quite a bit in open water, the iceberg got stuck in the Ross Sea and then broke up into smaller icebergs. The largest fragment was named iceberg B-15A. Since November 2003, it drifted in the Ross Sea, becoming an obstacle to the supply of resources to three Antarctic stations, and in October 2005 it also got stuck and broke into smaller icebergs. Some of them were seen in November 2006 only 60 km from the coast of New Zealand.
