Melting glaciers in Antarctica. Scientists: Antarctic glaciers are melting from the inside

The largest glacier on the island of Iceland, Vatnajökull, began to melt: giant craters appeared in it, more than a kilometer in diameter and hundreds of kilometers deep, as well as cracks.

As with many glaciers in Iceland, there are several volcanoes and volcanic lakes under the Vatnajökull Glacier. Several glacial lakes feed the glacier. It occupies 8,133 km² or 8% of the area of Iceland. It is the third in terms of territory (after the glacier of the North Island ( New earth, Russia, area -20500 km²,) and the Austfonna glacier (Spitsbergen archipelago, Norway, area - about 8 492 km²), and in terms of volume is the largest in Europe -3,100 cubic km.

The reason for the melting of the Vatnajökull glacier is not known, but scientists suggest that one of the reasons is changing climatic conditions on Earth.

The glacier, like a dome-dam, holds back a huge glacial lake inside itself, and when it melts, as a result, flooding in Iceland and volcanic eruptions are possible.

« Global climate change is already affecting the health, living conditions and livelihoods of people on all continents of the Earth. The observed increase in the growth of the dynamics of global natural disasters indicates that in the coming decades they will lead to catastrophic consequences on a global scale for civilization as a whole, unprecedented in the history of mankind, victims and destructions. "(From a scientific report )

"Traces of this melting remain invisible to satellites, as the snow on the ice surface absorbs this water and acts as a buffer that prevents the formation of melt lakes and water flows that may occur on some Antarctic glaciers. On the other hand, we cannot yet rule out the fact that "open" water can still appear somewhere ", - says Julien Nicolas (Julien Nicolas) from Ohio University (USA).

Annually, the Antarctic ice sheet loses up to 2.8 thousand cubic kilometers of ice, and in the last decade the ice cover has been decreasing faster and faster. For a long time it was believed that this is due to the accelerated formation of icebergs, however, American climatologists in June 2013 found that slightly more than half of the volume of "disappeared" ice was melted warm currents washing the underwater part of the Antarctic ice sheet through a kind of canals - "rivers" at the foot of the glaciers.

Nicholas and his colleagues found that the melting of Antarctic ice is coming no less quickly and on their surface, observing the state of glaciers in the west of Antarctica, the most vulnerable part of its ice cover, in December 2015 - January 2016, at the height of the years in the southern hemisphere of the Earth.

These observations, as scientists say, they were not using satellites, but special mobile weather stations installed over the entire area of the Ross glacier. Initially, according to Nicholas, his team did not study how glaciers were melting, but watched how clouds affect the amount solar heat reaching the surface of Antarctica.

They managed to discover a more interesting and alarming trend - it turned out that glaciers with an area of about 770 thousand square kilometers began to melt not only from below, at the bottom of the ice cover, but also "from above", on the border between air and ice.

The reason for this massive melting of glaciers, scientists suggest, was the increase in El Niño, a climatic phenomenon in the tropical region. The Pacific associated with the nature of the movement of currents. The activation of El Niño leads to an increase in temperatures in the temperate and circumpolar latitudes due to the intensification of the transfer of warm air from the equatorial regions of the planet to the circumpolar regions, and its unusually bright character in 2015 and 2016 is today considered one of the main causes of the abnormal heat in Russia and in other countries. ...

As Nicholas notes, the magnitude of the melting associated with El Niño was actually quite modest - it was hampered by unusually strong westerly winds that chilled the Ross Glacier and other regions of western Antarctica. In the future, "strong" El Niños will occur more and more often, and most of these episodes will not coincide with increased westerly winds, which will further accelerate the melting of glaciers on the surface.

Ice in the west of Antarctica split from the inside, scientists sayThe ice sheet in western Antarctica is cracked from the inside, which may explain why large icebergs are constantly breaking away from it and why it is crumbling so quickly.

If these glaciers completely collapse in the near future, the sea level, according to scientists, could rise by about three meters and reach the values characteristic of the last interglacial period, which ended 125 thousand years ago.

Huge sections of glaciers in Antarctica, comparable in area to France, were melting not only "from below", but also on the surface at the height of last year's summer, scientists who published an article in the journal Nature Communications discovered.

Annually, the Antarctic ice sheet loses up to 2.8 thousand cubic kilometers of ice, and in the last decade the ice cover has been decreasing faster and faster. For a long time it was believed that this is due to the accelerated formation of icebergs, however, American climatologists in June 2013 found that slightly more than half of the volume of "disappeared" ice was melted by warm currents washing the underwater part of the Antarctic ice sheet through peculiar channels - "rivers ", at the foot of the glaciers.

Nicholas and his colleagues found that the melting of Antarctic ice is no less rapid on their surface, observing the state of the glaciers in the west of Antarctica, the most vulnerable part of its ice cover, in December 2015 - January 2016, at the height of summer in the southern hemisphere of the Earth.

Mobile Antarctic Station AWARE

The reason for this massive melting of glaciers, scientists suggest, was the increase in El Niño, a climatic phenomenon in the tropical Pacific Ocean associated with the nature of the movement of currents. The activation of El Niño leads to an increase in temperatures in the temperate and circumpolar latitudes due to the intensification of the transfer of warm air from the equatorial regions of the planet to the circumpolar regions, and its unusually bright character in 2015 and 2016 is today considered one of the main causes of the abnormal heat in Russia and in other countries. ...

Antarctica is the least explored continent located in the south of the globe. Most of its surface is covered with ice up to 4.8 km thick. Antarctic ice shield contains 90% (!) of all the ice on our planet. It is so heavy that under it the continent sank by almost 500 m.Today the world is observing the first signs of global warming in Antarctica: large glaciers, new lakes appear, and the soil loses its ice cover. Let's simulate what happens 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 be reduced by a third. The mainland will become virtually unrecognizable. There are numerous mountain ranges and massifs under the ice. Western part will definitely become an archipelago, and the eastern one will remain the mainland, although taking into account the rise ocean waters for a long time she will not keep this status.

At the moment, on the Antarctic Peninsula, islands and coastal oases, there are many representatives flora: flowers, ferns, lichens, algae, moreover, their diversity has been gradually increasing recently. There are fungi and some bacteria, and the coast is occupied by seals and penguins. Already now, on the same Antarctic Peninsula, the appearance of tundra is observed, and scientists are sure that with warming there will be trees and new representatives of the animal world. By the way, Antarctica holds several records: the lowest recorded temperature on Earth - 89.2 degrees below zero; the largest crater on Earth is located there; the strongest and longest winds. Today, there is no permanent population on the territory of Antarctica. There are only employees of scientific stations, and sometimes tourists visit it. With climate change, the former cold mainland may become suitable for permanent human habitation, but now it is difficult to speak about this with certainty - everything will depend on the prevailing climatic situation.

How will the world change due to melting glaciers?

The rise in the water level in the oceans So, scientists have calculated that after the melting of the ice cover, the level of the oceans will rise by almost 60 meters. And this is a lot and will be equated with a global catastrophe. Coastline will move significantly, and the current 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 undergo too much flooding - basically, residents of coastal settlements will have to be resettled.

The Black Sea will grow - in addition to the northern part of Crimea and Odessa, Istanbul will also take over. Signed cities that will be under water The Baltics, Denmark and Holland will almost completely disappear. In general, such European cities 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 on 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 more large coastal cities.

What will happen with 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 ecologists, 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 disturbed. Receipt of large quantities fresh water into the oceans will surely 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.

Quantity 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 lack of fresh water. And not only because of the arid climate. The fact is that the deposits of snow in the mountains provide vast territories with water, and after its melting, such a benefit will no longer exist.

Economy

All this will greatly affect the economy, even if the flooding process is gradual. Take the United States and China, for example! Like it or not, these countries have a very strong impact on the economic situation around the world. In addition to the problem of resettlement of tens of millions of people and the loss of their capital, the states will lose almost a quarter of their production capacity, which will ultimately hit the global economy. And China will be forced to say goodbye to its huge commercial 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 is still cause for concern, and provide compelling evidence.

Not so long ago, British scientists analyzed 50 million. satellite imagery Antarctic ice sheets and came to the conclusion that they are melting very rapidly. In particular, the giant Totten glacier, the size of which is comparable 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, is 12,000 years old.

According to the BBC, Antarctica loses a whopping 160 billion ice a year. Moreover, this figure is growing rapidly. Scientists say that they did not expect such a rapid melting of the southern ice.

The most unpleasant thing is that the very process of melting glaciers even more affects the increase greenhouse effect... The fact is that the ice sheets of our planet reflect part sunlight... Without this, heat will be retained in the Earth's atmosphere in large volumes, thereby increasing the average temperature. And the growing area of the World Ocean, the waters of which collect heat, will only aggravate the situation. Besides a large number of melt water is also detrimental to glaciers. Thus, ice reserves not only in Antarctica, but throughout the entire globe, are melting faster and faster, which ultimately threatens with big problems.
Conclusion

Scientists have very different opinions about the melting of the Antarctic ice sheet, but what is known for certain is that humans greatly affect the climate by their activities. If humanity does not solve the problem of global warming in the next 100 years, then the process will be inevitable.