For a long time, scientists did not pay special attentionmelting glaciers in Antarctica. It seemed that this process is long, stable and does not pose any serious threat to humanity. But then, as the saying goes, “something went wrong,” namely, the increasing speed with which the ice cover on the mainland decreases. For example, it is known from official data that back in the 1980s, the continent was losing about 40 billion tons of ice annually. Over the past ten years, this figure has increased to 252 billion tons of ice per year. Moreover, the glaciers began not only to actively melt, but also to break away from the mainland, turning into giant icebergs. As a result, the melting of Antarctic ice is further accelerated. At the beginning of the year, the attention of scientists and the media was riveted on the A74 iceberg. However, the concern is not caused by this iceberg itself, but by the processes that may follow in the near future as a result of glacial imbalance.
In recent years, in Antarctica, not only is the melting of glaciers accelerated, but the number of faults is also increasing.
Why the glacier A74 is dangerous
Scientists knew that from the Brant Ice Shelfsooner or later a big iceberg will break away. Nevertheless, the appearance of the crack took them by surprise, in the sense that they did not expect such a rapid process.
The area of this giant ice floe is 1270square kilometer. For comparison, it is much larger than the area of New York or Kiev, and slightly less than the area of St. Petersburg, which is 1439 square meters (yes, St. Petersburg is almost twice as large as New York in terms of its area).
However, this is far from the largest glacier,which has been chipping away in the last few years. The leader is the A-68a iceberg, which covers an area of 5800 square kilometers. By themselves, these glaciers can cause a catastrophe only on a local scale if they crash into an island located in the southern hemisphere, or the mainland.
Giant iceberg A74 "kissed" the ice shelf
Recently, A74 attracted the attention of scientists, soas he headed towards the continental shelf, from which he broke away. This process was especially closely watched by British scientists, since their research laboratory is located on the Brant Ice Shelf, although it is mothballed. In addition, scientists were alarmed by the fact that the ice shelf has a huge crack, which was named Chasm 1. Accordingly, the impact could provoke ice breakaway.
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The collision did happen, but it wasnot strong and short-term, so it passed without consequences. Therefore, scientists called it "the kiss". Earlier, iceberg A-68a was heading towards South Georgia Island, threatening to destroy penguins and other local fauna. However, it fell apart earlier, before reaching the island.
What Happens on the Brant Ice Shelf
The Brant Glacier is in the northern partmainland, about 4800 km from the nearest point in South America. According to experts, the shelf contains large faults, as a result of which in the coming months icebergs of even larger size than the A74 may go free floating.
Fracture on the Brant Ice Shelf will soon lead to the formation of a new giant iceberg
Scientists are especially closely watching the faults.Halloween Crack and Chasm 1. They started heading towards each other quickly back in 2019. Their combination will mean that another iceberg has formed, the area of which is about 1,700 square kilometers. At the moment they are at a distance of about two kilometers from each other.
Why are breaking glaciers dangerous?
At the moment, there is no scientific evidence thatthat faults in glaciers arise due to global warming. Nevertheless, this version is highly probable. In addition, it is known that in some parts of Antarctica, warm ocean waters erode the bottom of the ice sheets. It is possible that this process is also associated with the appearance of faults and icebergs.
Note that several largeicebergs such as A74 and A76 are not capable of leading to a serious catastrophe on a planetary scale. However, the danger is fraught with the unpredictability of further processes. That is, no one can say for sure how the breakaway of one or several glaciers will affect neighboring glaciers. It is quite possible that their destabilization will lead to the appearance of even more icebergs and accelerated ice melting. Then a catastrophe is not excluded.
Thwaites is the most dangerous glacier on the planet
The greatest danger at the momentis the Thwaits glacier, which is moving at a fairly high speed towards the Amundsen Sea. He overcomes 11 meters per day. Its area is about 120 thousand square kilometers. Scientists at the University of Washington call it "the threshold of the system." That is, after it gets into the water, the entire system of glaciers will lose balance. As the glaciologist Knut Kristianson says, this process is not like the slow melting of a glacier, but the collapse of a house of cards.
What other global catastrophes pose a real threat to humanity in the near future? Read about it on our Yandex.Zen channel.
About half of the world's population live inwithin 80 km of the oceans coastline. Already, climatologists are reporting that glaciers are beginning to melt faster and faster. However, the process of raising the water level is still extremely slow. At this speed, people will have time to take measures to avoid a disaster, for example, they can build dams.
However, if the balance of glaciers is imbalanced, the water level can rise very quickly, and then people will not have time to make decisions.