A recent studio published in the US scientific journal Proceedings of the National Academy of Sciences found that two huge glaciers found in the Amundsen Sea, in the western part of the Antarctic Ice Sheet, are progressively shrinking and breaking up at ever-increasing rates. According to the study, the Pine Island and Thwaites glaciers already contribute about 5 percent of the global rise in sea water, a phenomenon that has been greatly accelerated in recent years by global warming. Further ice reduction could have dangerous effects not only on the seasonal integrity of the rest of the Antarctic ice sheets, but also on the water level situation in the rest of the planet.
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The reduction of the ice sheet in Antarctica mainly concerns the Antarctic Peninsula, which extends towards South America, and the area of Western Antarctica, where the two glaciers are located. In these two areas the ice melts faster both because of the air temperature, which is higher than usual, and because the sea waters that pass under them are warmer than they should be.
As a rule, the ice sheets act as a “plug”, keeping the ice sheet and glaciers on the continental part of Antarctica stable, and preventing them from sliding towards the sea. These layers of ice, however, are gradually melting and so the ice cap is without its natural protective barrier. The satellite images analyzed in the study highlighted the detachment of large portions of ice and showed that even more portions of the ice sheet are at risk of detaching and collapsing into the sea.
This means that because of the global warming in the next few years the water level could rise further and with enormous consequences, if we consider that even a few more centimeters can cause serious problems in areas where the coasts are low and more exposed to the tides.
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Isabella Velicogna, University of California professor and glaciologist expert in rising seas, he said al Washington Post that the acceleration of the shrinking process of the two glaciers in Antarctica “is not good news.”
The study found that Pine Island’s ice reduction process had started in 1999 and has accelerated since 2016. Scientists have calculated that the central and western parts of the glacier have decreased by 30 over the past four years. percent, going from about 3,900 square meters to about 2,600: to give an idea, a portion of ice roughly the size of the city of Los Angeles was lost.
According to experts, however, the situation of the Thwaites glacier is even more critical. As one had already assumed studio came out on Science in fact, in 2009, the reduction of the Thwaites ice could cause the collapse of an even larger part of the Antarctic ice sheet, which contains enough ice to cause a rise of more than three meters.
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The remarkable reduction and loss of ice in Antarctica has been a phenomenon that has been observed for some years: according to data from the World Meteorological Organization, in the last fifty years the average temperatures of Antarctica have increased by at least 3 ° C and the 87 percent of glaciers near the west coast have shrunk, particularly over the past 12 years. Among other things, in 2018 it studio most authoritative released so far had shown that Antarctica had already lost three trillion tons of ice within 25 years. In addition, in February of this year one was registered for the first time in Antarctica temperature above 20 ° C.
If the reduction of the Antarctic ice sheet is combined with the fact that even the Arctic glaciers are not doing well, the global situation raises considerable concern.
Between 30 July and 4 August last in the Canadian part of the Arctic Ocean collapsed Milne Ice Shelf, an ice shelf twice the size of the city of Bergamo, while on September 14 from the most intact ice cap in Greenland, the N79 (Nioghalvfjerdsfjorden), a portion of ice as large as Piacenza broke off. In both cases, according to experts from the Geological Survey of Denmark and Greenland, the “progressive disintegration” of Arctic glaciers is due to the temperatures that in these areas in recent years have been “incredibly tall».
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