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A recent study published in the US scientific journal. procedures 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 an ever-increasing rate. According to the study, the Pine Island and Thwaites glaciers alone contribute to their melting already about 5 percent of the global increase in seawater, a phenomenon that in recent years has been greatly accelerated due to global warming. Further reduction in ice could have dangerous effects not only on the seasonal integrity of the rest of the Antarctic glaciers, but also on water levels on the rest of the planet.
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The reduction of the ice sheet in Antarctica mainly affects the Antarctic Peninsula, which extends into South America, and the area of West Antarctica, where the two glaciers meet. In these two areas, the ice melts faster both because of the air temperature, which is higher than usual, and because the marine waters that pass under them are warmer than a few years ago.
As a general rule, the ice sheets act as a “plug”, keeping both the glaciers that cover the continental part and those that surround it stable and preventing them from sliding towards the sea. However, these ice caps are gradually melting and thus the cap lacks its natural protective barrier. Satellite images analyzed in the study highlighted the detachment of large chunks of ice and showed that even more chunks of the ice sheet are at risk of detaching and collapsing in the sea.
This means that due to global warming in the coming years the water level could rise more and with enormous consequences, if we take into account 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, a professor at the University of California and an expert glaciologist on sea level rise, told the Washington Post that the acceleration of the contraction process of the two glaciers in Antarctica “is not good news.”
The study found that Pine Island’s ice shrinking process had begun in 1999 and has accelerated since 2016. Scientists have calculated that the central and western parts of the glacier have decreased by 30 in the past four years. percent, going from about 3,900 square kilometers to about 2,600: to give an idea, a patch of ice roughly the size of the city of Los Angeles was lost.
However, according to experts, the situation of the Thwaites glacier is even more critical. As a study published in Sciences in fact, in 2009, the shrinking Thwaites ice could cause an even larger part of the Antarctic ice sheet to collapse, which contains enough ice to cause, when completely melted, an increase of more than three meters.
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The significant 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 during the last 12 years. Among other things, in 2018, the most authoritative study published to date had shown that Antarctica had already lost three trillion tons of ice in the space of 25 years. In addition, in February this year, for the first time in Antarctica, temperatures above 20 ° C were recorded.
If the shrinking Antarctic ice sheet is combined with the fact that even the Arctic glaciers are not doing well, the global situation raises considerable concern.
Between July 30 and August 4, in the Canadian part of the Arctic Ocean, the Milne ice shelf collapsed, an ice shelf twice the size of the city of Bergamo, while on September 14 from the ice cap Greenland’s most intact glacier, the N79 (Nioghalvfjerdsfjorden), broke a patch of ice as large as Piacenza. In both cases, according to experts from the Geological Survey of Denmark and Greenland, the “progressive disintegration” of Arctic glaciers is due to the fact that temperatures in these areas in recent years have been “incredibly high”.
– Read also: The underwater world, photographed
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