New discoveries in Antarctica shed light on the impact of climate change — MercoPress

New findings in Antarctica shed light on the impact of climate change

Thursday, November 17, 2022 – 09:50 UTC


The discovery means better predictions could be made about how the continent’s ice sheets might behave if global warming continues unchecked.

Researchers from Imperial College London have described a recent discovery in Antarctica as a clear sign of ice loss due to climate change. According to their expert opinion, the newly discovered 460-kilometer-long (285-mile) river beneath the ice of Antarctica accelerated the loss of ice mass.

This discovery was made in an almost inaccessible area of ​​East and West Antarctica that extends to the Weddell Sea. Key to this discovery was the use of airborne radar soundings that can scan ice. “We are now beginning to understand that there are whole systems out there, interconnected by vast river networks, as they might be if it weren’t for thousands of meters of ice on them,” he said. scientist Martin Siegert, one of the authors of the research and a scientist at Imperial College London.

The mysterious river was detected by flying a plane over Antarctica to collect radar data, which they combined with models of how water would move across the continent.

The team determined that the Hidden River flows at three times the flow of the Thames in London.

The finding, which was shared in a paper published in Nature Geosciences last month, means the underside of Antarctic ice has more active water flow than scientists previously thought. This could make it more susceptible to human-induced climate change.

Siegert also mentioned that this river system could be the cause of the melting in this part of Antarctica. “The amount of ice that melts and the rate at which it melts is related to the slipperiness of the base of the ice,” he explained. The significance of this study is that there would be enough ice in the reference region of the study to raise global sea level by more than four meters. The team leading the research is already working to find out if there are more rivers under the ice.

In Greenland, for example, hot summer temperatures are melting the summit ice, causing large amounts of water to run off the surface and seep through deep crevices. In Antarctica, however, the summers are colder and the ice surface does not melt much. For this reason, scientists had assumed that there was not much water under the ice caps.

The study also suggests that Antarctica is melting at the base of the ice sheets, which in turn causes these rivers to form. A formation of fresh water which, if under high pressure, can accelerate the process of melting ice as the base of the glacier becomes unstable. The four ice masses that support the river system are Institute Ice Stream, Mӧller Ice Stream, Support Force Glacier, and Foundation Ice Stream/Academy Glacier.

Research has shown that Antarctic ice is melting from the bottom, caused by friction as it rubs against the land, as well as the Earth’s natural geothermal heat. Scientists have determined that the amount of ice that melts is not huge, no more than a few millimeters per year. But because the ice surface is so large, even a millimeter of meltwater can add to a massive, fast-flowing river.

The research comes months after NASA’s Earth Observatory discovered that a large expanse of sea ice broke off the Antarctic Peninsula after more than 10 years anchored to the coast. Scientists have raised the possibility that the hot and humid southern hemisphere summer may have been the cause of this melting.

Earlier this month, arguably the world’s largest iceberg reappeared in Drake Passage. The so-called A-76A iceberg appeared in the Sickle Sea, the arm of the sea that separates South America from Antarctica. It is currently about 500 kilometers north of its natural position. The main iceberg of Iceberg A-76 broke off from the Ronne Ice Shelf in Antarctica in May 2021.

According to the Aquae Foundation, Antarctica is the part of the Earth that suffers the most from global warming. The average surface temperature of the planet has increased since the end of the 19th century by 1.1 degrees Celsius. A change that has occurred to this day due to the increase in carbon dioxide and other emissions into the atmosphere made by humans. In Antarctica, for example, the climate has increased by 3°C.

The river is a significant advance for scientists’ understanding of Antarctica’s subglacial hydrology, meaning better predictions could be made of how the continent’s ice sheets might behave if global warming continues. continued without control.

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