Anomalous hotspot discovered in Antarctica



Japanese scientists have discovered that the ice is melting at an odd speed at the bottom of the Shirai ice, located in eastern Antarctica.

According to Nature Communications, the 58th Japanese scientific expedition to the Shirai Ice has detected an anomalously hot area beneath the ice sheet.

In January and February 2017, this mission had an opportunity to conduct studies and observe the Cherasy ice, after a huge piece of it had separated, and the icebreaker was able to enter Lyuttsov-Holm Bay.

The mission personnel were able to collect the necessary information on water temperature, salinity and oxygen level at 31 points.  After studying and comparing it with radar monitoring data for the state of ice, water currents and winds in the region, they modeled the ocean circulation under the ice sheet.

"We found that the ice is melting at a speed of 7-16 meters per year in the lower layer," said Daisuke Hirano, head of the scientific expedition from Hokkaido University. "This is higher than the melting speed of Toten ice, which was thought to be melting very quickly 10-11 meters per year."

It turns out that the cause of this phenomenon is the outflow of warm water under the Lyuttsov-Holm Bay ice.  It runs in a deep valley and then rises up below the ice sheet, causing it to melt.

The scientists discovered that this melting continues throughout the year, and is affected by the intensity and direction of the coastal winds that change with the seasons, as the summer subsides, which increases the flow of warm water and thus increases the speed of ice melting.

It should be noted that most of the previous studies on the relationship between the ocean and ice included the ice of the western region of Antarctica, and it did not concern the region's ice in some eastern regions, so it was believed that the water under the ice is cold, which protects the ice of the eastern region from melting.  But this turned out to be untrue.

The ice of the eastern region of Antarctica is the largest reservoir of fresh water in the world, and if this ice melts completely, it will lead to a rise in the water level in the global ocean by 60 meters.

According to current projections, the melting of ice at current rates will cause the water level in the global ocean to rise by one meter by the year 2100 and by 2500 by 15 meters.

The Source: arabic.rt.com


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