The New discoveries, Released Monday in Processes of the National Academy of Sciences, came from the analysis of satellite images. They show that the naturally occurring buffer system that prevents glaciers from speeding outwards is breaking down and that more ice may be unleashed at sea in the coming years.
Glaciers’SAsk the edges, ”Their floating ice shelves face high levels of friction that control the natural flow of ice, gradually weakening and in some cases breaking into pieces.
“The pressures that slow down the glacier are no longer in place, so the glacier is accelerating,” said Steff Lermit, a satellite expert at Delft Technology in the Netherlands, who led the new research with NASA and colleagues from other research institutes in France, Belgium, Austria and the Netherlands.
Although many images have been seen before, new analysis suggests that they are a sign of impending further decay.
“We already knew these were important glaciers in the future, but these pictures indicate to me that these ice shelves are in a very bad state,” Lermit said.
The Arctic sea ice is very close – but it has not been reached – this year’s record low. Last month, Canada lost much of it The last big Arctic ice wardrobe.
In Greenland, the ice shelf, which is still intact in the Northern Hemisphere, is sometimes called 79 North because its latitude (its full name is Neocolfzertzforden), lost a large iceberg, equivalent to two Manhattan Islands. According to Geographical study of Denmark and Greenland. Experts there have blamed the fracture on a strong general warming trend and temperature that has been “incredibly high” in northeastern Greenland in recent years.
Ice shelves are wide floating platforms that extend across the ocean surface at the outer edge of oceanic glaciers. As they float on the water, these shelves freeze over hills and islands and anchor themselves to bumps in the ocean. In this way, the shelves provide a braking mechanism for the natural outdoor flow of snow.
The cutting edges occur at the cutting edges, where fast-flowing snow meets the most stable and stable ice because it is often carried over a part of the landscape. In these places, the ice often breaks, which is a visible sign of powerful pressures.
But when those pressures are high, the ice breaks. That’s exactly what’s happening now in Western Antarctica, new research argues, as warm seawater has made ice shelves thinner from the bottom up, making them fragile.
At the same time, for the same reason, the glaciers began to flow outward automatically. The resulting forces led to the breaking of the cut-edge ice into pieces – i.e. the glacier, which was less controlled, could now add ice to the ocean even faster.
For the Pine Island Glacier, the new study was accelerated in 2016, with cracks and fraud at the cutting edge in 1999. The video, based on images from the European Space Agency’s Sentinel satellite, shows changes over the past four years:
Even more so is the Dwights Glacier. Here, again, the fracture of the cutting edge has increased in recent years:
The process of playing in Antarctica seems to have already been completed in some parts of Greenland, where one of the largest glaciers, the JacobShawn, no longer has a significant ice shelf. When it lost that shelf in 2000, Jacobshaw’s snow loss rate increased drastically.
79 Northern Glacier still has a large ice shelf, similar to some of Greenland’s other northern glaciers, but many of these have lost considerable size in recent decades.
“The new paper shows that the Amundsen Marine Empowerment ice shelves are the most of the Jacobshavan steps, but not all,” Ali said in an email. “[A] The warming sea ice shelves are thinner, which is reduced budding, which allows the floating ice to move faster, which contributes to some sea level rise and begins to break the sides of the ice shelves, but the rest may cause additional acceleration steps (further fracture and ice-layer loss). ”
Many ice shelves have already been found in Canada, Greenland and the warmer Antarctic Peninsula, where the former Larsen A and Larsen B ice shelves broke, not today.
“As we have seen on the Antarctic Peninsula for the past several decades, when ice shelves are damaged by climate change, their budding effect decreases, and ice currents accelerate and sea levels rise,” said Isabella Weligogna, a University of California commentator on Irvine California. “Increasing speed increases damage, which is not good news.
If a similar process occurs in the Amundsen Sea off western Antarctica, where Pine Island and Dwight are located, the sea level effects would be enormous.
Over the past six years, the western and central parts of the Pine Island ice shelf have shrunk by about 30 percent, with Lermit estimates that it is close to 1,500 square miles to 1,000 square miles. In other words, part of the size of Los Angeles has been lost.
“This cutting edge is so damaged that we think it presupposes this ice shelf for long-term instability,” Lermit said. “These are the first signs that the Pine Island ice shelf is disappearing. This damage is difficult to heal.”
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Glacier, Antarctica, Thwaites Glacier, Pine Island Glacier, Ice shelf, Sea level rise, Climate change
World news – US – Scientists say two large Antarctic glaciers are loosening out of their control