The thinning of the ice-like “glue” that holds the crushed ice together can cause the ice shelves to collapse. Antarctica, According to a new study.
Ice shelves are huge ice shelves that accumulate over thousands of years. Live science previously reported.. However, ice shelves are collapsing due to rising temperatures and rising seawater temperatures. Many of Antarctica’s ice shelves have been destroyed or collapsed in the last two decades, according to new research, but it is unclear exactly what is accelerating ice loss.
To understand this, a group of glaciologists zoomed in on the Larsen Ice Shelf rift in Antarctica, which delivered Delaware size. iceberg It was called A68 in July 2017.
The division of the A68, an iceberg with an area of approximately 2,240 square miles (5,800 square kilometers), has reduced the size of Larsen C by 12%. Live science previously reported.. The Larsen Ice Shelf is the third ice shelf on the western peninsula of Antarctica that has lost a large amount of ice in the last 20 years.
The general theory was that these splits were caused by a process called hydrofracturing, in which a pool of melted ice on the surface of the ice shelf penetrated through the cracks and expanded when frozen again. Professor Eric Lignott is a co-author.Systems Science at the University of California, Berkeley Said in a statement.. “But that theory cannot explain how iceberg A68 can break from the Larsen Ice Shelf in the midst of winter in Antarctica, where no molten pool existed.”
Rignot and his colleagues analyzed hundreds of crevices or crevices in the Larsen Ice Shelf using ice sheet and sea level change models developed by NASA, as well as data from satellite and research aircraft. They zoomed in on 11 cracks and modeled 3 melting scenarios.
According to the statement, two of the three scenarios are a mixture of wind-blown snow, frozen seawater, and ice shelf debris that resides inside and around the lift and normally functions to block the crevices. Focused on the role of the “Melange”.
In the first scenario, glaciologists modeled what would happen if the ice shelf melted and thinned. Second, they modeled what would happen if the ice melange became thin. And the third modeled what would happen if both the ice shelf and the melange were thin. Their simulations showed that thinning the melange controls the rate at which the rift opens.
If the ice shelves were thin, but the melange was still as thick, the lift spread slowed over time. In other words, the melange acted as a “healing” glue, fusing some of the cracks together. Thinning both the ice shelf and the melange slows the rift to widen, but not as much as in the first scenario. If the ice shelves remain the same and the melange becomes thinner, as in the third scenario, the average annual rate of lift expansion increased from 249 feet to 367 feet (76 meters to 112 meters).
Like sea ice, melange is susceptible to warming seas and rising temperatures. “The melange is thinner than ice in the first place,” said Eric Larour, a research scientist and lead author at NASA’s Jet Propulsion Laboratory, in a statement.
Thinning of only 32 to 66 feet (10 to 20 m) of melange is sufficient to reactivate the rift or begin thawing it to trigger a major labor event, the authors wrote in a study. They write that reactivating the lift can cause hydraulic fracturing on the surface of the ice sheet after the ice shelves have receded for decades.
“Thinning the ice melange that glues a large piece of floating ice shelf is another way. Climate change Antarctica’s ice shelves could recede rapidly, “Lignott said. “With this in mind, we may need to rethink our estimates of the timing and extent of sea level rise due to the loss of polar ice. We smashed more than we expected.”
The findings were published online in the journal on September 27th. Minutes of the National Academy of Sciences..
Originally published in Live Science.
Melting “glue” may have driven the world’s largest iceberg to its fate, new research discovers
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