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It's no secret that the world's ice is shrinking as global temperatures rise. Despite everything, the sudden destabilization of a remote ice cap in the Russian High Arctic has brought scientists to launch words like "extraordinary" and "unprecedented".
This is because the Vavilov Ice Cap, located on Revolution Island between the Kara and Laptev Seas, is located in a polar desert, a region whose freezing temperatures and dry weather should keep the ice firmly attached to the sea. underlying substratum. Instead, part of Vavilov's ice is now heading to the ocean, moving a few centimeters of movement a day in the 90's to 82's. feet per day in 2015.
The results raise the disturbing possibility that other polar desert icecaps – miniature ice caps found mostly at high altitudes – may be subject to sudden and rapid destabilization as the Earth warms up.
"It is surprising that the Vavilov Ice Cap, as far as an apparently stable ice cap with a bed almost entirely frozen, almost entirely above sea level, could quickly pour such a large proportion of its ice into the sea. ocean. short period, "write the scientists in a new article in Earth and Planetary Science Letters.
The research team, led by geologist Mike Willis of the University of Colorado at Boulder, used satellites operated by DigitalGlobe to track the speed and thickness of the ice cap over time . Around 2010, they noticed an ice acceleration in an outlet glacier around the western margin of the cape, followed by a much faster surge in 2015. While this area of ice did not only 400 meters (1952-1985) The ice front swept more than 5 km into the ocean between 2015 and 2016. The acceleration is shown in the satellite image time above.
The authors suspect that the sudden surge was due to the fact that the bottom of the ice became wetter, perhaps due to the melting of the surface meltwater through the cracks and the progression of the glacier front over slippery sediments. While ice has somewhat slowed its progress in 2017, researchers say it's "unlikely" that the hood recovers the lost mass due to global warming.
Stef Lhermitte, an expert in satellite and remote sensing from the Delft University of Technology who studies glaciers and ice caps around the world, described what was happening to Vavilov's icecap in an e-mail as "remarkable" addressed to Earther.
"[W]We know about 2300 glaciers in full swing, but there is no historical evidence of the behavior of the Vavilov Ice Cap, "said Lhermitte. "Although extrapolation and long-term prediction of similar events are difficult, it shows that boundary conditions may change rapidly in cold-climate environments."
According to the study, ice caps like Vavilov cover about 170,000 square miles of the surface of our planet and hold a potential foot of additional sea level rise. As satellites follow the icy regions of the Earth are improving, it may be useful to take a closer look at these areas to see if they are really as stable as we thought. It would not be the first time that we questioned this hypothesis.
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