The mysterious phenomenon was first noticed in 1970 – then these formations were much larger in area. They were re-observed in 2016 and 2017. For almost half a century, scientists could not explain the appearance of these giant holes, called polynyas (from the Russian word "polynya"). The other day in the journal Nature appeared the results of a study that revealed another mystery of Antarctica.
To solve a half-century riddle, scientists from the University of Washington enlisted the support of NASA to explore strange formations in ice with the help of satellites. It turned out that the giant ice voids are formed as a result of the coincidence of many environmental factors. As the results of the study showed, the cold ocean waters under the ice mix with warmer currents, raising the “heated” water to the surface, melting the ice.
"The water turns out to be warm enough to melt the sea ice. That's the whole secret," explains Ethan Campbell, lead author and Ph.D. of the University of Washington in Physical Oceanography.
The most interesting fact was that these formations appear almost at lightning speed. And so quickly that the holes on the ice appear literally suddenly. This is due to the presence of the Maud-Raise Plateau under water with a massive underwater mountain in the immediate vicinity of these holes.
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"This mountain is a real underwater Everest under the ocean. The shape and topography of a high mountain reinforce the movement of warm waters to the surface, creating strong streams of warm currents forming a kind of powerful jet of water spray that flushes cold ice," says Campbell.
The amount of heat generated by this warm water is very large. Moreover, warm currents are becoming "hot" as a result of global warming. Soon "polynyas" can become more common and have much larger sizes.
"As a result of the destruction of the Earth’s climate, such giant holes in Antarctica will be formed more and more often," the author concludes.