An enormous lake on the east coast of Antarctica has disappeared, inflicting 200 billion gallons of water to fade with no hint.

In the winter of 2019 on the Amery Ice Shelf, the third-largest ice shelf on the continent, round 21 billion to 26 billion cubic ft (600 million to 750 million cubic meters) drained actually shortly into the ocean. The lake’s disappearing act was seen the next summer season when scientists had been taking a look at satellite tv for pc pictures of the area. The findings are chronicled in a brand new examine.

“We believe a large crack opened briefly in the floating ice shelf and drained the entire lake into the ocean within three days,” Roland Warner, a scientist on the Australian Antarctic Program Partnership on the University of Tasmania who first noticed the key drainage on satellite tv for pc imagery, mentioned in a release. “The lake held more water than Sydney Harbor and the flow into the ocean beneath would have been like the flow over Niagara Falls, so it would have been an impressive sight.”

In the paper printed final week in Geophysical Research Letters, Warner and his coauthors discovered that the sudden drainage could have been brought on by meltwater within the ice. They theorize that there was meltwater saved beneath the deep, ice-covered lake, which put stress on the ice shelf and brought on a crack to open that despatched the water proper to the ocean, in a course of referred to as hydrofracturing. The drained lake left an enormous melancholy within the ice—round 4.24 sq. miles (11 sq. kilometers)—which shortly started to fill with meltwater once more final summer season.

Meltwater has been accountable for collapse and drainage on smaller ice cabinets all through the continent. But the Amery Shelf is round 4,593 ft (1,400 meters) thick, and this occurred in the midst of winter. That makes this occasion fairly uncommon. (Similarly leaky lakes have appeared in current winters on the floor of Greenland’s ice sheet hundreds of miles away within the Arctic as nicely.)

Attributing the lake’s disappearance completely to local weather change is just a little sophisticated. But what it does present is a useful case examine for a way floor ice soften in Antarctica—which is predicted to extend because the planet warms—can influence ice shelf stability. Antarctic ice cabinets additionally face threats from heat ocean water undercutting them, significantly in West Antarctica. The lack of ice in Antarctica impacts coastlines all over the world as a result of it contributes to sea degree rise.

“This abrupt event was apparently the culmination of decades of meltwater accumulation and storage beneath that insulating lid of ice,” mentioned Jonathan Kingslake, a co-author on the examine and researcher at Columbia University’s Lamont-Doherty Earth Observatory. “However, increasing amounts of meltwater flowing into deep, ice-covered lakes and causing hydrofracture of thick ice shelves should also be considered in assessments of Antarctica’s future.”