New York, Jul 8 (IANS): A team of researchers has discovered that an enormous, ice-covered lake in Antarctica vanished suddenly and scientists are worried that it could happen again.
In this disappearing act, an estimated 21 billion to 26 billion cubic feet (600 million to 750 million cubic metres) of water -- roughly twice the volume of San Diego Bay -- drained into the ocean.
According to the study, the event occurred during the 2019 winter on the Amery Ice Shelf in East Antarctica, Live Science reported.
The authors who used satellite observations to capture the shocking vanishing act say the lake drained in roughly three days after the ice shelf beneath it gave way.
"We believe the weight of water accumulated in this deep lake opened a fissure in the ice shelf beneath the lake, a process known as hydrofracture, causing the water to drain away to the ocean below," said lead author Roland Warner at the University of Tasmania.
He added that once the water was released, "the flow into the ocean beneath would have been like the flow over Niagara Falls, so it would have been an impressive sight".
Hydro fracturing occurs when water -- which is denser and, therefore, heavier than ice -- rips open gigantic cracks in ice sheets -- and then, drains into the sea.
This leaves behind a gigantic fissure that compromises the structural integrity of the sheet as a whole.
As meltwater lakes and streams multiply across the surface of Antarctica, researchers are concerned that growing volumes of surface meltwater could cause more hydrofracturing events, which could cause ice shelves, including the parts which are anchored to the ground, to collapse, thus elevating sea levels above current projections.
"Antarctic surface melting has been projected to double by 2050, raising concerns about the stability of other ice shelves," the team wrote in their study, which was published June 23 in the journal Geophysical Research Letters.
"Processes such as hydrofracture and flexure remain understudied and ice-sheet models do not yet include realistic treatment of these processes," they added.