A massive ice-covered lake in Antarctica vanished within days, raising alarm bells in the scientific community over the dangerous trends of climate change and global warming. 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.
Researchers captured high-resolution satellite images showing an abrupt change on East Antarctica’s Amery Ice Shelf in June 2019, where meltwater stored in a deep, ice-covered lake drained through to the ocean below, leaving a deep, uneven 11 square kilometre depression of fractured ice. The lake vanished within three days after the ice shelf underneath collapsed.
“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”.
Researchers said that surface melting over Antarctica’s floating ice shelves is predicted to increase significantly during the coming decades, but the implications for their stability are unknown. The Antarctica peninsula has been witnessing significant melting driven ice shelf collapses as researchers try to understand how meltwater forms, flows and alters the surface, and that rapid water-driven changes are not limited to the summer season alone.
The effects of global warming are also visible in the Arctic, where recently the “last ice area” showed signs of melting earlier than expected. The Last Ice Area is part of the Arctic, where the floating sea ice is so thick that it’s likely to withstand global warming for decades. But a ship has now sailed through an opening created by melting.
The opening, documented by scientists aboard a German icebreaker, popped up in late July and August in the Wandel Sea north of Greenland. Mostly it was due to a freak weather event, but thinning sea ice from decades of climate change was a significant factor, according to a study Thursday in the journal Communications Earth and Environment.
