Rapid melting of huge Antarctic glacier -catastrophic impact of global heating.

Antarctic ‘doomsday glacier’ may be melting faster than was thought

Antarctic ‘doomsday glacier’ may be melting faster than was thought

Study finds more relatively warm water is reaching Thwaites glacier than was previously understood, Guardian, Matthew Taylor Fri 30 Apr 2021, An Antarctic glacier larger than the UK is at risk of breaking up

after scientists discovered more warm water flowing underneath it than previously thought.

The fate of Thwaites – nicknamed the doomsday glacier – and the massive west Antarctic ice sheet it supports are the biggest unknown factors in future global sea level rise.

Over the past few years, teams of scientists have been crisscrossing the remote and inaccessible region on Antarctica’s western edge to try to understand how fast the ice is melting and what the consequences for the rest of the world might be.

“What happens in west Antarctica is of great societal importance,” said Dr Robert Larter, a scientist with the British Antarctic Survey and principal investigator with the International Thwaites Glacier Collaboration, the most ambitious research project ever carried out in Antarctica. “This is the biggest uncertainty in future sea level rise.”……….

Wahlin said the front of the Thwaites glacier was resting on a number of “pinning points” under the sea. But as relatively warm water from the deep ocean increased the melting, she said, these would be lost, breaking up the ice and allowing warm water further under the ice. This would speed up the flow of the glacier into the sea……..

The worst-case scenarios for Thwaites are grim. It is the widest glacier on the planet, more than 1km deep and holds enough ice to raise the sea level by 65cm.

Ice loss has accelerated in the last 30 years and it now contributes about 4% of all global sea level rise. Experts say this could increase dramatically if the ice at the front of Thwaites breaks up, with knock-on effects for other glaciers in the area.

To heighten scientists’ concerns, west Antarctica has been one of the fastest-warming place on Earth in the past 30 years, and since 2000 it has lost more than 1tn tons of ice.

Last year, a team of British scientists discovered cavities half the size of the Grand Canyon under Thwaites that, like decay in a tooth, allow warm ocean water to erode the glacier, internally accelerating melting. And because a lot of the ground on which the glacier sits is below sea level, it is thought to be particularly vulnerable to melting as warmer water encroaches further under the ice inland……

Ella Gilbert, a research scientist at the University of Reading, said what was happening in the polar regions demanded an urgent response from the international community.

“The polar regions are the canary in the coalmine – they are the symbol of climate change,” said Gilbert, who was a joint author of a recent study warning of the catastrophic impact of global heating on Antarctic ice.

“We really do need to minimise our emissions because if we lose the polar regions, not only are we going to amplify climate change … it will contribute to sea level rise which affects everyone around the globe.” https://www.theguardian.com/environment/2021/apr/30/antarctic-doomsday-glacier-may-be-melting-faster-than-was-thought