thwaites

The doomsday glacier

October 9, 2024 By EarthWise Leave a Comment

The Thwaites Glacier is an enormous Antarctic Glacier. Its area is larger than that of Florida – in fact, larger than 30 other U.S. states – and it is melting. It has been retreating for 80 years but has accelerated its pace in the past 30. Its shedding of ice into the ocean already contributes 4% of global sea level rise. If it collapsed entirely, it would raise sea levels by more than 2 feet. For this reason, it has been dubbed the Doomsday Glacier.

A team of scientists has been studying it since 2018 in order to better understand what is happening within the glacier. They sent a torpedo-shaped robot to the glacier’s grounding line, which is the point at which the ice rises up from the seabed and starts to float. The underside of Thwaites is insulated by a thin layer of cold water. However, at the grounding line, tidal action is pumping warmer sea water at high pressure as far as six miles under the ice. This is disrupting the insulating layer and is speeding up the retreat of the glacier.

The potential collapse of the glacier is not even the only massive risk it poses. It also acts like a cork, holding back the vast Antarctic ice sheet. If that ice sheet were ever to collapse, sea levels could rise 10 feet.

A critical unanswered question is whether the ultimate collapse of Thwaites Glacier is already irreversible. There are regular heavy snowfalls that occur in the Antarctic which help replenish ice loss. Whether nations’ progress in slowing climate change can change the balance between ice accumulation and ice loss on the glacier remains to be seen.

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Web Links

‘Doomsday’ glacier set to melt faster and swell seas as world heats up, say scientists

Photo, posted January 3, 2022, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Threat From Thwaites | Earth Wise

January 20, 2022 By EarthWise Leave a Comment

The Thwaites Glacier in Antarctica is the widest glacier in the world. It is about 80 miles across and in places extends to a depth of about 2,600 to 3,900 feet. The glacier is roughly the size of Florida, and it currently contributes 4% of annual global sea level rise as it continues to retreat from a warming ocean.

The International Thwaites Glacier Collaboration is a team of nearly 100 scientists dedicated to studying the glacier. According to the scientists, Thwaites has doubled its outflow speed within the last 30 years. The glacier in its entirety holds enough water to raise global sea levels by over two feet, which would be catastrophic.

A third of the glacier flows more slowly than the rest because it is braced by a floating ice shelf that is held in place by an underwater mountain. The concern is that the brace of ice slowing the glacier may not last for long.

Beneath the surface, warmer ocean water is attacking the glacier from all angles. The water is melting the ice directly beneath the glacier causing it to lose its grip on the underwater mountain. Massive fractures have formed and are growing.

Warm water is also a threat for what is called the grounding zone, which is the area where the glacier lifts off the seabed. There are many possible scenarios under which there could be a major ice loss from the glacier. It is unclear how quickly it could occur. It might take decades, or it could be centuries. The threat is large enough and real enough that continued observation and research is essential.

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Web Links

The Threat from Thwaites: The Retreat of Antarctica’s Riskiest Glacier

Photo, posted October 16, 2012, courtesy of J. Yungel / NASA Ice via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.