Collapse of Florida-sized glacier may happen soon, raising sea levels and threatening coastal cities

Corrections and clarifications: This story has been updated to reflect that if the Thwaites Glacier cracks in the next decade, the rise in sea levels by at least a foot could take decades or centuries to occur.

The Thwaites Glacier in Antarctica, dubbed the "doomsday" glacier, is on the brink of sliding into the ocean as the ice shelf holding it back is showing signs of cracking in the next decade, and scientists say the Florida-sized glacier could raise sea levels by at least a foot in the coming decades or centuries.

In January 2020, scientists said warm water was discovered underneath the Thwaites, which could speed up the melting of the 74,000-square-mile glacier located in West Antarctica. Ice draining from the Thwaites into the Amundsen Sea already accounts for about 4% of global sea-level rise.

But during a meeting with the American Geophysical Union on Monday, scientists say the eastern ice shelf holding the glacier in place has cracks rapidly accelerating that could see it collapse within the next three to five years and spell the beginning of the end of the Thwaites glacier.

"I visualized it somewhat similar to a car window where you have a few cracks that are slowly propagating, and then suddenly you go over a bump in your car and the whole thing just starts to shatter in every direction," Erin Pettit, associate professor of earth, ocean and atmospheric sciences at Oregon State University, said during the press conference. "The collapse of this ice shelf will result in a direct increase in sea-level rise pretty rapidly."

The ice shelf itself wouldn't contribute to rise in global sea levels, but it's not the same for the glacier. The collapse would expose the Thwaites Glacier to ocean water, but the glacier is also suffering from cracks due to the warm water underneath.

When the glacier becomes exposed, the international team of scientists fear the occurrence of ice cliff collapse, when chunks of the glacier exposed to ocean water breaks off into the water. If the glacier were to continue to collapse, it would pose a threat to numerous coastal cities across the world that are already becoming more dangerous to live in due to rising sea levels.

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Ted Scambos, a senior research scientist at the Cooperative Institute for Research in Environmental Sciences, said the glacier is the "the widest glacier in the world," and if it were to collapse, it will also take down other nearby glaciers along with it.

"There's going to be a dramatic change in the front of the glacier probably within less than a decade," Sambos said. "It’s doubled its outflow speed within the last 30 years, and the glacier in its entirety holds enough water to raise sea level by over 2 feet. And it could lead to even more sea-level rise, up to 10 feet, if it draws the surrounding glaciers with it."

Scambos said the glacier could survive on its own, but it will be important to "get a clearer picture of how the glacier will behave" within the next 100 years. But all signs point to the glacier not surviving long.

"The satellite imagery that we've been following, that it's going to essentially bypass that pinning point and start fracturing and falling apart," Pettit said. "It's a little bit unsettling."

Contributing: Doyle Rice, USA TODAY

Follow Jordan Mendoza on Twitter: @jordan_mendoza5.

This article originally appeared on USA TODAY: Antarctic glacier collapse can rapidly raise sea levels in 2031