Doomsday Glacier: Robot findings under Thwaites in Antarctica

WASHINGTON — Scientists get a close-up look for the first time at what is eating away at part of Antarctica’s Thwaites ice shelf, nicknamed the Doomsday Glacier for its ability to melt and rise in sea levels, and That’s good news as well as bad news.

Using a 13-foot pencil-shaped robot that swam below the landing track where the ice first jutted out into the sea, scientists saw a shimmering key point in the Thwaites’ chaotic breakup, “where it melts.” flowing too fast there, only material flowing away from the surface. glacier,” said roboticist and polar scientist Britney Schmidt of Cornell University.

Previously, scientists had no observations from this important but inaccessible point on Thwaites. But when the robot called Icefin descended into a slender 1,925-foot-tall hole, they saw the importance of the crevices in the ice fracturing process, which does the most damage to glaciers, even more than melting. run. “That’s how glaciers disintegrate. It does not thin and disappear. It broke,” said Schmidt, lead author of one of the two studies in the journal Nature on Wednesday.

Paul Cutler, director of the National Science Foundation’s Thwaites program, who returned from the iceberg last week, said the faulting “has the potential to hasten the overall collapse of that ice shelf. “The final failure mode may be due to collapse.”

This work is the result of a massive $50 million international research effort over several years to better understand the world’s widest glacier. This Florida-sized glacier is nicknamed the “Doomsday Glacier” because of its ice volume and possible sea level rise if it all melts — more than 2 feet (65 cm), though that is expected to take hundreds of years.

Peter Davis, an oceanographer at the British Antarctic Survey and lead author of one of the studies, said the Thwaites’ melting was driven by what was happening below, where the water was warmer. bottom gnawing, something called fundamental melting.

“Thwaites is a rapidly changing system, changing much faster than when we started this work five years ago and even since we entered the field three years ago,” the researcher said. tape Erin Pettit of Oregon State University said. learn. “I certainly expect rapid change to continue and accelerate over the next few years.”

Penn State University glaciologist Richard Alley, who was also not involved in the study, said the new work “gives us an important insight into the processes that influence cracks that can eventually rupture.” and cause the loss of most of the ice shelf.”

Good news: Much of the flat underwater they discovered is melting much more slowly than expected. Bad news: That doesn’t really change how much ice is leaving the inland part of the glacier and pushing up sea levels, Davis said.

Davis said melting is not nearly the problem at Thwaites but glacier retreat. The more the glacier breaks up or recedes, the more ice is floating in the water. When the ice is above ground as part of a glacier, it is not part of sea level rise, but when it separates from the land and then enters the water, it increases the overall water level by shifting move, just as ice added to a cup of water will rise to the water level.

And one more bad news: This is from the east, the larger and more stable part of the Thwaites. The researchers couldn’t safely land a plane and drill a hole in the ice in the main fuselage, which was breaking apart much faster. And they also found stairs like stairs, those crevices, in the more stable parts of the east, where the fall was much faster and much worse.

The key to knowing exactly how bad conditions are on the glacier will require going to the main trunk and observing the melt from below. But that would require a helicopter to land on ice instead of a heavier plane and would be extremely difficult, said study co-author Eric Rignot of the University of California Irvine.

The main trunk’s glacial surface is “cluttered with fissures, almost like a collection of sugar cubes. There’s nowhere to land the plane,” said NSF’s Cutler.

Ted Scambos of the National Snow and Ice Data Center, who was not involved in the study, said the results help further understand how Thwaites are declining.

“Unfortunately, this will still be a big problem a century from now,” Scambos said in an email. “But our better understanding gives us time to act to slow the rate of sea level rise.”

As the skinny robot weaves its way through the hole in the ice – created by a jet of hot water – the cameras show more than just melted water, important fissures and the seabed. It shows creatures, especially sea anemones, swimming under the ice.

“It’s really cool to find them here in this environment by chance,” Schmidt said in an interview. “We’re so tired that you have to wonder, ‘am I really seeing what I’m seeing?’ You know because there are scary aliens (anemones) roaming the ice-ocean interface.

“In the background like all these twinkling stars like rocks, sediments and things picked up from glaciers,” says Schmidt. “And then there is anemones. It was truly a wild experience.”