A robot nicknamed Icefin works under sea ice near McMurdo Station in Antarctica in 2020. The pencil-shaped robot is giving scientists their first look at the forces that are eroding the Thwaites glacier.
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A robot nicknamed Icefin works under sea ice near McMurdo Station in Antarctica in 2020. The pencil-shaped robot is giving scientists their first look at the forces that are eroding the Thwaites glacier.
Schmidt/Lawrence/AP
Scientists have got their first close look at what’s been 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 it. both good news and bad news.
Using a 13-foot pencil-shaped robot that swam below the landing track where the first ice jutted out into the sea, scientists saw a shimmering key point in the Thwaites’ chaotic breakup, “where it melts.” flowing so fast there, just material coming out of the glacier,” said robot creator and polar scientist Britney Schmidt of Cornell University.
Previously, scientists had no observations from this important but inaccessible point on Thwaites. But when a robot called Icefin descended into a slender 1,925-foot (587-meter) hole, they saw the importance of crevices in the ice breaking process, which causes the river the most damage. ice, even more than melting. “That’s how glaciers break up. It doesn’t thin and disappear,” said Schmidt, lead author of one of the two studies. Nature magazine.
Paul Cutler, director of the National Science Foundation’s Thwaites program, who returned from the ice sheet 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.”
Work comes from a large volume A multi-year international research effort worth $50 million to better understand the world’s widest glacier. The Florida-sized glacier has earned the nickname “Doomsday Glacier” because of its amount of ice and the amount of sea water that could rise if it all melted – more than 2 feet (65 cm), although that would be expected to lose goods. a hundred 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. band Erin Pettit of Oregon State University, who was not involved in the study. 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 fissures that can eventually break.” and cause the loss of most of the ice shelf.”
A robot nicknamed Icefin deployed at the Thwaites Glacier in Antarctica in January 2020. Two studies published on Wednesday, February 15, 2023, show that the melting rate is not as fast. concern, but fracturing is causing the most severe consequences for glaciers.
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A robot nicknamed Icefin deployed at the Thwaites Glacier in Antarctica in January 2020. Two studies published on Wednesday, February 15, 2023, show that the melting rate is not as fast. concern, but fracturing is causing the most severe consequences for glaciers.
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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 ice is above ground as part of a glacier, it is not part of sea level rise, but when it separates from 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.
NSF’s Cutler said the main trunk’s glacial surface “has so many crevices that it looks like a collection of sugar pellets. There’s no room for planes to land.”
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 major 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 were so tired that you wondered, ‘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 and sediments and things picked up from glaciers,” says Schmidt. “And then there’s the sea anemone. It’s really a wild experience.”
