A robot keeps an eye on the “Glacier of the Apocalypse”
The four-meter robot Icefin at work.
Scientists have had a close look, for the first time, at the causes of the disappearance of the Thwaites Glacier – which is nicknamed the “Glacier of the Apocalypse” because of its enormous potential for melting and rising sea levels – and the news is both good and bad.
A four-meter, pen-shaped robot that swam under the glacier, exactly where it begins to tower above the sea, has revealed a spot where it is melting so quickly that x27;there's just material flowing from the glacier, said the robot's creator, polar scientist Britney Schmidt of Cornell University.
The Icefin robot during its deployment in Antarctica in January 2020
Scientists had so far been unable to observe this inaccessible, but critically important, portion of the glacier. But by inserting the Icefin robot into a small hole nearly 600 meters long, they saw the crucial role crevasses play in fracturing ice, which hurts the glacier even more than melting.
< p class="e-p">That's how the glacier disintegrates, Schmidt said. It does not thin out or fade away. It's falling apart.
Ms. Schmidt is the lead author of two studies published February 15 in Nature magazine.
< p class="e-p">This fracturing potentially accelerates the progressive disappearance of the glacier, estimated Paul Cutler, the director of the Thwaites program of the National Science Foundation who was on site a few days ago. Its ultimate demise may be due to this disintegration.
This work stems from $67 million in funding from, among others, the United Kingdom and the United States to study the Thwaites glacier, the largest in the world on land and in the sea.
The glacier, which is the size of Florida, is nicknamed the Glacier of the Apocalypse, because sea levels could rise 65 centimeters over several centuries if all the snow and ice in it contains were to melt.
The melting of the glacier is fueled by what happens below, where it is eaten away by warmer water, a process called basal melting, has says Peter Davis, an oceanographer with the British Antarctic Survey, who is the first author of both studies.
Thwaites is a rapidly changing system, much faster than when we started this work five years ago and even when we were there three years ago, said researcher Erin Pettit, of the University of Oregon State, which was not involved in this work. I certainly expect the rapid change to continue and accelerate over the next few years.
Richard Alley, a Pennsylvania State University glaciologist who was also not involved in those studies, said the new work takes an important look at the processes that affect crevasses that could eventually fracture and lead to the loss of most of the glacier.
The good news: Much of the flat underwater area they explored is melting much slower than they anticipated. The bad news: It doesn't change much about the amount of ice lost from the land portion of the glacier and raising sea levels, Davis said.
The melting of the glacier is much less of a problem than its retreat, he added.
“The more the glacier disintegrates and recedes, the more the ice floats on the water. When ice is on land and is part of the glacier, it does not raise sea level. But when it breaks off and falls into the ocean, it contributes by sea level displacement. #x27;water, just like an ice cube placed in a glass raises the level of the liquid it contains.
—Peter Davis, British Antarctic Survey
More bad news: This new information comes from the larger, more stable eastern portion of Thwaites Glacier. Researchers weren't able to land and drill the main portion of the glacier, which is disintegrating much faster. They also found crevices in some corners of the eastern portion, where the disintegration is more pronounced.
To take full measure of the situation, it would be necessary to study the melting of the ice under the main portion of the glacier. But that would require a helicopter rather than an airplane and would be incredibly difficult, said co-author of both studies, researcher Eric Rignot of the University of California, Irvine.
The surface of the main portion of the glacier is so marred by crevasses that they look like sugar cubes. There's nowhere to land a plane, Cutler said.
In addition to melting water and crevices, the little robot filmed several life forms, especially sea anemones, that were swimming under the ice.
It was really cool to accidentally find them in this environment, Schmidt said. We were so tired that we wondered if we really saw what we saw. There were these weird little aliens [anemones] roaming around the interface between the ice and the ocean.
“And in the background were these twinkling little stars that look like rocks and sediment that came from the glacier. And then the anemones. What a fantastic experience!
—Britney Schmidt, Cornell University