Study: If this glacier melts, Florida would be flooded 1:44
(CNN) --
Antarctica's "Doomsday Glacier," nicknamed so because its collapse could trigger a catastrophic rise in sea levels, is unexpectedly melting rapidly, new research warns.
Thwaites Glacier is about the size of Florida and is located in West Antarctica.
Part of what holds it in place is an ice shelf that juts out of the ocean surface.
The platform acts like a cork, holding the glacier on land and providing an important defense against rising sea levels.
But the ice shelf is very vulnerable to rising ocean temperatures.
In two studies published Wednesday in the academic journal Nature, scientists reveal that while the rate of melting under most of the ice shelf is slower than previously thought, deep cracks and formations in "ladder" on the ice are melting much faster.
Cracks in Thwaites Glacier in 2020. Credit: Dr. Britney Schmidt/ITGC
As climate change accelerates, Thwaites Glacier is changing rapidly.
Every year it dumps billions of tons of ice into the ocean, contributing 4% to the annual rise in sea level.
Melting is especially rapid where the glacier meets the seafloor, which has receded nearly 14 kilometers since the late 1990s, exposing more of the ice to the relatively warm ocean waters.
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The complete collapse of Thwaites could cause a rise in sea levels of more than 70 centimeters, which would be enough to devastate coastal communities around the world.
But Thwaites also acts as a natural dam for the surrounding ice in West Antarctica, and scientists have estimated that global sea level could ultimately rise by around 3 meters if it collapsed.
Although it could take hundreds or thousands of years, the ice shelf could disintegrate much sooner, triggering an unstable and potentially irreversible glacier retreat.
To better understand the redevelopment of the remote coastline, a team of American and British scientists from the International Thwaites Glacier Collaboration traveled to the glacier in late 2019.
Using a hot water drill, they drilled a hole nearly 2,000 feet deep in the ice and, over a period of five days, sent out various instruments to take measurements of the glacier.
Drilling on the Thwaites Glacier.
Credit: Peter Davis/British Antarctic Survey/ITGC
The instruments included a torpedo-shaped robot called the Icefin, which allowed them to access areas that were previously almost impossible to explore.
The remote-controlled vehicle took images and recorded information on the temperature and salinity of the water, as well as ocean currents.
Britney Schmidt, an associate professor at Cornell University and lead author on one of the papers, told CNN that the rover was able to "swim up to these really dynamic places and take data from the seafloor to the ice."
The results of the survey reveal "a very nuanced and complex picture," Peter Davis, an oceanographer with the British Antarctic Survey and lead author of the other paper, told CNN.
The Thwaites Glacier in Antarctica, also known as the "End of the World Glacier" due to the enormous risk that its melting poses to global sea level.
Credit: NASA/OIB/Jeremy Harbeck
The scientists found that although the glacier is receding, the rate of melting under most of the flat part of the ice shelf was slower than expected.
According to the study, the average rate of melting was between 2 and 5.4 meters per year, less than expected in previous models.
According to the study, the melting is being suppressed by a layer of cooler, fresher water at the base of the glacier, between the ice shelf and the ocean.
"The glacier continues to have problems," Davis said in a statement, adding: "What we have found is that despite small amounts of melt, the glacier is still retreating rapidly, so it does not appear to take much to unbalance it."
The Icefin robot under the sea ice near McMurdo Station.
Credit: Rob Robbins/ITGC
Icefin in the Kamb Ice Stream after being lifted from the water.
Credit: Britney Schmidt/Justin D. Lawrence/ITGC
The scientists were also surprised by a second finding.
They discovered a far more complex underwater glacial landscape than expected, dominated by bizarre, stair-like terraces and crevasses (large fissures that run through the entire ice shelf).
The research team discovered that the melting was especially rapid in these areas.
Warm, salty water seeped into cracks and fissures and widened them, contributing to the instability of the glacier.
"The glacier is melting not only from above, but also from the outside," Schmidt said.
Melt along the sloping ice of crevasses and stairways "may become the primary trigger for ice shelf collapse," according to the study authors.
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The findings add a new layer to a series of alarming studies that point to rapid melting of the glacier.
According to a 2021 study, the ice shelf could break up in the next five years, and last year scientists claimed that Thwaites Glacier is "on edge" as the planet warms, with the possibility of a rapid retreat in the next years.
"We knew that these glaciers were changing. We knew that it was related to the temperature of the ocean. We knew that they were melting. We knew that the atmosphere was warming. And we knew that the glaciers were melting," Schmidt said.
What the latest research does is provide "the missing pieces" to find out exactly how this change is taking place, he said.
Icefin camp on Thwaites Glacier in 2020. Credit: Daniel Dichek/ITGC
Icefin deployment on Thwaites Glacier in January 2020. Credit: Daniel Dichek/ITGC
David Rounce, a Carnegie Mellon University glaciologist who was not involved in the study, told CNN the new research offered "new insights into how quickly the bottom of the ice shelf is melting and the mechanisms by which it is melting." is melting, which are very important for improving our understanding and ability to model how Thwaites will change in the future."
Davis said the research can help make more accurate projections of sea level rise, which can fuel efforts to mitigate climate change and protect coastal communities.
From a more personal perspective, she said, he also hopes it will prompt people "to sit up and take notice of the changes that are taking place."
"Despite its remoteness, the consequences of what happens in Thwaites will affect the whole world," Davis said.
melting of glaciers
