Scientists claim that the infamous Doomsday Glacier is in peril after discovering unexpected formations beneath the ice shelf.
According to new research, the “Doomsday Glacier” in Antarctica, so named because its collapse could result in a catastrophic rise in sea level, is melting quickly and in unexpected ways.
In West Antarctica, there is a glacier called the Thwaites Glacier that is about the size of Florida. An ice shelf that protrudes onto the ocean’s surface helps to keep it in place. The shelf functions as a cork, keeping the glacier from moving farther inland and offering a crucial barrier against sea level rise. But as the water warms, the vital ice shelf is extremely vulnerable.
While the rate of melting beneath much of the ice shelf is slower than previously believed, deep fissures and “staircase” forms in the ice are melting significantly faster, according to two studies that were published in the journal Nature on Wednesday. The Thwaites Glacier is undergoing fast change as global warming intensifies.
It contributes around 4% of the annual rise in sea level by releasing billions of tonnes of ice into the ocean each year. When a bigger portion of ice is exposed to relatively warm ocean water, melting occurs more quickly at the glacier’s junction with the seafloor, which has receded nearly nine miles (14 kilometres) since the late 1990s.
Sea levels might rise by more than two feet (70 centimetres) as a result of the entire collapse of the Thwaites, which would be sufficient to obliterate coastal settlements all around the world. However, the Thwaites is also acting as a natural dam to the surrounding ice in West Antarctica, and scientists have calculated that if the Thwaites collapsed, the global sea level might ultimately rise by about 10 feet.
While it might take hundreds or thousands of years, the ice shelf could collapse considerably sooner, leading to an unstable and possibly irreversible glacier retreat. A group of US and British researchers from the International Thwaites Glacier Collaboration visited the glacier in late 2019 to learn more about how the remote shoreline is changing.
They drilled a hole roughly 2,000 feet (600 metres) deep into the ice using a hot water drill, and over the course of five days, sent down several sensors to collect data from the glacier. A robot resembling a torpedo dubbed Icefin was among the tools that gave them access to previously inaccessible surveying terrain. The remotely controlled vehicle captured photographs and collected data on ocean currents, water temperature, and salinity.
According to lead author of one of the studies and associate professor at Cornell University Britney Schmidt, it was able to “swim up to these highly dynamic regions and capture data from the sea floor all the way to the ice.” Oceanographer Peter Davis, who is a main author on the other publication and works for the British Antarctic Survey, told CNN that the research’s findings paint “a really nuanced and complex picture.”
The rate of melting beneath a large portion of the flat area of the ice shelf was lower than anticipated, the scientists discovered, despite the glacier’s retreat. The study found that the actual melt rate was lower than what earlier models had predicted, averaging 2 to 5.4 metres annually.
According to the study, a layer of fresher, colder water between the ice shelf and the ocean is preventing melting from occurring at the base of the glacier. “The glacier is still in peril,” Davis said in a statement, adding, “What we have found is that even little levels of melting there is still rapid glacial retreat, so it seems that it doesn’t take a much to drive the glacier out of balance.”
The scientists were taken aback by a second discovery as well. They found an underwater glacial environment that was far more complicated than they had anticipated, with unusual terraces that resembled staircases and crevasses, which are large fractures that run the whole length of the ice shelf. The research team discovered that melting happened exceptionally fast in some places. Cracks and crevasses could funnel warm, salty water through, widening them and causing instability in the glacier.
Schmidt said that the glacier was also “melting out” in addition to melting up. According to the research’ authors, melting along the sloped ice of the fractures and terraces “may become the key trigger for ice shelf collapse.” The findings add a fresh dimension to a cascade of frightening studies pointing to the glacier’s rapid melting.
The Thwaites Glacier is clinging on “by its fingernails” as the world heats, with the possibility of a dramatic retreat in the following years, according to a 2021 study that concluded the ice shelf might break within the next five years.
“We knew these glaciers were changing. We were aware of the connection to ocean temperature. We were aware of the melting. We were aware of the warming of the atmosphere. And we were aware that the glaciers were disintegrating, added Schmidt.
The most recent research fills in “the missing bits” needed to determine precisely how this transition is taking place, according to her. When asked about the new research, Carnegie Mellon University glaciologist David Rounce said it provided “novel insights into how rapidly the bottom of the ice shelf is melting and the mechanisms by which it’s melting, which are very important for improving our understanding and ability to model how Thwaites will change in the future.”
According to Davis, the study can contribute to the development of more precise sea level rise estimates, which will be used to inform efforts to lessen climate change and safeguard coastal populations. He added that he also hoped it would cause people to “sit up and take notice of the changes that are occurring” from a more personal perspective.
Despite being so far away, Davis asserted that everyone would be affected by what occurs on Thwaites.