Ocean water is pushing miles beneath Antarctica’s “Doomsday Glacier.” This happening is making it more vulnerable to melting than previously considerations, according to new investigations. This new research used radar data from space to perform an X-ray of the crucial glacier.
The World’s Widest Glacier
In West Antarctica, the Thwaites Glacier is the world’s widest glacier and roughly the size of Florida. This nickname, “Doomsday Glacier”, is because of its collapse could cause catastrophic sea level rise. It must be underlined that it’s also Antarctica’s most vulnerable and unstable glacier, in large part because the land on which it sits slopes downward, permitting ocean waters to eat away at its ice.
Thwaites, that already adds 4% to global sea level rise, holds sufficient ice to keep sea levels by more than 2 feet. But because it also is as a natural dam to the surrounding ice in West Antarctica. Many studies have explained to the immense vulnerabilities of Thwaites. Global warming, driven by humans burning fossil fuels, has left it hanging on “by its fingernails,” according to a 2022 study.
A New and Alarming Factor
A group of glaciologists, that is led by scientists from the University of California, employed high resolution satellite radar data to create an X-ray of the glacier. This permitted them to create an image of changes to Thwaites’ “grounding line”. Grounding lines are essential to the stability of ice sheets, and a main point of vulnerability for Thwaites, but have been difficult to study. Eric Rignot, professor of Earth system science at the University of California at Irvine and a co-author on the study explains that “in the past, we had only sporadic data to look at this”, in addition, “in this new data set, which is daily and over several months, we have solid observations of what is going on.”
The “Grounding Zone”
They studied seawater pushing beneath the glacier over many miles, and then moving out again. By the time the water flows in, it’s enough to “raise up” the surface of the glacier by centimetres, Rignot told CNN. He suggested the neologism “grounding zone” may be more apt than grounding line, as it can move nearly 4 miles over a 12-hour tidal cycle.
The speed of the seawater, which moves considerable distances over a not longed time period, increases glacier melt because as soon as the ice melts, freshwater is washed out and replaced with warmer seawater, Rignot commented. In addition, Ted Scambos, a glaciologist at the University of Colorado Boulder, who was not involved in the study, named the research “fascinating and important.”
One big question to be unravelled is whether the rush of seawater beneath Thwaites is a new happening or whether it’s been relevant but unknown for a long time, said James Smith, a marine geologist at the British Antarctic Survey, who was not part of the investigation. Noel Gourmelen, a professor of Earth observation at the University of Edinburgh, commented the use of radar data for this study was interesting. “Ironically it’s by going to space, using our growing satellite capabilities, that we’re learning much more about this environment”. There are still many concepts that are not clear on what the study’s findings mean for the future of Thwaites, said Gourmelen who was not part of the research. It is also no make clear how widespread this process is around Antarctica.
A Government Change
Antarctica as an isolated and complex continent appears to be increasingly vulnerable to the climate crisis. In another study investigators from the British Antarctic Survey looked at the argument for the record low levels of sea ice surrounding Antarctica past year.
Analysing satellite data and using climate models, they have been able to see this record low would have been “extremely unlikely to happen without the influence of climate change.”
Sea ice melting is not a direct effect on the sea level rise because it’s already floating, but it leaves coastal ice sheets and glaciers exposed to waves and warm ocean waters, making them much more vulnerable to melting and breaking up.
The investigators used climate models too, in order to predict the potential speed of recovery from such extreme sea ice loss and found that even after two decades, not all the ice will return. The evidences complete the researched over the last few years that the region is facing a “lasting regime change” too.
