It’s actually nicknamed the “doomsday” glacier because of what could happen if it began to rapidly add water to the ocean. In a study published in the journal Nature Geoscience, researchers suggest the massive ice sheet could begin melting twice as fast as in the past.
To make their projections, the scientists studied the glacier’s movements over the last few decades. By studying tracks on the seabed, researchers were able to measure how far the ice has traveled over the last 100 years.
While the giant block of ice appears to be moving faster than in the recent past, suggesting a higher melt rate, it’s melted even faster in the past. The scientists determined that the glacier was shrinking at over 1.3 miles per year a century ago. That’s nearly twice as fast as it moved in the period from 2011 to 2019.
“Understanding the recent history of Thwaites Glacier, and the processes controlling its ongoing retreat, is key to projecting Antarctic contributions to future sea-level rise,” the study’s authors wrote. “Of particular concern is how the glacier grounding zone might evolve over coming decades where it is stabilized by sea-floor bathymetric highs.”
Faster sea level rises
The concern, of course, is how a faster melt might affect sea levels. The glacier is about the size of the state of Florida. Should it completely fall into the sea – something that isn’t expected to happen within this decade – scientists believe it could raise sea levels by up to two feet.
By way of comparison, the North American ice sheet that covered all of Canada and the Northern U.S. during the ice age, melted fairly rapidly at the end of the last ice age with extreme increases in sea level. According to Scientific American, sea level in some places had increased by 30 feet within a few hundred years, “more than if the ice sheet that still covers Greenland were to melt today.”
Anna Wåhlin, a professor of physical oceanography at Sweden’s Gothenburg University, says there are a lot of different scenarios that could play out for the Thwaites Glacier, not all of them bad.
"Exactly how big a threat there is is unfortunately still difficult to answer, but the fact that we finally have a data point that the models can tie back to is an important part of the puzzle," Wåhlin told NBC News.