Scientists have detected new cracks in the key ice shelf that buttresses Antarctica’s Thwaites Glacier, indicating that the ice shelf could break apart within the next three to five years.
The Thwaites Glacier, about the size of Florida, is known as the “doomsday glacier,” due to the possibility that it may already be well past a tipping point into a virtually unstoppable, runaway melt, according to Science News.
The glacier spans about 80 miles (120 kilometers) and extends to a depth of about 2,600 to 3,900 feet (800 to 1,200 meters) at its grounding line — where the glacier transitions from a land-attached ice mass to a floating ice shelf in the Amundsen Sea.
And as Ted Scambos, a glaciologist at the Boulder, Colorado-based Cooperative Institute for Research in Environmental Sciences, told reporters, if the whole thing were to fall into the ocean, it would raise sea levels by 65 centimeters, or more than two feet. Right now, its melting is responsible for about 4 percent of global sea-level rise.
“And it could lead to even more sea-level rise, up to 10 feet [3 meters], if it draws the surrounding glaciers with it,” Scambos said in a statement, referring to the weakening effect that one ice shelf collapse can have on other nearby glaciers.
To explain what has been happening with the ice shelf, scientists held a virtual press briefing on Monday at the American Geophysical Union’s fall meeting in New Orleans, Louisiana.
In plain language, warming ocean water is not just melting Thwaites from below; it’s also loosening the glacier’s grip on the submerged seamount below, making it even more unstable.
As the glacier weakens, it then becomes more prone to surface fractures that could spread until the entire ice shelf shatters “like a car window” — and that could happen as soon as three years from now, the scientists said.
If this floating ice shelf breaks apart, the Thwaites Glacier will accelerate and its contribution to sea-level rise will increase by as much as 25 percent, according to the report.
The Thwaites Glacier is situated in a deep basin, so if it collapses, neighboring glaciers would follow, and over the next few centuries, it could lead to the loss of the entire West Antarctic Ice Sheet, contributing to a large rise in sea levels, according to Science.
“That would be a global change,” Robert DeConto, a glaciologist at the University of Massachusetts, Amherst said. “Our coastlines will look different from space.”
