Brian McDonald
The huge “doomsday glacier“Known for its rapid destabilization, it is experiencing a ‘vigorous ice melt’ that scientists say could alter sea level rise projections.
On a new study, Glaciologists at the University of California, Irvine have discovered that warm, high-pressure ocean water is seeping beneath the Thwaites Glacier in West Antarctica, making it more vulnerable to melting than previously thought. The glacier is about 80 miles in diameter, the widest on Earth. It accumulates so much ice that, if it collapsed completely, it could single-handedly cause global sea levels to rise. by more than two feetaccording to the International Thwaites Glacier Collaboration, which led to its nickname “Doomsday Glacier.”
The findings, published in the Proceedings of the National Academy of Sciences, were used on data collected by scientists from March to June last year. Previously, it was difficult to “figure out what was going on” due to limited and sporadic data, said UC Irvine professor and lead author. Eric Rignot he said. But using satellites, they were able to observe what was happening better than ever before.
“We see seawater coming in at high tide and receding and sometimes rising further below the glacier and getting trapped,” Rignot said.
Eric Rignot/UC Irvine
The sea water is reaching glacier at the base of the ice sheet and flowing through conduits and accumulating in cavities, “creating enough pressure to lift the ice sheet,” Rignot said.
“There are places where the water is almost at the pressure of the overlying ice, so it just takes a little more pressure to push the ice up,” he said. “The water is then compressed enough to lift a column of more than 800 meters of ice.”
As global temperatures continue to warm, this also causes ocean currents to push warmer ocean water toward the coasts of Antarctica, which is saltier and has a lower freezing point. This difference in water is what led to what researchers describe as vigorous melting.
“Thwaites is the most unstable place in Antarctica,” said study co-author Christine Dow, estimating the equivalent sea level rise at 60 centimeters, or about 23.6 inches. “The concern is that we are underestimating the speed at which the glacier is changing, which would be devastating for coastal communities around the world.”
Dow said there is not yet enough information to know how long until the saltwater intrusion is “irreversible,” but that researchers hope the new information will improve existing models and make better predictions “over decades versus centuries.”
“This work will help people adapt to changing ocean levels, while also focusing on reducing carbon emissions to avoid the worst-case scenario.”
