A confluence of warm water threatens to knock down the pillars that keep the “Doomsday Glacier” afloat.
Early measurements below the icy tongue of the Thwaites Glacier in Antarctica have now revealed an underestimated flow of warm water from the east.
This heat input mixes with other water below the glacier and invades several critical “fixing points,” the researchers say, reducing them on all sides.
If activity continues or, worse, accelerates, the team is worried that it could ultimately release massive amounts of ground ice flowing into Pine Island Bay from the seabed.
The Thwaites Glacier has been nicknamed the Doomsday Glacier because it is very large (it is 192,000 square miles, is slightly smaller than the state of Kansas in the United States) and is melting at a disturbing rate. As a result, the future of the West Antarctic ice sheet remains the only major point of uncertainty for sea level rise.
Due to the remote location of the glacier and the dangerous conditions in the region, only a few measurements have been taken at the edge of the ice shelf and so far it had not been taken towards the lower cavity.
“The good news is that we are now collecting for the first time data that is needed to model the dynamics of the Thwaite Glacier,” says physical oceanographer Anna Wåhlin of the University of Gothenburg in Sweden.
“These data will help us better calculate ice melting in the future. With the help of new technology, we can improve models and reduce the great uncertainty that now prevails over global sea level variations.”
The information was collected by a submersible vehicle called Ran, which swam deep under thick ice to measure the strength, temperature, salinity, and oxygen content of the underlying ocean currents.
The trip was more successful than scientists expected, but the results were not as promising.
At this time, the Thwaites Glacier accounts for about 10 percent of the current sea level rise, but as warm, saltwater tends to converge below, the ice shelf has the potential to contribute very, very much. more as the planet warms. Like removing a cork from a bottle of wine, the loss of this ice shelf could cause even more ice from the earth to melt and flow into the ocean.
In the end, the researchers identified three warm water inlets, one of which we had been seriously underestimating. Deep-water flows from the east were thought to be blocked by a nearby underwater ridge, but new data from Ran suggest that these deep currents are still being found toward the bay.
“The channels for accessing warm water and attacking Thwaites were not known to us before the investigation,” says geological oceanographer Alastair Graham of the University of South Florida.
“Using sonar on the ship, nestled with very high-resolution ocean maps from Ran, we were able to check that there are different paths that water enters and leaves the ice platform cavity, influenced by the geometry of the ocean floor.” .
Ultimately, this means that warm, salt water enters the cavity under the Thwaites ice shelf from both sides of its main fixation point to the north, possibly destabilizing the entire structure.
It is not yet clear how much of this available heat actually contributes to melting this main fixation point, but the authors predict that the energy carried by a single local current is sufficient to melt the previous ice at a rate of more than 86,000 kilograms ( approximately 95 tons) per year.
This equates to the total fundamental mass of the entire Thwaites ice shelf between 2010 and 2018, indicating that these warm entries are likely to affect the melting pattern of the entire system.
“This fixation point is one of the last features that reinforces the upstream ice flow, and satellite observations indicate that its extent has declined in recent decades,” the authors write.
World Day of Misfortune might come sooner than we thought.
The study was published in Scientific advances.