Dec. 4 (Bloomberg) — A layer of warmer water under
Antarctica’s ice sheet has been increasing for at least three
decades, possibly due to changed wind patterns linked to climate
change, and may make it melt faster.
That would prompt the oceans to rise faster than expected,
according to an article today in the journal Science.
“We likely are underestimating the sea-level rise that
comes from Antarctica,” said Sunke Schmidtko, one of the
paper’s authors and a researcher at GEOMAR Helmholtz Centre for
Ocean Research Kiel. “This is a process that has been
overlooked so far, that’s not part of most climate models.”
The Antarctic ice sheet is the largest reservoir of frozen
fresh water on the planet. It’s more than 2 kilometers (1.2
miles) thick, on average, enough to raise the level of the
oceans by 60 meters (197 feet) if it melted completely.
Because of differences in salinity, the warmer, saltier
water often flows below a layer of colder, fresh water in the
region.
Schmidtko compared it to a fountain drink. “It’s like if
you have your glass of Coke and all the ice melts, it forms a
fresh layer at the top,” he said.
More warmer water, some of it from as far away as the North
Atlantic, has been accumulating, according to the paper. That’s
likely to accelerate the melting of the ice sheet. While
Schmidtko said it’s not yet clear why that’s happening, the
researchers suspect it’s due to changing wind patterns resulting
from global warming.
Melting glaciers and ice shelves in western Antarctica
already are losing in water weight the equivalent of Mt. Everest
every two years, according to a 21-year analysis by NASA and the
University of California at Irvine released Dec. 2.
To contact the reporter on this story:
Justin Doom in New York at
jdoom1@bloomberg.net
To contact the editors responsible for this story:
Reed Landberg at
landberg@bloomberg.net
Will Wade, Randall Hackley