'Nothing can stop retreat' of West Antarctic glaciers
Thwaites Glacier is a huge ice stream draining into the Amundsen Bay |
Key glaciers in West Antarctica are in an irreversible retreat, scientists led from the US space agency (Nasa) say.
They analysed 40 years of observations of six big ice streams
draining into the Amundsen Bay and concluded that nothing now can stop
them melting away.Although these are abrupt changes, the timescales involved are likely measured in centuries, the researchers add.
If the glaciers really do disappear, they would add roughly 1.2m to global sea level rise.
The new study has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union, but Nasa held a teleconference on Monday to brief reporters about its findings.
Prof Eric Rignot said warm ocean water was relentlessly eating away at the glaciers' fronts and that the geometry of the sea bed in the area meant that this erosion had now entered a runaway process.
"We present observational evidence that a large section of the West Antarctic Ice Sheet has gone into a state of irreversible retreat; it has passed the point of no return," he explained.
"This retreat will have major consequences for sea level rise worldwide. It will raise sea levels by 1.2m, or 4ft, but its retreat will also influence adjacent sectors of the West Antarctic Ice Sheet which could triple this contribution to sea level."
Jonathan.Amos-INTERNET@bbc.co.uk
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