A surge in temperature from 2003 has eased the brakes on Greenland’s Zachariae ice stream.
Jim Yungel/NASA’s Wallops Flight Facility, file photo
The last edge of the Greenland ice sheet that resisted global warming has now become unstable, adding billions of tonnes of meltwater to rising seas, scientists have said.
In a study published in the journal Nature Climate Change, researchers said a surge in temperature from 2003 had eased the brakes on a long “river” of ice that flows to the coast in north-eastern Greenland.
Known as an ice stream, the “river” takes ice from a vast basin and slowly shifts it to the sea – in the same way that the Amazon River drains water.
In the past, the flow from this ice stream had been constrained by massive build-ups of ice debris choking its mouth.
But a three-year spell of exceptionally high temperatures removed this blockage and, like a cork removed from a bottle, helped accelerate the flow, the study said.
The ice stream, called Zachariae, is the largest drain from an ice basin that covers a whopping 16 per cent of the Greenland ice sheet.