The Ice in Antarctica Has Melted Before

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Sixty per cent of the world’s fresh water is bound up in Antarctic ice sheets. 

Sixty per cent of the world’s fresh water is bound up in Antarctic ice sheets. Thirty million cubic kilometres of ice is perhaps a difficult number to grasp. But if absolutely all Antarctica’s ice melted, the seas would rise by 58 metres on average.

“The ice sheet in East Antarctica stores enormous amounts of water. This means that this is the biggest possible source of future sea level rise – up to 53 meters if all of the East Antarctic ice melts – and is seen as the largest source of uncertainties in the future sea level adaptation planning,” says Irina Rogozhina, an associate professor at the Department of Geography at NTNU.

Most melting/ice loss in Antarctica happens through ocean-driven melting of ice shelves and ice calving. This, in turn, leads to an acceleration of ice streams on land and a greater discharge of ice into the ocean, where it gets lost to melting/calving, she said.

This was also likely the cause of larger ice loss during warmer periods of the past. In Greenland, these two processes contribute to about 65% of all ice loss.

Read more at Norwegian University of Science and Technology

Image: Collecting stones on Månesigden mountain, in Heimefrontfjella, Queen Maud Land. The polished surface of the stone shows that is has been covered by an ice layer. The researchers analysed the stone for cosmogenic isotopes that can tell them how long it has been since the stone was covered by ice. Carl (Calle) Lundberg is taking notes while PhD student Jenny Newall collects samples. (Credit: Photo: Ola Fredin, NTNU)