By Liz Kalaugher
Arctic glaciers and ice caps cover an area of 402,000 square km, roughly 55% of the world’s total. But they’re punching above their weight when it comes to sea level rise – although Greenland’s ice sheet is four times larger, it contributes roughly the same amount of melted ice to the world’s oceans. That’s according to Jon Ove Hagen of the University of Oslo, Norway, speaking at the EGU meeting in Vienna.
For example from 2006-2010, around 200 Gigatonnes of ice per year melted from the Greenland ice sheet while the equivalent figure for glaciers and ice caps in the Arctic was 160 Gigatonnes. That said, there is considerable variability around the Arctic region, with some glaciers and ice caps losing mass rapidly and a few growing slightly.
As part of the ice2sea programme, Hagen and colleagues have taken continuous GPS measurements on two fast-flowing outlet glaciers of the Austfonna ice cap in northeastern Svalbard since April 2008. The data indicate that the ice is now moving between two and three times faster than four years ago.
What’s more, around 30-40% of the total ice mass loss is due to calving. Hagen said the ice cap is exhibiting unstable dynamics and the study shows the importance of monitoring calving.