The type of material present under glaciers has a big impact on how fast they slide towards the ocean.
The type of material present under glaciers has a big impact on how fast they slide towards the ocean. Scientists face a challenging task to acquire data of this under-ice landscape, let alone how to represent it accurately in models of future sea-level rise. “Choosing the wrong equations for the under-ice landscape can have the same effect on the predicted contribution to sea-level rise as a warming of several degrees,” says Henning Åkesson, who led a new published study on Petermann Glacier in Greenland.
Glaciers and ice sheets around the world currently lose more than 700,000 Olympic swimming pools of water every day. Glaciers form by the transformation of snow into ice, which is later melted by the atmosphere in summer, or slides all the way into the sea. With climate change, glaciers are breaking up and drop icebergs into the ocean at an accelerating pace. Exactly how fast depends to a large extent on the bed below all the ice. Glaciers conceal a landscape under the ice covered by rocks, sediments and water. A new study shows that the way we represent this under-ice landscape in computer models means a great deal for our predictions of future sea-level rise. More specifically, how we incorporate the friction between the ground and the ice sliding over it in glacier models is what affects our predictions. This was found by a team of Swedish and American scientists, when they simulated the future of Petermann Glacier, the largest and fastest glacier in northern Greenland.
Read more at Stockholm University
Image: Henning Åkesson (Credit: Henning Åkesson)