The Austfonna ice cap is the largest ice mass on the northern archipelago of Svalbard. Glaciers in this area are classified as “near-polar” – such glacier systems are highly sensitive to climate change but are particularly difficult to predict. They are affected by changes in atmospheric temperature and snowfall rate, as well as any changes in the seas into which they flow.
Ice2sea researchers at the University of Oslo have used various satellite and in situ data to measure changes in volume of the Austfonna ice cap for the periods 1983–2007 and 2002–2008. They have found that the interior of the ice cap underwent pronounced thickening during this period, while its margins were thinning at significantly faster rates of over a metre each year. In addition, there was a retreat of floating ice around the margins of the ice cap. Overall, this resulted in a loss of ice, but most of this comes from the loss of ice that was already floating or submarine. This implies that the Austfonna ice cap is currently making only a small contribution to sea-level rise, in sharp contrast to the rest of Svalbard’s glaciers which have contributed significantly to sea-level rise over the last few decades.
This study underlines that the Austfonna ice cap may in some ways need to be treated separately from most other glaciers and ice caps in Svalbard when assessing the overall contribution of the archipelago to sea-level rise.
Ice2sea Work Package: WP3.4
Publication: Moholdt, G., J. O. Hagen, T. Eiken, and T. V. Schule (2010), Geometric changes and mass balance of the Austfonna ice cap, Svalbard, The Cryosphere, 4, 21-34.