Natural and societal consequences of climate-forced changes of Jostedalsbreen Ice Cap
Jostedalsbreen shrinks by more than 1 km2 per year according to new inventory
by Jacob Yde, December 2, 2022
A new study maps the extent of all glaciers and ice-marginal lakes in Norway, including the outlet glaciers of Jostedalsbreen and the ice-marginal lakes along the periphery of the ice cap. The area of Jostedalsbreen is 458.1 km2 (2019) and diminishes by more than 1 km2 per year at the moment.
According to a new study published in Journal of Glaciology by Liss M. Andreassen, Teodor Nagy and Bjarne Kjøllmoen (Norwegian Water Resources and Energy Directorate) and Joshua Leigh (University of Durham), the area of Jostedalsbreen has reduced from 473.8 km2 in the previous survey conducted in 2006 to 458.1 km2 in 2019. Some smaller glacier areas have been detached from Jostedalsbreen since 2006. If they are included, the comparable glacier area in 2019 is 459.7 km2. This is an area loss of approximately 14.0 km2, or 3% of the glacier area in 2006.
Jostedalsbreen is by far the largest glacier complex in Norway followed by Vestre Svartisen (190.2 km2 in 2018), Søndre Folgefonna (153.8 km2 in 2019), Østre Svartisen (125.1 km2 in 2018) and Blåmannsisen (80.8 km2 in 2018).
Sentinel-2 satellite images of August 27, 2019 were used to map Jostedalsbreen (Copernicus data, 2019).
All of these glaciers have lost more relative glacier area (in % of previous mapping) than Jostedalsbreen. The authors have used satellite imagery from Sentinel-2 to map glacier outlines and ice-marginal lakes in 2018 and 2019. The results were evaluated against high-resolution aerial photographs and satellite images from Pléiades. The new areas of glaciers and ice-marginal lakes were then compared with areas in the previous inventory.
Tuftebreen is one of the outlet glaciers from Jostedalsbreen, which has been retreating since the previous glacier inventory (photo: J. Aasen, NVE, September 2019).
The results from the new inventory are also summarized in Norwegian in the NVE publication: “Breer og fonner i Norge”.