Investigation of changes in Briksdalsbreen, western Norway from 1966 - 2020

Abstract

Briksdalsbreen in western Norway was studied using remote sensing. Sets of optical aerial photographs captured between 1966 to 2020 were used with LiDAR-based Digital Elevation Models (DEMs) and glacier outlines derived from satellite images to estimate the changes in length, area, surface elevation and mass balance of the glacier. The results show that Briksdalsbreen retreated a total of ~ 450 m and shrunk by 0.25 Km2 (0.04 % a-1) between 1966 and 2020; however, it advanced between 1966 to 2001 before it retreated between 2001 – 2010. The glacier fronts thickened by less than ~ 0.5 m during the period of advancement in the late 90s but the total glacier thinned by ~ 3 m in the whole period of 54 years (1966 – 2020). The estimated mass balance is -0.045 m w. e. a-1 for Briksdalsbreen between 1966 and 2020 and -0.246 m w. e. a-1 for the period of 2010 – 2020. The result of the length estimate from this study agrees with field observation and the surface elevation change found for 2010 - 2020 conforms with the results from regional remote sensing investigation. However, the lack of published mass balance data for Briksdalsbreen and high uncertainty in comparing the mass balance of glaciers limited a comparative assessment of the estimated mass balance. Nevertheless, this study confirms that Briksdalsbreen is retreating rapidly and losing mass like many other glaciers in Norway. It also identifies increased summer temperature as the driving force of the glacier retreat since early 2000, although high winter precipitation had early caused its expansion between 1966 to 2001. The study demonstrates that remote sensing is a useful tool in glacier change assessment.