Ice thickness measurements and volume estimates for glaciers in Norway

Glacier volume and ice thickness distribution are important variables for water resource management in Norway and the assessment of future glacier changes. We present a detailed assessment of thickness distribution and total glacier volume for mainland Norway based on data and modelling. Glacier outlines from a Landsat-derived inventory from 1999 to 2006 covering an area of 2692 +/- 81 km(2) were used as input. We compiled a rich set of ice thickness observations collected over the past 30 years. Altogether, interpolated ice thickness measurements were available for 870 km(2) (32%) of the current glacier area of Norway, with a total ice volume of 134 +/- 23 km(3). Results indicate that mean ice thickness is similar for all larger ice caps, and weakly correlates with their total area. Ice thickness data were used to calibrate a physically based distributed model for estimating the ice thickness of unmeasured glaciers. The results were also used to calibrate volume area scaling relations. The calibrated total volume estimates for all Norwegian glaciers ranged from 257 to 300 km(3).