Glacial variations on a meso-scale: examples from glaciers in the Aurland Mountains, southern Norway

Abstract

Mass-balance measurements carried out since 1963 on six glaciers in southern Norway indicate that glaciers to the west of the main water divide have increased their mass, whereas glaciers further east have decreased. However, when small glaciers within the same mountain area are studied, the picture is more complicated. Different exposures, the terrain forms on the upwind side and area distribution of the glaciers are important factors with regard to the effect of the wind-driven snow. The three glaciers studied in this paper are located within a 10 km radius in the Aurland Mountains, but differ in size, exposure and dynamic condition. Volume changes were calculated from two repeated mappings of two glaciers. Svartavassbreen increased in volume in all areas; Storskavlen decreased over most of its area and increased in some parts. Vargebreen has lost nearly all its ice mass in the eastern part, but has changed little in the western part. It is concluded that the volume changes found on these glaciers mainly reflect changes in local snow accumulation. Analysis of air-pressure data from the period 1952–94 is presented and supports the hypothesis that there has been a change to stronger westerly winds from the mid-1960s onwards. It is recommended that glaciers chosen for long-term studies of volume changes should represent different exposures. The topography of the surrounding terrain is also important.