Austdalsbreen on 14th October 2015. Photo: Emma Barfod

Austdalsbreen (61°45'N, 7°20'E) (11.8 km2) is a north-eastern outlet from Jostedalsbreen. The glacier is east facing and ranges in height from 1200 to 1760 m a.s.l. Calving from the 1100 m wide glacier front comprise 10 – 15 % of the annual summer Balance. Austdalsbreen calves into the lake Austdalsvatnet which is regulated between 1150 and 1200 m a.s.l. for hydro-power production purposes. Glaciological work started at Austdalsbreen in 1986 in connection with the construction of the hydro-electric power plant.

Mass balance
Mass balance measurements started in 1988. The average winter accumulation is 4 to 5 meter of snow on the glacier. The mass balance results of Austdalsbreen are published in the series 'Glaciological Investigations in Norway'.

Front posistion change
Before the regulation of Austdalsvatnet and Styggevatnet to a reservoir, a small part of the terminus calved into Austdalsvatnet. After 1988 the glacier has retreated 650 m and the glacier area is reduced by 0.6 km2.

Glacier movement
The velocity and direction of the glacier movement is recorded by repeated surveying of stakes drilled into the glacier surface. Surveying is carried out either by GPS or traditional tachymetry. Close to the terminus the glacier velocity is in the order of 100 m/a, but the velocity varies due to season and lake level. When lake level is high (typical late summer – early winter), the sub-glacial water pressure is relatively high close to the terminus. This reduces sub-glacial friction and increases the glacier sliding velocity. When the lake level is low (typical late winter- early summer) the sub-glacial water pressure is lower, the friction is lower, and the sliding velocity is lower.

Literature

Andreassen, L. M., H. Elvehøy, B. Kjøllmoen, and R. V. Engeset. 2016. Reanalysis of long-term series of glaciological and geodetic mass balance for 10 Norwegian glaciers, The Cryosphere, 10, 535-552, doi:10.5194/tc-10-535-2016. (pdf)

Hooke, R. LeB, Laumann, T.  and Kennett, M.,1989: Austdalsbreen, Norway: Expected reaction to a 40 m increase in water level in the lake into which the glacier calves. Cold Regions Science and Technology, 17, 14 p.

Bjarne Kjøllmoen (Ed.), Liss M. Andreassen, Hallgeir Elvehøy, Miriam Jackson and Rianne H. Giesen, 2011: Glaciological investigations in Norway in 2010. NVE Report 3 2011, 89 p. +app.

Laumann, T. and Wold, B., 1993: Reactions of a calving glacier to large changes in water level. Annals of Glaciology, 16, p 158-162.