Variations of Grosser Aletschgletscher

Grosser Aletschgletscher - the largest glacier in the Alps - is by tradition a dominating research field of Swiss glaciologist and our laboratory in particular. Long-term glacier observation have been carried out to document glacier variations:

• Since the 1880's the length changes at the glacier tongue were recorded annually
• Starting in September 1918, the firn accumulation and mass balance was measured on Jungfraufirn. These are the second longest time series of in-situ stake measurements

Special high precision topographic maps covering the whole catchment area of the branched glacier system have been produced repeatedly in 1926/27 and 1957. The mass balance of the whole catchment area is evaluated with the hydrological method since the hydrological year 1922/23.

In an ongoing project the length, area, volume, and mass changes are continuously observed applying modern remote sensing techniques as well as direct field measurements. In order to calculate net volume changes of high spatial resolution, photogrammetrical results from two sets of recent aerial photographs for 1980 and 1999 were compared with the topograhical maps. The changes in mass on Jungfraufirn are continuously measured twice per year in spring after the accumulation season and in late summer after the ablation season. The variation of snow accumulation and melting is recorded monthly. Part of these investigations contribute to the Swiss Glacier Monitoring Network.

Collaboration:

Dr. Guillaume Jouvet (Institute of Mathematics, Freie Universität Berlin)

Dr. Matthias Huss (Université de Fribourg)

Results from numerical simulations of Grosser Aletschgletscher