Grosser Aletschgletscher

Large ice avalanche from Mönch

The hanging glacier on the south flank of Mönch regularly releases small, and sometimes large ice avalanches which descend on to Jungfraufirn. A particularly large avalanche occured on July 5th, 1982. This event is documented below.

Large ice avalanche from Mönch
Overview: Mönch south flank (upper left), hanging glacier (centre left) and ice avalanche (centre to lower right) as seen from Jungfraujoch (Sphinx). Note route towards Mönchsjochhütte (SAC). The large ice block on the lower right is also shown in the next photo.
Large ice avalanche from Mönch
Largest block of this ice avalanche: height 10 metres, width 15 metres; estimated volume 1000 cubic metres. Ice debris on top of the block shows that it did not rotate during sliding. Firn stratigraphy is visible in the block (photo Peter Müller).
Large ice avalanche from Mönch
Lowermost end of avalanche deposit, looking towards Konkordiaplatz. The largest ice block is at the lower right end of the deposit; the people in the background are on the route towards Mönchsjochhütte (SAC).
Large ice avalanche from Mönch
Large parts of the avalanche descended as relatively compact masses of ice debris and left remarkable tracks. The people on the tracks return from approaching the hanging glacier and are obviously unaware of the danger of further avalanches.
Large ice avalanche from Mönch
Details of the tracks in the orographic right part of the ice avalanche.
Large ice avalanche from Mönch
Aerial photo from the south (see also next photo). This view is also available as a 3D photo.
Large ice avalanche from Mönch
On the lower left, in front of the ice avalanche deposit: looped dog-sledge track, skilift, huts.
Large ice avalanche from Mönch
Map of the avalanche deposit; details in: Download.
Photos 6. and 7. Juli 1984, Jürg Alean. Further details (download) in Zeitschrift für Gletscherkunde und Glazialgeologie.