Allalin Glacier
Allalingletscher and Allalinhorn from the East ( 2010)
The Allalingletscher is the largest glacier in the headwaters of the Saas Vispa, in the Pennine Alps, near the southern border of Switzerland. In 1973, he was 6.5 km long with an average width of 1.5 km. Since then, he has retreated by 500 meters in the course of glacier melt. In 2004, an area of 9.68 km ² was determined.
The origins of the Allalingletscher on the glaciated peak of the beam flange ( 4,190 m above sea level. M. ). It flows to the northeast, and finally east along the eastern flank of Rimpfischhorns and the Allalinhorn. To the west of the glacier over the fissured hanging Allalin ( 3'564 m above sea level. M. ) is connected to the Mellichgletscher. The glacier ends with an escape in the upper part of the escarpment north west of the dam of the lake Matt Mark at about 2,700 m above sea level. M. It feeds the Saas Vispa, which brings the water through the Saas Valley to the Rhone.
During the Little Ice Age from the 15th century until the beginning of the 20th century Allalingletscher ranged all the way to the valley of Saas Vispa down and jammed it in what is now Reservoir Matt Mark on a lake. This lake broke out again and again by the glacier wall, which led to some devastating floods in the Saas Valley. Therefore emigrated from many valley dwellers. Alone 1589-1850, the population was affected according to the chronicles of 23 major floods. Only in 1926 the danger was largely dispelled by a tunnel to drain the lake water was driven through the rock on the eastern side of the valley.
A new kind of risk was created when the glaciers retreated from the valley floor and consequently the leading on the steep part of the slope of the glacier lost its stability. During the ice had previously stabilized in the valley of the ice in the flank, hanging over the precipice tongue tends to slipping since then over the smooth plates (see photo). A disaster suddenly occurred on 30 August 1965, when during the construction of Matt Mark dam an ice mass of around half a million cubic meters ( by ETH Zurich two million cubic meters) volume plummeted from Allalingletscher and spilled much of the established at the dam foot Baueinrichtungen. In this case, 88 people were killed.
30-31. July 2000, a similar Eissturz occurred with a volume of about one million cubic meters. The scar was slightly higher than in 1965, damage was no time.
Meanwhile, the tongue is so far melted away, leaving only a little ice depends on the steep flank. If it progresses, the current loss, the glacier will end in a few years above the critical steep slope in a shallow and dangerous tongue.
In its central part, the lower part today, the Allalingletscher united during the Little Ice Age with the Hohlaubgletscher. This smaller glaciers formed below the summit of the Allalinhorn ( 4,027 m above sea level. M. ). The Hohlaubgletscher is separated by the Hohlaubgrat ridge from Allalingletscher.