The watchword for glaciers: Stay cool!
Summer has arrived, causing not only us to sweat but the alpine glaciers too. Every year a further melting back, or sweating, of the glaciers in Switzerland can be measured. On the Gemsstock, at the Gurschen Glacier, this meltdown has been fought against in recent years. The main line of defence is a special fleece that is placed as a covering over part of the glacier each spring.
At the end of each ski season, snow from Gurschenalp is bulldozed up onto the glacier – a technique known as “snow farming.” This gives the glacier a first layer of insulation, which keeps it cool for months. Afterwards, heavy fleece rolls are transported out of winter storage at Gurschen onto the Gemsstock and laid as a covering over the glacier. Applying these felt sheets is hard work. A team of eight to ten men work on the steep slopes to cover about a hectare of the glacier. The weather is a critical factor when laying this blanket. The air must be absolutely still and it must be dry, otherwise the sheets cannot be physically managed. They are anchored to the glacier at the upper end with steel cable and additionally ballasted with sandbags.
As part of a scientific study, the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of the Swiss Federal Institute of Technology (ETH) is monitoring this “wrapping art” on the Andermatt glacier. The intermediate findings are encouraging. The blanket indeed works, preventing further melting of the ice in the sunshine. Only 30 centimetres of the glacier mass melts beneath the blanket. In contrast, on an unprotected test area the ETH researchers measured a full 150 centimetres of melt.
The blanket will be removed again in time for next winter. Before too much snow falls, the protective sheets will be rolled up and flown by helicopter to winter storage at Gurschenalp. The fleece sheets will be dried as well as possible in preparation for their next application on the glacier a good half year later.
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