Switzerland's largest rock slides [FIGU Zeitzeichen SE 158]

June 16, 2025 - English Source Articles from FIGU Zeitzeichen Sonderausgabe Number 158

Switzerland's largest rock slides: The retreat of the Aletsch Glacier caused two square kilometers of rock to slide away. Six kilometers of hiking trails remain closed to this day. Urs P. Gasche

Red: In light of current events—the "total catastrophe" in Blatten—we recall the massive rock cracks on Riederalp. The article by Urs P. Gasche appeared on June 16, 2016, in "Infosperber." The ground movements on the eastern flank of the Aletsch Glacier were explained by the melting Aletsch Glacier and the resulting reduction in pressure on the mountain slopes, as well as by their thawing permafrost. Riederalp is about twelve kilometers as the crow flies from Blatten. Between them lies the Belalp mountain ridge.

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Even during the "Little Ice Age," which lasted until 1850, the lower part of the Aletsch Glacier was 400 meters high and reached to the tree line. Meanwhile, the glacier on the left edge of the landslide has completely melted, and the ice in the central section will also disappear in the coming years. Since 1850, the average temperature has risen by 1.8 degrees. The consequences of a further temperature rise of 1 to 2 degrees can be estimated. This is explained by Lucienne Rey in the latest issue of the magazine "Umwelt" (Environment) published by the Federal Office for the Environment (FOEN). She quotes Hugo Raetzo from the Landslide Section: "This is a massive landslide with the largest rock displacement in Switzerland." An area of ​​two square kilometers and a rock volume of around 160 million cubic meters are affected. New hiking trails The municipality of Riederalp is busy erecting prohibition signs and fences and developing new hiking trails. The cable car t