The unstoppable loss

Aerial photograph of the Aletsch glacier in Swiss canton Valais

The mountain ridge alongside the Aletsch Glacier in Swiss canton Wallis provides visitors with a dramatic view of the ice, as it snakes its way back into the mountains. These days, those who ascend to the top of the Moosfluh cable car are presented with a mixed view of forest, scree and ice, but three hundred years ago, the landscape was much different. The massive ice sheets were growing and the Fiesch glacier even began threatening to engulf an adjacent village.

Since the beginning of the industrial age around 1850, the alpine glaciers have lost around a third of their area and over half of their overall mass. In recent years, the reduction has accelerated to the point where the glacier – which is nearly two kilometres wide, 900 metres deep (at the deepest point, Konkordiaplatz) and 23 kilometres long – drops by twenty centimetres on a hot summer’s day. An unimaginable amount of ice being lost, and statistics which show that the glacier will cease to exist by the end of this century at the latest. The retreat of the ice is also causing other effects: the loss of support from the ice is causing the aforementioned ridge, on the southern side of the valley, to collapse in extremely slow motion.

The Härdernagrat above Riederalp is slowly starting to destabilize

As the glacier retreats, small landslides have been observed in the valley where two geological plates meet. The moving landscape has been a challenge for developers. The Moosfluh cable car, which opened in December 2015, was built with an innovative design that takes into account rock movements of 11 metres horizontal to the northwest and 9 metres vertical in the next 25 years.

Swissinfo, 2016