Glacier collapse triggers potential flooding in Switzerland - Catastrophic glacier rupture poses flooding risk to Switzerland
In the Swiss canton of Wallis, a section of the Birch Glacier collapsed on Wednesday afternoon, triggering an avalanche that engulfed part of the village of Blatten and destroyed several homes. As of Thursday, a 64-year-old man remains missing.
The danger in the landslide area of Lötschental remains high due to ongoing instability, preventing cleanup operations. "When we can intervene specifically is still uncertain," said local official Jacquod.
Authorities have emptied a reservoir as a precaution to make room for potential floodwaters. The Swiss Army stands ready to provide aid materials. Around three million cubic meters of rock material tumbled into the valley during the glacier collapse, according to the canton's natural hazards chief, Raphaël Mayoraz, creating a formidable barrier in the Lötschental river. This artificial lake is continuously growing.
The collapse had been anticipated for several days. Since Tuesday night, increased activity at the glacier was detected, which intensified throughout the day. The nearby village of Blatten, with approximately 300 residents, had already been evacuated the previous week.
Recent warm temperatures in combination with a large rockfall onto the glacier surface accelerated its instability, causing the collapse and burying parts of Blatten under ice, rock, and mud. Permafrost thawing around the glacier is a contributing factor to the ongoing instability in the affected area.
While some water seepage occurred by May 30, easing immediate flood threats temporarily, forecasted rain for June 2-3 keeps evacuation alerts active, maintaining flood risk concerns. The Lonza river, meandering along the entire length of the debris cone, is currently refilling the Ferden reservoir, which had been emptied as a precaution. However, due to high sediment concentration, normal water turbining operations are suspended. Consequently, the bottom outlet of the reservoir was partially opened to allow controlled water flow.
Despite these measures, the Lötschental valley remains at a high risk of further landslides and flooding due to unstable rock masses and high sediment load in water bodies, with emergency measures and evacuation alerts still in place.
- Community action in the field of environmental science could be crucial to assessing and managing the permafrost thawing around the collapsed Birch Glacier, addressing the ongoing instability in the Lötschental valley.
- In light of the ongoing flood risk concerns in the Lötschental valley, educational programs focusing on weather patterns and climate change could equip residents with the necessary knowledge to prepare for and respond to future environmental disasters.
