Fiber-Optic Cable Reveals Hidden Crevasses that Could Destabilize Glaciers

Fiber-optic cable reveals hidden crevasses that could destabilize glaciers

In recent years, the Alps have experienced devastating glacier collapses: In September 2023, a section of the Marmolada glacier in the Dolomites collapsed, resulting in the deaths of seven mountaineers. Just over a year and a half later, in May 2025, the Birch Glacier above Blatten collapsed, keeping Switzerland and the entire world in suspense.

Fiber-Optic Sensing Uncovers Hidden Crevasses Beneath Glacial Ice

Glaciers may look solid and immovable from a distance, but much of their most important structural damage is hidden beneath the surface. A new study by researchers at ETH Zurich shows that a single fibre-optic cable can map fractures deep inside a glacier with a level of detail that would require hundreds of conventional seismometers. The technique, tested on Switzerland’s Gorner Glacier, revealed that more than eight percent of the ice at the m…