The Jungfrau train stops at the Eigergletscher station. The awed tourists take photos of the mountain panorama. Then the train goes into the seven-kilometer long tunnel up to the Jungfraujoch. What very few of the passengers know is that, to ensure their safety, the most up-to-date technology is being used to monitor the glacier above the station day and night.
It is normal for glaciers to move. The condition of the hanging glacier on the west flank of the Eiger, however, started to become critical in autumn 2015. Glaciologists from ETH noticed that a crevasse was forming behind the front of the glacier, which was separating off an ice lamella as large as about 80 houses with a volume of 80’000 m3. Should the lamella break off, the railway station could be threatened. The Jungfrau railway, which takes about a million passengers a year to the 3453 m a.s.l. summit, reacted immediately and commissioned the SLF to provide an expert assessment of the
hazard situation. Stefan Margreth, Head of the Group ‘Avalanche Protection Measures’, simulated four different scenarios with the computer software RAMMS and determined which measures should be taken. An ice fall is particularly critical if there is a lot of unstable snow below the glacier that could be swept into an ice avalanche. On Stefan’s advice, a radar system has been continuously monitoring the glacier movements since March 2016. Any break-offs can now be detected several days in advance, and the areas at risk closed as a precaution. In winter, an avalanche radar is used in addition. If it records a break-off, the trains can then be stopped in time. (Sara Niedermann, Diagonal 1/17)