Swiss glaciers 1850–2100

Moosfluh starts to slide

When the Aletsch Glacier thinned below a critical level, the valley flank it had been holding up accelerated to 80 cm a day.

Date2016-09-15
Speed before≈ 0.2 cm/day
Speed 2016up to 80 cm/day

The Moosfluh is a deep-seated landslide on the flank of the Great Aletsch Glacier, just below the resort of Riederalp. For decades the slope crept a few millimetres a day.

In autumn 2016 it accelerated dramatically, from about 0.2 cm to as much as 80 cm per day. Researchers tied the acceleration directly to the thinning of the glacier: as the ice at its foot disappeared, it stopped supporting the slope. Geologists call this debuttressing.

Hiking trails were closed and the slope was monitored with radar. The movement slowed after 2017.

Ground movement at Moosfluh measured by the Sentinel-1 satellite, August to November 2016. ESA.
Ground movement at Moosfluh measured by the Sentinel-1 satellite, August to November 2016. ESA. European Space Agency · CC BY-SA 3.0 igo · Wikimedia Commons
The Aletsch Glacier between Hohfluh and Moosfluh, 2017.
The Aletsch Glacier between Hohfluh and Moosfluh, 2017. JoachimKohler-HB · CC BY-SA 4.0 · Wikimedia Commons

Glaciers

Sources

Sources

  1. Kos et al. (2016). Contemporary glacier retreat triggers a rapid landslide response, Great Aletsch Glacier. Geophysical Research Letters. agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL071708
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