Rockslope Hazards
Rockslope Hazards
 
 
 

We quantify the stability state of rock and soil slopes and investigate how they respond to triggering factors.

Our goal is to develop and implement techniques to forecast scenarios,  provide early warning of potential disasters and where possible, provide cost effective mtiigation.

 
 

The Moosfluh Rock Slope Instability
The Moosfluh is located the valley flank overlooking the Great Aletsch glacier. The glacier has been undergoing rapid retreat, and as a consequence, several rock slope instabilities are responding to those rapid changes with increasing activity (e.g. DSF and MSF landslides indicated in the accompanying landslide distribution map (right).

We’ve been studying interactions between glacier retreat and rock slope instability since 2008 – our findings have relevance for all mountainous regions undergoing deglaciation, most likely as a result of climate change.

You can read several highlights of our work below or follow this external link for more detailed information in our 2016 scientific article published in Geophysical Research Letters.

 
 

The most important outcome of our investigations on the response of the Moosfluh rock slope response to glacier retreat is shown in the accompanying figure (right).

For the first time, we quantified the relationship between the lowering of glacier ice (e.g. height reduction) and the acceleration of a landslide response. We also identified and documented a key indicator of impending large scale failure – an increase in rockfall & local landslide activity.

 
 

The Piz Cengalo Rock slope Instability
The Piz Cengalo rock slope instability failed catastrophically on 23 August, 2017. During the period 2012-2017 terrasense was monitoring the rock slope using terrestrial radar interferometry as part of an AlpArge project.

 
 

A timely early warning…

Based on time series displacement maps from the period 2012 to 2017, we identified that the rock slope underwent a transition from a sub-critical to critical stability state. Several weeks prior to the catastrophic failure, an early warning was issued to local authorities and appropriate safety measures were put in place.

Following the rock avalanche event of August 23, terrasense was contracted by the Canton Graub√ľnden (AfWN), in collaboration with Bonanomi Ltd to measure and interpret the stability status of the rock slope. Our inputs played a central role in decision-making during the post-crisis intervention by local authorities.

 
 

Run out zone of the 3.5 Mill m3 rock avalanche.