30 August 2017
Before and after satellite images of the Pizzo Cengalo rock avalanche
The clean up in the aftermath of the Pizzo Cengalo rock avalanche in Switzerland continues amidst reports of continued small-scale but significant ongoing landslide activity. Swissinfo reports that the search for the eight missing hikers has now been abandoned, whilst the reconstruction phase may take up to three years. The report also includes this slightly intriguing sections:
The landslide is one of the largest to hit Switzerland in the last century. Piz Cengalo had been under observation since 2011, when another – albeit largely unnoticed – landslide caused 1.5 million cubic metres of the mountainside to collapse.
The implication is that the section of slope that had been causing concern remains intact, but I may be misinterpreting what is meant here. I wonder if any readers have further information?
Meanwhile, the site of the landslide continues to be imaged by satellites, and cloud free images from before and after the event (in addition to the image during the collapse, about which I previously posted) are now available. This is a Planet Labs image from 4th August 2017, showing the site of the landslide before the collapse:-
And this image, dated 29th August 2017, shows the aftermath:-
These two images nicely capture both the source of the landslide (i.e. the change is the scar area) and the new landslide deposit. Note that the volume of material that reached the village is quite small compared to the totral landslide volume, but there is now a huge amount of debris stored in the slopes above the settlement. This is the state of the village of Bondo itself:-
It is worth comparing that with this Google Earth image showing the same location in 2010, before the current landslide sequence began:-
Planet Team (2017). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://api.planet.com