The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
Highly mobile boulders are one of the most extraordinary and hazardous landslide phenomena. In recent years, mobile phone footage has captured a number of these events, such as the famous boulder at Mount Elbrus in the Caucasus Mountains. Large earthquakes have also illustrated the impacts of these highly mobile rocks, with a great example being Rocky after the Canterbury earthquakes in New Zealand.
But occasionally a video emerges that still manages to surprise me. A great example has been posted to Instagram by a hiker, Endy Riccio, who was hiking at Chüebodengletscher in Ticino, Switzerland. The landslide is reported to have occurred at 5:42 pm local time on 6 September 2023, apparently in sunny weather:-
The most obvious part of this is the very large boulder that appears early in the video, as shown in this screenshot:-
But note also the smaller but still substantial boulder that bounces much higher, later in the sequence.
This is a great example of the high mobility that can be achieved when boulders have rapid rates of rotation on steep slopes. In these circumstances, bouncing can allow them to travel large distances.
Chüebodengletscher is located at [46.499, 8.448]. The most likely location of the rockslide appears to be as shown below:-
The video demonstrates the risks of being caught in these events. As climate change drives rapid warming in high elevation locations, rock slope collapses are posing an increasing level of risk to alpinists.