26 February 2019
Two interesting new landslide videos from the Himalayas
Heavy rainfall and snow over the Himalayas in recent days has triggered extensive landslides, with many roads being blocked. A couple of videos have emerged showing landslide events, both of which are quite interesting. The first for which there is little information, reportedly occurred in the Sainj Valley. It appears to show a debris flow passing across a road, with a trapped pick up truck. The vehicle is eventually lost to the flow:-
The flow is quite interesting in terms of a constant flow of fairly coarse sediment, although the flow rate appears to increase with time:-
The second video is an unusual collapse in a slope that combines weathered bedrock and a large unweathered block, which is undermined by the ongoing failure:-
The sequence of images below shows the evolution of movement of the large unweathered block, which starts by sliding, with a strong element of ploughing of the debris down slope, before the block starts to topple forward, at which point it rapidly fragments:-
The video shows the complex movement mechanisms of this types of slide. Interestingly, it is very unlikely that this would have been evident from the landslide scar and debris pile, which illustrates the challenges of back analysis of landslides without evidence of the morphology of the slope before the failure occurred.
Meanwhile, there has been a number of landslides in the US in recent days, including this example from WV-112, Ingleside Road in West Virginia:-
This will take some effort to clear.