30 October 2018
Planet Labs imagery of the 11th October 2018 Jomda County rockslide in Tibet
In my post on the 11th October 2018 Jomda County rockslide in Tibet, I noted that I had not been able to track down the precise location. In a comment posted today, Margherita Rocchetti has correctly identified the location using Planet Labs imagery. The correct location is: 31°5’0.00″N 98°42’34.00″E. This location yields the following Planet Labs satellite image of the landslide and the associated impounded water:-
The size of the landslide can be seen in the Planet Labs image below, which includes a scale bar in the lower right corner:-
The landslide from crown to slope toe (i.e. the source length is about 1400 metres long and it is about 700 m wide. There appears to be evidence of super-elevation of the debris up the opposite valley wall, although much of the debris now appears to have been eroded away. There remains some element of blockage of the valley, although the river is flowing, with a substantial volume of water still impounded behind the landslide mass.
There is good Google Earth imagery of the slope that failed, dated 22nd February 2015:-
This appears to show a slope in considerable distress, with deep gullying and signs of tension cracks and deformation at the crown. Zooming in on this area shows a slope that had gone through quite large accumulation of strain:-