10 May 2017
Geiranger Fjord in Norway: the spectacular rockslide video
The accompanying text states merely that:
“My school went on a Mountain trip when suddenly we heard loud noises. We SAW big blocks of rocks falling down into the Fjord and were amazed by it!”
NRK has an article (in Norwegian) that provides a little more detail, noting that the slide generated a displacement wave about 1 metre high that damaged some docks at Geiranger. The event was registered on the national seismic monitoring network across Norway, suggesting that the volume was not insignificant:
There are a couple of interesting elements to this rockslide. The first is the timing – yet again we see a major rockslide occurring in the spring, again without an obvious trigger in terms of a seismic event or heavy rainfall. This is not unusual, and of course it may be associated with now and ice melt as temperatures rise after the winter.
Second, the video shows the mobility of a small proportion of the blocks that have detached in the Geiranger Fjord event. Take a look at this still from the video:
Note the splashes a considerably ahead of the main landslide dust cloud, which presumably mark the impact on the water of individual blocks. Only a small proportion of the blocks travel this far, but they are a nice illustration of the extreme end of the mobility distribution.
Major rockslides are of course nothing new in Norway, and not far from this site is the Akernes landslide, which is considered to be a significant hazard that is closely monitored.