2 February 2021
Kapuche Lake, Nepal: a video of an avalanche air blast
Posted by Dave Petley
Kapuche Lake, Nepal: a video of an avalanche air blast
Large landslides generate substantial air blasts, which can be extremely damaging. There are some studies of this phenomenon; a classic example was generated by the 2015 earthquake in Nepal, when Langtang was destroyed at least in part by an air blast. The effects were terrible (take a look at the images in that post), but this is an under-researched area.
I don’t normally feature snow avalanches on this blog – there are others who know this topic far better than do I, but there is a very interesting video on Youtube showing an avalanche at Kapuche Lake in Parche, Nepal. This was a very large and very impressive event – the video is worth viewing simply for the scale of the avalanche. The avalanche itself starts at 1 minute 01 seconds:-
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But the really interesting (from my perspective) element of this video is when the avalanche reaches the lake, from about 2 minutes 50 seconds. Stripped of the slope gradient, the avalanche appears to lose energy and indeed it is clear that the group making this video were not concerned. But moments later the air blast reaches them:-
The moment that the air blast arrives at Kapuche Lake in Nepal following an avalanche. Still from a video uploaded to Youtube.
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The initial moments of the air blast are quite dramatic and clearly unexpected. This is followed by a few minutes of intense wind, driven by the mass that has descended from the peak. The event is over in a few minutes.
The intensity of the air blast is notable, but the volume of snow and ice that has descended is small compared with a large rock and ice avalanche. It’s hard to imagine the intensity of an event such as the one at Wenjia in Sichuan Province, triggered by the 2008 Wenchuan earthquake in China.
Dave Petley is the Vice-Chancellor of the University of Hull in the United Kingdom. His blog provides commentary and analysis of landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.
i love it!!!! everything is usually soooo serious!!!!
Some slides cause an airblast, some don’t. What’s the criteria? I looked at your coverage of the 2008 Wenchuan quake and it seems that some huge landslides didn’t have an associated airblast yet smaller ones, like the second slide shown in Beichuan, were strong enough to level that part of town.
Interesting that their fire was not extinguished
I wonder if snow avalanches provide more potential for an air blast. The frictional heating of the avalanche would warm the air, leading it to rise, defusing the force of the blast. The latent heat of melting for snow might provide a mechanism to counteract this.
And through all that, the campfire at the lake’s edge stayed lit!
I’d suggest that the huge cloud of snow has a vast amount of cold, dense air in it. It accelerates as it drops down into the warmer air below it due to increasing difference in density.
I’ve seen the effect on Norwegian fjords when a mass of cold air rolls off the plateau and drops onto the fjord below; it’s like a huge rock hitting the water with the water blast radiating out 360 degrees.
And here’s more details, plus video:
https://www.geographyrealm.com/williwaw-a-colloquial-word-for-katabatic-wind/
And some more details on katabatic winds:
https://www.geographyrealm.com/williwaw-a-colloquial-word-for-katabatic-wind/
This is so cool! I’m sure that the geography of the narrow down-slope valley has something to do with the wind blast! I love how stoked those guys were to witness an earth event such as that! And the rainbow topped it off as a spectacular sight!!
I have experienced the same in 2007 next to Everest base camp. Caught it on video as well. Crazy Video here.
I’m an outdoor videographer on rivers mountains and have to say this guy deserves real credit. He seemed to have a stabilized camera on a monopod. Came prepared and motivated and thus captured the opportunity. Stayed cool under pressure and got us all a tremendous video of something we all will most likely not see in our lifetime. Thanks for sharing this!
Wow! Reminds me of an outdoors Gillette Foaming commercial. Never seen anything like this phenomenon before. Check it out. Quite surreal…
I would imagine alot depends on how narrow and steep, the path of the ravine the avalanche travels down would determine the air blast effect… a large amount of air van be displace by matter moving quickly down a narrow and steep gorge…
I was there any casualties during this event? Anybody got hurt before and after this video?
I beg your pardon for my post before this I’m Sorry I didn’t double check before I posted it.
there was a typo,
I wasn’t there..
Please edit at will
The question is
“Was there any casualty before and after this video was taken? ” Sorry for the trouble, thank you.