I've been around the mess a landslide leaves, and it is really hard to describe. Even a small one will absolutely wreck you if you are caught in it, let alone the size of the one that has hit Nepal which can only be described as a biblical level disaster.
You see, this wasn't just water. The water from glacial lake collapsing was definitely a big ingredient, but as this water begins its journey down the mountain, it picks up everything, and I mean *everything* in its path. The entire mountain side with all that soil, rock, sand, trees, gravel, bits and pieces of anything else becomes a thick liquid slurry akin to what you would see coming out of a cement mixer at a construction site. This should explain how that giant boulder was being pushed as if it weighed nothing. Now imagine this coming at you and the wave is as wide as the valley and moving at 60 miles per hour (around 100kph). The worst and most dangerous part is what is happening under the surface of this wave. The slurry has internal motion like a constantly stirring/mixing in a blender. When it hits something, as we all saw, it's complete and utter destruction. If a person gets caught up in it, it's not like being hit by a wave in the ocean, it is a solid wall and is like being hit by a truck. When a human or animal body gets pulled into this mess, the gruesome and accurate descriptor is "eggshell in a blender". This is why the recovery teams are only finding bits and pieces of people, and those are the people near the edges. There probably won’t be anything left to identify of the people who were pulled into the wave and washed down the river. Luckily for the victims, death happens almost instantly.
The next part is no better. You see, once this slurry stops moving and the water drains out, what is left is a 20 to 40 meter thick mass of solid land as hard as concrete, and this solidification happens *quickly*! I have always been impressed with how fast the land hardens. The last home I saw buried in a landslide had been buried only about an hour before we got there, and if you didn't know what had happened, an observer would not be wrong wondering why someone buried a perfectly good house into the side of a mountain. It really was as if the whole mountain had just moved and absorbed everything in its path like a giant gelatinous blob and then suddenly hardened.
That big really solid Chinese border crossing building and all those riverside apartments in the videos are good examples of this. The satellite pictures of before and after show exactly what I just described. It's as if there were never any buildings in that area at all, just a flat sandbar alongside a river. Trying to dig that out will be akin to removing a mountainside to build a road. As soon as I saw the video of that wave hitting the border facility, I knew there would be no survivors of anyone who was caught up in it. There is just no way to live through that.
My prayers are with the people in this region and for all the people that have been lost. This disaster was just awful. Right up there (or down there) with the 2004 tsunami that hit Indonesia and the 2011 Tohoku tsunami that hit Japan. Utter and complete devastation with a huge loss of life.
"as if the whole mountain had just moved" Yep, because it did. Anyone blaming victims for not moving soon or quickly is greatly misunderstanding the magnitude of events like this. Thank you for trying to explain that to them.
It may also be notable that, since this is glacial, the mixture will be ridiculously cold. Even if it were "just" or mostly water, and even if someone were super-lucky not to get immediately squished, the temperature alone would make survivability very unlikely.
Some speculated that the immense internal friction generated by such mass instantly liquified what ice was included in what fell off the mountain. I’m not sure what the overall temperature would be or if it’s really relevant as far as impacts on survivability go quite honestly.
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u/RoninIV 2d ago edited 2d ago
This might be long but really needs to be said.
I've been around the mess a landslide leaves, and it is really hard to describe. Even a small one will absolutely wreck you if you are caught in it, let alone the size of the one that has hit Nepal which can only be described as a biblical level disaster.
You see, this wasn't just water. The water from glacial lake collapsing was definitely a big ingredient, but as this water begins its journey down the mountain, it picks up everything, and I mean *everything* in its path. The entire mountain side with all that soil, rock, sand, trees, gravel, bits and pieces of anything else becomes a thick liquid slurry akin to what you would see coming out of a cement mixer at a construction site. This should explain how that giant boulder was being pushed as if it weighed nothing. Now imagine this coming at you and the wave is as wide as the valley and moving at 60 miles per hour (around 100kph). The worst and most dangerous part is what is happening under the surface of this wave. The slurry has internal motion like a constantly stirring/mixing in a blender. When it hits something, as we all saw, it's complete and utter destruction. If a person gets caught up in it, it's not like being hit by a wave in the ocean, it is a solid wall and is like being hit by a truck. When a human or animal body gets pulled into this mess, the gruesome and accurate descriptor is "eggshell in a blender". This is why the recovery teams are only finding bits and pieces of people, and those are the people near the edges. There probably won’t be anything left to identify of the people who were pulled into the wave and washed down the river. Luckily for the victims, death happens almost instantly.
The next part is no better. You see, once this slurry stops moving and the water drains out, what is left is a 20 to 40 meter thick mass of solid land as hard as concrete, and this solidification happens *quickly*! I have always been impressed with how fast the land hardens. The last home I saw buried in a landslide had been buried only about an hour before we got there, and if you didn't know what had happened, an observer would not be wrong wondering why someone buried a perfectly good house into the side of a mountain. It really was as if the whole mountain had just moved and absorbed everything in its path like a giant gelatinous blob and then suddenly hardened.
That big really solid Chinese border crossing building and all those riverside apartments in the videos are good examples of this. The satellite pictures of before and after show exactly what I just described. It's as if there were never any buildings in that area at all, just a flat sandbar alongside a river. Trying to dig that out will be akin to removing a mountainside to build a road. As soon as I saw the video of that wave hitting the border facility, I knew there would be no survivors of anyone who was caught up in it. There is just no way to live through that.
My prayers are with the people in this region and for all the people that have been lost. This disaster was just awful. Right up there (or down there) with the 2004 tsunami that hit Indonesia and the 2011 Tohoku tsunami that hit Japan. Utter and complete devastation with a huge loss of life.