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I don't think I've seen a snuff film of that scale before. I'm not good with even fictional horror. This may haunt my dreams. For most of the people there was j

I don't think I've seen a snuff film of that scale before. I'm not good with even fictional horror. This may haunt my dreams. For most of the people there was just nothing they could do. But others would have had a chance if they had run perpendicular to the flow and climbed like their life depended on it. I'll try to remember that the next time I'm fleeing in panic from a flash flood. Looks like a warning siren could have saved some lives. But apparently this was a black swan.

markdown 2mo ago
I think the Japan tsunami videos showed as many, but it was spread out over the course of almost 2hrs and happened in slow motion over a large area. You could see some cars speeding to safety while others were washed away. Some stayed in taller structures assuming they were safe and were slowly washed away.
ghastmaster 1mo ago
Perpendicular is not the scientifically best path. 45 degree angle is the best angle if the threat is moving toward you at the same velocity that you can move. As the velocity of the threat increases, the angle gets closer to perpendicular. The size of the threat and distance of course matter as well. I think about this before tree felling. In chainsaw classes they teach you to move at a 45.
- dreamcompiler 1mo ago
  Likewise if your car stalls on a railroad crossing, run at a 45 degree angle toward the train. This puts you away from the path of flying debris.
- Reason077 1mo ago
  Looking at the footage, the water/avalanche was moving far faster than anyone could move on foot. Well over 100 km/h, I would estimate.
  - dgellow 1mo ago
    And taking the entire infrastructure with it, including buildings and roads
    - dredmorbius 1mo ago
      Scrubbed bare from what I've seen to date of post-incident footage, though that's still preliminary.
ANH 1mo ago
| But apparently this was a black swan. What is your definition of black swan? This paper is from 2022 and scientists have been warning about climate change for decades. It's not like this possibility wasn't anticipated. It seems likely we'll see more glacial events as the atmosphere warms.
- throwup238 1mo ago
  There have been maybe three such events in the 21st century (glacier or landslides producing more than a magnitude 5 quake), and none of them have happened in an area like the Himalayas. The other two were in Alaska on Mt Steller in 2005 and the Lamplugh Glacier in 2016, neither of which produced massive downstream floods. It usually takes entire icebergs calving off to produce such seismic events and intense monsoons to create such flooding.
  - ElProlactin 1mo ago
    > There have been maybe three such events in the 21st century It seems that past history (especially recent) will not be a good predictor of future events.
    - throwup238 1mo ago
      Spoiler alert: that’s the whole point of a black swan event.
      - ElProlactin 1mo ago
        A black swan event is an event that is unpredictable because it is so rare. While I'd wait for confirmation about the cause of this specific incident, the point you seem to be ignoring is that, due to climate change, events that would have been considered "black swans" historically will become more and more common, to the point that they are expected to occur.
        throwup238 1mo ago
suzzer99 1mo ago
I wonder if the river went dry first, like the water receding off into the horizon before a tsunami?
- ghastmaster 1mo ago
  It is possible if you consider madaxe_again's theory(comment here). If the debris just started descending without interruption, there would be no receding.
  - suzzer99 1mo ago
    Well supposedly it was caused by a landslide blocking the river for a few minutes, then the dam burst all at once.
- dredmorbius 1mo ago
  Based on video footage which has emerged, no.
colechristensen 1mo ago
The great flood myths across the world are quite possibly ancestral memories of this kind of flood on a continental scale. Retreating ice age glaciers would make lakes the size of states held at bay by an impromptu dam of various kinds of debris (or more glacier) which then would break dumping great lake amounts of water hundreds of miles into the ocean within days. This kind of thing probably happened in lots of places.
- delichon 1mo ago
  You just pushed me into a rabbit hole called the Zanclean megaflood. https://en.wikipedia.org/wiki/Zanclean_flood https://en.wikipedia.org/wiki/Zanclean_flood
- hommelix 1mo ago
  It is supposed that such an event happened, when the land between continental Europe and England got flooded. This was as well during a warmer period when glacier melted. And there was human population on that land. https://en.wikipedia.org/wiki/Doggerland https://en.wikipedia.org/wiki/Doggerland
  - colechristensen 1mo ago
    Oh there's geological evidence of these things happening in the pacific northwest, the waves and water scouring the landscape in an unimaginable fashion left evidence to be seen today. Like 1000 Niagra falls for a month straight. Outflows measured in billions of gallons per second or 10+ cubic kilometers per hour. https://en.wikipedia.org/wiki/Channeled_Scablands https://en.wikipedia.org/wiki/Channeled_Scablands
- GolfPopper 1mo ago
  The Missoula Floods in the northwestern US were a similar sort of event, though I'm not sure how the scale compares. https://en.wikipedia.org/wiki/Missoula_floods https://en.wikipedia.org/wiki/Missoula_floods
  - 1mo ago
scheme271 1mo ago
There was another similar flood on the same river about a year or two ago. The problem was the the glacial flooding started in Tibet and affected people just over the border (one of the videos is from the border crossing). There's no international data sharing for this sort of thing between China and Nepal and Nepal can't deploy sensors in Tibet to give sufficient warning.
21asdffdsa12 1mo ago
We have tsunami warnings all the times now. Nobody is stopping people from burying sensor posts upstream.
regularfry 1mo ago
I suspect you are dramatically overestimating how fast humans can climb. I hope I'm wrong.
dredmorbius 1mo ago
From further information that's emerged: - The site captured in the video, the Gyirong Port border crossing between China and Nepal, was struck by the flood roughly seven minutes after the presumed avalanche thought to have triggered the event. - Flood inundation is seen up to 800 m (2,600 ft) above river level, and the camera position in the video at approximately 20--25m (roughly 6--8 stories) above ground level was engaged in the debris flow. - It would take a fit person 4--8 minutes to climb even 250m or so above ground level, presuming instant notification and a clear evacuation path. Even with an instant warning of upstream conditions survival was overwhelmingly unlikely. - Subsequent footage appears to show complete obliteration off all structures, with no trace remaining. This is based on preliminary imagery, without precise location information, and in a landscape changed beyond all recognition. - Astoundingly, two survivors from the Port are mentioned in Wikipedia presently. Though yes, one of the peculiarities of flood risk is that elevation equals safety. That's modulo a number of other factors though. In particular, with an event of this magnitude, wind blast is a major effect. Toward the end of one video a line of buses in a car park is seen shifting backward, I suspect due to wind. These can reach well above hurricane force, and of course carries its own debris and threats, where even grass and straw can penetrate deeply. There's also the risk of secondary landslides and the like in steep terrain. One of the regions affected by this event has an etymology from "mud wall", which may be a reference to the geology of the canyon walls themselves. Those could easily be unstable. Best option is to be lucky and not be there when things go horribly wrong.

markdown 2mo ago

I think the Japan tsunami videos showed as many, but it was spread out over the course of almost 2hrs and happened in slow motion over a large area. You could see some cars speeding to safety while others were washed away. Some stayed in taller structures assuming they were safe and were slowly washed away.

ghastmaster 1mo ago

Perpendicular is not the scientifically best path. 45 degree angle is the best angle if the threat is moving toward you at the same velocity that you can move. As the velocity of the threat increases, the angle gets closer to perpendicular. The size of the threat and distance of course matter as well. I think about this before tree felling. In chainsaw classes they teach you to move at a 45.

dreamcompiler 1mo ago
Likewise if your car stalls on a railroad crossing, run at a 45 degree angle toward the train. This puts you away from the path of flying debris.
Reason077 1mo ago
Looking at the footage, the water/avalanche was moving far faster than anyone could move on foot. Well over 100 km/h, I would estimate.
- dgellow 1mo ago
  And taking the entire infrastructure with it, including buildings and roads
  - dredmorbius 1mo ago
    Scrubbed bare from what I've seen to date of post-incident footage, though that's still preliminary.

ANH 1mo ago

| But apparently this was a black swan. What is your definition of black swan? This paper is from 2022 and scientists have been warning about climate change for decades. It's not like this possibility wasn't anticipated. It seems likely we'll see more glacial events as the atmosphere warms.

throwup238 1mo ago
There have been maybe three such events in the 21st century (glacier or landslides producing more than a magnitude 5 quake), and none of them have happened in an area like the Himalayas. The other two were in Alaska on Mt Steller in 2005 and the Lamplugh Glacier in 2016, neither of which produced massive downstream floods. It usually takes entire icebergs calving off to produce such seismic events and intense monsoons to create such flooding.
- ElProlactin 1mo ago
  > There have been maybe three such events in the 21st century It seems that past history (especially recent) will not be a good predictor of future events.
  - throwup238 1mo ago
    Spoiler alert: that’s the whole point of a black swan event.
    - ElProlactin 1mo ago
      A black swan event is an event that is unpredictable because it is so rare. While I'd wait for confirmation about the cause of this specific incident, the point you seem to be ignoring is that, due to climate change, events that would have been considered "black swans" historically will become more and more common, to the point that they are expected to occur.
      - throwup238 1mo ago

suzzer99 1mo ago

I wonder if the river went dry first, like the water receding off into the horizon before a tsunami?

ghastmaster 1mo ago
It is possible if you consider madaxe_again's theory(comment here). If the debris just started descending without interruption, there would be no receding.
- suzzer99 1mo ago
  Well supposedly it was caused by a landslide blocking the river for a few minutes, then the dam burst all at once.
dredmorbius 1mo ago
Based on video footage which has emerged, no.

colechristensen 1mo ago

The great flood myths across the world are quite possibly ancestral memories of this kind of flood on a continental scale. Retreating ice age glaciers would make lakes the size of states held at bay by an impromptu dam of various kinds of debris (or more glacier) which then would break dumping great lake amounts of water hundreds of miles into the ocean within days. This kind of thing probably happened in lots of places.

delichon 1mo ago
You just pushed me into a rabbit hole called the Zanclean megaflood. https://en.wikipedia.org/wiki/Zanclean_flood https://en.wikipedia.org/wiki/Zanclean_flood
hommelix 1mo ago
It is supposed that such an event happened, when the land between continental Europe and England got flooded. This was as well during a warmer period when glacier melted. And there was human population on that land. https://en.wikipedia.org/wiki/Doggerland https://en.wikipedia.org/wiki/Doggerland
- colechristensen 1mo ago
  Oh there's geological evidence of these things happening in the pacific northwest, the waves and water scouring the landscape in an unimaginable fashion left evidence to be seen today. Like 1000 Niagra falls for a month straight. Outflows measured in billions of gallons per second or 10+ cubic kilometers per hour. https://en.wikipedia.org/wiki/Channeled_Scablands https://en.wikipedia.org/wiki/Channeled_Scablands
GolfPopper 1mo ago
The Missoula Floods in the northwestern US were a similar sort of event, though I'm not sure how the scale compares. https://en.wikipedia.org/wiki/Missoula_floods https://en.wikipedia.org/wiki/Missoula_floods
- 1mo ago

scheme271 1mo ago

There was another similar flood on the same river about a year or two ago. The problem was the the glacial flooding started in Tibet and affected people just over the border (one of the videos is from the border crossing). There's no international data sharing for this sort of thing between China and Nepal and Nepal can't deploy sensors in Tibet to give sufficient warning.

21asdffdsa12 1mo ago

We have tsunami warnings all the times now. Nobody is stopping people from burying sensor posts upstream.

regularfry 1mo ago

I suspect you are dramatically overestimating how fast humans can climb. I hope I'm wrong.

dredmorbius 1mo ago

From further information that's emerged: - The site captured in the video, the Gyirong Port border crossing between China and Nepal, was struck by the flood roughly seven minutes after the presumed avalanche thought to have triggered the event. - Flood inundation is seen up to 800 m (2,600 ft) above river level, and the camera position in the video at approximately 20--25m (roughly 6--8 stories) above ground level was engaged in the debris flow. - It would take a fit person 4--8 minutes to climb even 250m or so above ground level, presuming instant notification and a clear evacuation path. Even with an instant warning of upstream conditions survival was overwhelmingly unlikely. - Subsequent footage appears to show complete obliteration off all structures, with no trace remaining. This is based on preliminary imagery, without precise location information, and in a landscape changed beyond all recognition. - Astoundingly, two survivors from the Port are mentioned in Wikipedia presently. Though yes, one of the peculiarities of flood risk is that elevation equals safety. That's modulo a number of other factors though. In particular, with an event of this magnitude, wind blast is a major effect. Toward the end of one video a line of buses in a car park is seen shifting backward, I suspect due to wind. These can reach well above hurricane force, and of course carries its own debris and threats, where even grass and straw can penetrate deeply. There's also the risk of secondary landslides and the like in steep terrain. One of the regions affected by this event has an etymology from "mud wall", which may be a reference to the geology of the canyon walls themselves. Those could easily be unstable. Best option is to be lucky and not be there when things go horribly wrong.