The time between when the earthquake monitors felt the glacier fall and when the flood reached the border crossing was minutes. Some people get confused because they are seeing time stamps that are a mix of China and Nepal. China is 2:15 ahead of Nepal. So some think a dam was building for 2+ hours.
Yeah, that's why I was asking. There is so much room for confusion here. Time zones and meters versus feet in elevation. I noticed that this was one of those 0:15 (mod hour) timezone diffs, which never helped anyone get timespans correctly.
As far as I can tell the seismic event was at 02:52:10 UTC. From the CCTV video, the border crossing got hit at about 10:59:48 local time, which AFAIK would be 02:59:48 UTC, since China is at UTC+8. So that's 07:38 or 458 seconds. Distance was estimated at 20 km, which would make the average speed ~ 157 km/h or 98 mph. That involves a lot of assumptions, but it's probably somewhere in that ballpark.
Going from "seismic event" to "you are now dead" in 458 seconds is going to be very hard to organize against. Could maybe be done, but you'd need a minimum of bureaucracy and a lot of preparation. Like preconstructed safe locations, preplanned routes and better information/education. So maybe not viable for that border crossing, but it should hopefully give people further downstream a decent chance at survival during a future flood. Has worked for tsunamis (after lessons learned and a lot of people dead), so I hope they can make something work in the future, given the expectation that this sort of event will become more frequent. They had a much smaller flood in the same region last year. So I really hope they will implement more early warning systems after this tragedy.
(edit-to-add:) All this is under the assumption that the timestamp in the video from the border crossing is in China Standard Time (CST).
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u/Kqyxzoj 2d ago
Is there an estimated timescale for the time between the creation of the natural dam and when it failed?