Night of 1–2 February 1959, on the eastern shoulder of Kholat Syakhl in the northern Urals: nine experienced ski-hikers cut out of their tent into a lethal night and died. For sixty years the case was called unexplained. This panel is runnable: it holds a slab-avalanche force balance — after Gaume & Puzrin (2021) — and proves that a wind-packed slab over a buried weak layer releases once the local slope crosses a critical angle the terrain hides.
source The Dyatlov Pass incident, 1–2 Feb 1959, northern Urals; resolution: J. Gaume & A. M. Puzrin, “Mechanisms of slab avalanche release and impact in the Dyatlov Pass incident,” Communications Earth & Environment 2, 10 (2021). Room: THE WEIRD. The nine dead are treated with respect; rendered, not sensationalised.
Nine members of an Ural Polytechnic ski group camped on an open slope below Kholat Syakhl. Sometime that night all nine cut the tent open from the inside and left, most without boots, into roughly −25 °C and wind. They died on the descent to the treeline; searchers found the abandoned tent on 26 February.
The Soviet inquiry closed on a phrase that outlived it: death by a “compelling natural force.” Into that gap poured sixty years of theories. The record is AMBER — history, honestly held.
Two facts made an avalanche look impossible. First, the tent was not buried — it stood cut and half-standing, no debris cone. Second, some bodies had severe blunt trauma (fractured ribs, a fractured skull) without external wounds — injuries that seemed too violent for snow, yet wrong for a fall.
The measured slope at the tent read gentle, ~15° — below any textbook avalanche angle. So for decades the file said: no slab, no debris, no trigger. The evidence is AMBER; the reading of it was the error.
Gaume & Puzrin (2021) closed it with mechanics. Cutting the tent platform into the slope undercut a wind-loaded slab resting on a buried weak layer; hours later the slab released and slid a short way onto the sleepers — enough for blunt trauma without burial.
The key correction: the local slope under the tent was ~28–30°, not the ~15° the terrain shows — steep enough to fail. Delayed release, small slab, no debris cone. LIT.
Set the slope and the snow. The engine forms the driving shear that gravity pulls down the slope and the resisting shear the weak layer offers, then asks the deciding question: does the slab release?
slab density ρ = 300 kg/m³ (wind-packed); μ = residual friction of the buried weak layer (friction angle ~ arctan μ).
Driving grows with the slope — same slab, rising angle. The slab fails where net crosses zero:
| θ | driving (Pa) | resisting (Pa) | net |
|---|
Critical angle (net = 0): —. At C = 0 it equals arctan μ and is independent of slab depth — a thin slab suffices.
| proposed cause | forces to balance? | stable 15° / fails ~30°? | ok |
|---|
At ~15° the weak layer holds; at the true ~28–30° the driving shear wins and the slab lets go. It slides only a short distance — enough to injure sleepers, not enough to bury the tent. The absence of a debris cone is not a missing clue; it is the small-slab signature.
Why it matters. Each of those — small, late, shallow — is exactly what the 2021 slab model predicts. The very facts once used to rule avalanche out are the fingerprints of this kind of avalanche.
A yeti / menk attack. Dead. A cryptid provides no forces, no tracks, no mechanism — nothing a model can weigh against the injuries or the cut tent.
Infrasound “panic” from Karman vortices. Dead as the cause. It might explain unease, but not the ribs, the skull, or a slab that never buries — it balances no shear.
A secret Soviet weapon test / aliens. Dead. No device, no debris field, no radiation pattern that fits; folklore, not physics.
Standing: a delayed slab avalanche on a locally ~28–30° slope — peer-reviewed, and the only account that balances the forces. LIT
The red move: swap the slab for a fringe cause — yeti, secret weapon, “paradox.” Such a cause offers no driving and no resisting shear, so the engine has nothing to test. A real explanation balances forces; the myth cannot.
Blame the myth and the witness (5) has no force balance to check — it turns red. The fringe theories are DEAD as science; the slab avalanche is LIT.