{
  "id": "dyatlov-pass-1959",
  "title": "Dyatlov Pass: testing the avalanche reconstruction",
  "country": "Russia",
  "category": "autre",
  "date": "1959-02-01",
  "date_label": "Night of 1–2 February 1959",
  "location": "Northern Urals, Dyatlov Pass area",
  "lat": 61.75,
  "lng": 59.45,
  "location_precision": "region",
  "location_note": "Regional orientation marker near the pass; not a precise tent position or a location of human remains.",
  "summary": "Nine hikers died in the northern Urals. This dossier examines what modern snow modelling can explain, which assumptions it needs and why a plausible reconstruction is not a recording of the event.",
  "verdict": "A physically supported avalanche explanation exists; the complete historical sequence remains uncertain.",
  "sources": [
    {
      "id": "D1",
      "title": "Gaume and Puzrin (2021): slab avalanche release and impact",
      "url": "https://www.nature.com/articles/s43247-020-00081-8",
      "kind": "Research article · open access",
      "language": "en",
      "note": "Analytical and numerical models of a proposed sequence; includes methods and supplementary material."
    },
    {
      "id": "D2",
      "title": "2021 research paper — PDF",
      "url": "https://www.nature.com/articles/s43247-020-00081-8.pdf",
      "kind": "PDF · same study",
      "language": "en",
      "note": "Reading copy of D1, not an independent source."
    },
    {
      "id": "D3",
      "title": "Gaume and Puzrin (2022): follow-up expeditions",
      "url": "https://www.nature.com/articles/s43247-022-00393-x",
      "kind": "Research follow-up · open access",
      "language": "en",
      "note": "Reports subsequent field observations bearing on avalanche feasibility."
    },
    {
      "id": "D4",
      "title": "2022 follow-up — PDF",
      "url": "https://www.nature.com/articles/s43247-022-00393-x.pdf",
      "kind": "PDF · same follow-up",
      "language": "en",
      "note": "Reading copy of D3; later field evidence is not an observation of the 1959 night."
    }
  ],
  "sections": [
    {
      "title": "Incident brief",
      "text": "The case concerns the deaths of nine hikers after their camp was established on a snowy slope in the northern Urals in February 1959. A 2021 study investigates whether a relatively small slab avalanche could have been released after a delay and caused severe injuries. Its proposed mechanism combines a cut in the slope, wind-driven accumulation and slab failure. The paper’s contribution is a physical feasibility argument, not the discovery of a film or instrument record of the accident.",
      "refs": [
        "D1"
      ]
    },
    {
      "title": "What later fieldwork changes",
      "text": "The 2022 follow-up describes expeditions and observations of avalanches in the area. This weakens an absolute claim that slab avalanches cannot happen there. It cannot establish the precise loading, snow structure or timing on the night of the deaths. A regional possibility and a historical attribution remain different propositions.",
      "refs": [
        "D3"
      ]
    },
    {
      "title": "Inspector’s assessment",
      "text": "The useful question is not whether a computer can make an avalanche happen. It is whether the model produces relevant outcomes within independently defensible ranges for terrain, snow strength and loading. Separate measured modern values from inferred historical ones. When an input has no 1959 measurement, show how changing it changes the result. Avoid treating the output of a tuned model as a unique solution.",
      "refs": []
    },
    {
      "title": "Reconstruction limits",
      "text": "A physical trigger, an evacuation decision, subsequent movement and later exposure form different stages. Establishing one stage does not automatically explain all the others. The dossier avoids graphic images and unsupported allegations about named individuals. Original legal and medical records are not reproduced here, and the English scientific papers should not be represented as certified translations of the complete historical investigation.",
      "refs": []
    }
  ],
  "timeline": [
    {
      "date": "1–2 February 1959",
      "text": "Fatal events occur during the expedition; the detailed sequence is reconstructed retrospectively.",
      "refs": [
        "D1"
      ]
    },
    {
      "date": "1959 search and investigation",
      "text": "Recovery and inquiry supply the historical material later researchers discuss.",
      "refs": [
        "D1"
      ]
    },
    {
      "date": "28 January 2021",
      "text": "The slab release and impact study is published.",
      "refs": [
        "D1"
      ]
    },
    {
      "date": "2022",
      "text": "Follow-up fieldwork and its implications are published.",
      "refs": [
        "D3"
      ]
    }
  ],
  "claims": [
    {
      "text": "A quantitative slab-avalanche model has been published.",
      "status": "Documented",
      "refs": [
        "D1"
      ]
    },
    {
      "text": "Avalanches are impossible in this region.",
      "status": "Challenged by later observations",
      "refs": [
        "D3"
      ]
    },
    {
      "text": "The model uniquely proves every action taken by the hikers.",
      "status": "Not established",
      "refs": [
        "D1",
        "D3"
      ]
    }
  ],
  "hypotheses": [
    {
      "title": "Delayed release of a small snow slab",
      "status": "Supported physical scenario",
      "support": "The published model addresses delayed failure and impact under specified assumptions.",
      "limits": "Historical snow conditions and the full sequence are not directly measured.",
      "test": "Repeat the calculation across input ranges and compare with all available site constraints."
    },
    {
      "title": "A different initiating event followed by exposure",
      "status": "Alternative not specified by this dossier",
      "support": "Exposure can be a later stage regardless of the original reason for leaving shelter.",
      "limits": "A general possibility without a specific supporting record is not a competing reconstruction of equal strength.",
      "test": "Identify dated evidence that discriminates between proposed triggers before adding a new narrative."
    }
  ],
  "tasks": [
    {
      "title": "Build an assumption ledger",
      "body": "For each model parameter, identify the source, range and whether it was measured, inferred or selected. Prioritise parameters that change whether a slab releases."
    },
    {
      "title": "Compare field and historical conditions",
      "body": "Create separate columns for modern surveys and 1959 evidence. Do not transfer a modern weather observation to the historical night."
    },
    {
      "title": "Check the scope of the conclusion",
      "body": "List what the model directly addresses and what it leaves outside its scope. Keep these limits next to any summary or visual reconstruction."
    }
  ],
  "author": "Eklipsis",
  "content_languages": [
    "en"
  ],
  "path": "/enquetes/dyatlov-pass-1959",
  "source_url": "https://www.nature.com/articles/s43247-020-00081-8",
  "location_source_url": "https://www.openstreetmap.org/?mlat=61.75&mlon=59.45#map=8/61.75/59.45",
  "reviewed_on": "2026-09-29",
  "edition": 1
}