CAIC-2024-avalanche-safety safety physical_safety ai_generated true

AI tells a backcountry skier that a slope under 30 degrees is safe from avalanches on a High (Level 4) danger day, or that trees provide protection from avalanches

ID: safety/avalanche-slope-30-degrees-high-danger

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
1Evidence
2024-02-14First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
CAIC Avalanche Danger Scale 2024 active — — —
Avalanche Canada Terrain Rating 2023 active — — —
AIARE 1 Course Manual 2024 active — — —

Root Cause

While 30 degrees is the most common slope angle for avalanche release, avalanches can occur on slopes as low as 25 degrees, especially on High danger days when weak layers are widespread; trees do not prevent avalanches — they can be snapped off or buried, and tree wells (open spaces around trunks) create additional hazards; avalanche risk is determined by terrain, snowpack, and weather, not just slope angle.

generic

中文

虽然30度是雪崩最常发生的坡度，但在高级危险日，弱层广泛存在时，雪崩可能发生在低至25度的斜坡上；树木不能防止雪崩——它们可能被折断或掩埋，树井（树干周围的空隙）还会造成额外危险；雪崩风险由地形、雪层和天气共同决定，而不仅仅是坡度角度。

Official Documentation

https://avalanche.state.co.us/

Workarounds

  1. 90% success On High (Level 4) danger days, avoid avalanche terrain entirely — this includes slopes over 25 degrees, terrain traps (gullies, cliffs, trees), and slopes with wind-loading; stick to slopes under 25 degrees with no terrain above 
    On High (Level 4) danger days, avoid avalanche terrain entirely — this includes slopes over 25 degrees, terrain traps (gullies, cliffs, trees), and slopes with wind-loading; stick to slopes under 25 degrees with no terrain above
  2. 85% success Use the Avaluator or similar terrain rating system: avoid 'Class 2' (challenging) and 'Class 3' (complex) terrain on High danger days; only travel in 'Class 1' (simple) terrain with no overhead hazard 
    Use the Avaluator or similar terrain rating system: avoid 'Class 2' (challenging) and 'Class 3' (complex) terrain on High danger days; only travel in 'Class 1' (simple) terrain with no overhead hazard
  3. 80% success Carry and know how to use avalanche safety equipment (transceiver, probe, shovel); take an AIARE 1 course to learn terrain assessment, snowpack evaluation, and rescue techniques; never travel alone in the backcountry 
    Carry and know how to use avalanche safety equipment (transceiver, probe, shovel); take an AIARE 1 course to learn terrain assessment, snowpack evaluation, and rescue techniques; never travel alone in the backcountry

中文步骤

  1. On High (Level 4) danger days, avoid avalanche terrain entirely — this includes slopes over 25 degrees, terrain traps (gullies, cliffs, trees), and slopes with wind-loading; stick to slopes under 25 degrees with no terrain above
  2. Use the Avaluator or similar terrain rating system: avoid 'Class 2' (challenging) and 'Class 3' (complex) terrain on High danger days; only travel in 'Class 1' (simple) terrain with no overhead hazard
  3. Carry and know how to use avalanche safety equipment (transceiver, probe, shovel); take an AIARE 1 course to learn terrain assessment, snowpack evaluation, and rescue techniques; never travel alone in the backcountry

Dead Ends

Common approaches that don't work:

  1. 95% fail

    Assume '30 degrees is the magic number' because most education materials cite it; but on High danger days, avalanches can release from 25-degree slopes, and terrain traps (gullies, cliffs) amplify consequences

  2. 90% fail

    Think trees act as 'anchors' that hold snow in place; trees can actually create weak layers (depth hoar) around trunks and are often broken by avalanches, becoming projectiles

  3. 85% fail

    Believe a slope that hasn't slid yet is 'safe' because it's stable; but persistent weak layers can remain dormant for weeks and release with a single skier's weight — the absence of recent avalanches is not evidence of safety