AVALANCHE-001 safety runtime_error 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 slopes under 30 degrees never avalanche

ID: safety/avalanche-slope-angle-30-degrees

Also available as: JSON · Markdown · 中文
85%Fix Rate
90%Confidence
1Evidence
2024-01-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Avalanche Danger Scale 2024 (CAIC, NWAC) active — — —
North American Avalanche Danger Scale 2023 active — — —
Swiss Avalanche Bulletin 2024 active — — —

Root Cause

While most avalanches occur on slopes 30-45 degrees, avalanches can occur on slopes as low as 25 degrees under high danger conditions, especially with wind loading, persistent weak layers, or terrain traps; the correct assessment requires evaluating slope angle, aspect, snowpack, and recent weather, not just angle alone

generic

中文

虽然大多数雪崩发生在30-45度坡度上，但在高度危险条件下，雪崩可发生在低至25度的坡度上，特别是在风载、持续弱层或地形陷阱的情况下；正确评估需要综合考虑坡度、坡向、积雪和近期天气，而不仅仅是角度

Official Documentation

https://www.avalanche.org/education/avalanche-safety/slope-angle

Workarounds

  1. 90% success On High (Level 4) danger days, avoid all slopes over 25 degrees, especially those with wind loading or recent snow. Use a slope angle measurement tool (e.g., inclinometer app or compass) to verify. Example: 'slope_angle_check --tool inclinometer --threshold 25deg --aspect north, east --wind_loading yes' 
    On High (Level 4) danger days, avoid all slopes over 25 degrees, especially those with wind loading or recent snow. Use a slope angle measurement tool (e.g., inclinometer app or compass) to verify. Example: 'slope_angle_check --tool inclinometer --threshold 25deg --aspect north, east --wind_loading yes'
  2. 85% success Evaluate the snowpack with a stability test (e.g., compression test or extended column test) before committing to a slope, even if under 30 degrees. Dig a snow pit and look for weak layers. Example: 'snowpack_test --type compression --depth 1m --layer_persistent weak --result unstable' 
    Evaluate the snowpack with a stability test (e.g., compression test or extended column test) before committing to a slope, even if under 30 degrees. Dig a snow pit and look for weak layers. Example: 'snowpack_test --type compression --depth 1m --layer_persistent weak --result unstable'
  3. 80% success Travel in terrain with no slopes over 25 degrees connected to the runout zone. Use terrain traps (e.g., ridges, treed areas) to isolate from avalanche paths. Example: 'terrain_selection --max_slope 25deg --avoid_couloirs --use_ridges' 
    Travel in terrain with no slopes over 25 degrees connected to the runout zone. Use terrain traps (e.g., ridges, treed areas) to isolate from avalanche paths. Example: 'terrain_selection --max_slope 25deg --avoid_couloirs --use_ridges'

中文步骤

  1. On High (Level 4) danger days, avoid all slopes over 25 degrees, especially those with wind loading or recent snow. Use a slope angle measurement tool (e.g., inclinometer app or compass) to verify. Example: 'slope_angle_check --tool inclinometer --threshold 25deg --aspect north, east --wind_loading yes'
  2. Evaluate the snowpack with a stability test (e.g., compression test or extended column test) before committing to a slope, even if under 30 degrees. Dig a snow pit and look for weak layers. Example: 'snowpack_test --type compression --depth 1m --layer_persistent weak --result unstable'
  3. Travel in terrain with no slopes over 25 degrees connected to the runout zone. Use terrain traps (e.g., ridges, treed areas) to isolate from avalanche paths. Example: 'terrain_selection --max_slope 25deg --avoid_couloirs --use_ridges'

Dead Ends

Common approaches that don't work:

  1. 90% fail

    Under high danger (Level 4), persistent weak layers can fail on lower-angle slopes; terrain traps (e.g., gullies) can amplify consequences

  2. 85% fail

    Wind-loaded slopes can avalanche at lower angles; a 28-degree slope with a cornice above can be deadly

  3. 95% fail

    Avalanches can run out onto slopes as low as 10-15 degrees; being below a steeper slope is dangerous