quartz/content/notes/avalanche.md

title	tags
avalanche

link: https://www.youtube.com/watch?v=-luspmL_f1o

• Lower risk
• Avoid avi terrain
• safety gear
• what to consider
• using a guide

Reducing risk

• total avoidance (dont go backcountry at all)
• avoidance lite (avoid all avalanche terrain)
• recognising risk, accepting it, minimizing exposure
• use bulletin

avoidance

• stay in bounds/on piste
• use low angle slopes
• steep: 30-45 degrees

minimize exposure to risks

• know if you are in avalanche terrain
  • maps, guidbooks, photos
  • clinometers
  • quality level 1 course

Use the bulletin forecast

• low
• moderate : natural avalanches not likely, man made avalanches possible if you ski in the wrong spot
• considerable: if you ski in the wrong spot, human triggered avalances are likely

no overhead hazard: not below a large face or something

avalanche problem:

• persistent weak layer
• wind drifted snow

whoomps under skis: collapsing snow, avalanches likely

Video 2

link: https://www.youtube.com/watch?v=1r0YIgdjm6M

lots of different types of avalanche. loose vs slab, wet vs dry.

usually: strong snow over weak snow.

strong: often wind effect: ltighly bonded grains weak: light snow with no wind and cold clear nights

important: slope angle

Snowpack tests

link: https://www.youtube.com/watch?v=OvwhuP4qtQg

• compression test

  • locating instabilities near surface
  • 30(upslope not horixontal) x30cmx110cm ()
  • 
  • tap 10 times with finger tips
    • mark factures as easy
  • level column
  • tap 10 times with finger tips from elbow
  • level
  • tap with hand or fist from shoulder
  • 
  • 
  • facture types video: http://vimeo.com/30996756

• deep tap test

  • similar to compression test but tests only for weak persistent layer relatively deep in the snowpack

• extended column test

  • same as compresion test but 90cm wide not just 30cm
  • 

• rutschblock test

  • 

• propagation saw test

• shovel shear test

• hand shear test

equipment

• shovel
• probe
• snow saw
• ruler
• cord