Avalanche Safety Training 1 (AST1)

Trip Planning

  • 3-4km/hr horizontal
  • 1hr per 300m vertical

Avi Bulletin

avalanche.ca Read all three tabs (Danger Ratings, Problems, Details)

Danger Rating

This gives us the rating at 3 different altitudes, and a forecast of how it will change.

Problems

Specific sources of potential avalanches, including on which faces they may come from. These are things to investigate in the snow pack when out in the field.

Avalanche Sizes

  • 1: 10 ton
  • 2: 100 ton (can bury a person)
  • 3: 1000 ton (can bury a car/truck)
  • 4: 10000 ton (can bury trains)
  • 5: 100000 ton (can bury a village)

Maps

caltopo use to color slopes in an area. slop angle shading

gaia gps good for croud sourced gpx tracks.

Weather

mountain-forecast.com watch for precipitation/wind.

Packing for a Trip

  • transceiver/shovel/probe
  • skis/skins/poles/helmet
  • clothing/food/water
  • med kit/repair kit
  • compass/map

During the Trip

Observations:

  • cracks shooting from ski tracks means storm slab
  • woompf sounds when you step means hollow underneath
  • … remember more
  • sastrugi (ripples on surface) show direction of wind
  • 30-35º slopes are ideal for avis (and fun for skiing)
  • >20-25cm of precipitation is bad for storm slab.

Digging Pits

Skiing on the surface has a 60-70cm affect depth. Load is distributed well enough underneath. Digging a pit you don’t know if there is wind swept snow, or not, so dig deeper.

1) Find Layers

Slide your finger down the column feeling density. When you find a change, make a horizontal line to denote.

2) Find Layer Densities

In each layer, test the density. Push lightly with your fist, if you feel resistance at your elbow, poke with 5, then 4 etc fingers down to pencil resistance.

3) Column Test

Make a 30cm x 30cm isolated column of snow. then start tapping on a shovel layed on top, watching for any shears or changes in the column below.

  • 10 taps of fingers bent at wrist
  • 10 taps of hands bent at elbow

Companion Rescue

<10min for rescue >90% chance of survival. Steep drop off after that.

1) coarse search1

Follow arrow, make sure number is going down. If number is going up, turn around.

  • Do not rotate transceiver.
  • forwards/backwards close to the snow, finding lowest number
  • repeat left/right.

3) probe

spiral 30cm strikes apart. if you strike, read the depth.

4) dig

45º slope in to deeper burials.