Presentation about snow safety for MUMC

mumc-snow-safety-presentation.md

Snow Safety Presentation

Hypothermia

Mum will cover that topic.

Ice

• Bigger concern than avalanches. Has killed more people.

Rime

• supercooled water droplets, from fog/clouds that hits a solid object and freezes in place.
• high wind
• temperatures between -2 and -8 degrees celcius.
• forms on the windward side.
• good indication of wind direction
• Often forms on the snow surface, and on Sastrugi formations, awful stuff to ski over!

Melt/Freeze water

• Waterfalls (Blue Lake, Mt Buller, etc)

Corn/Firn/Neve snow

• Formed by snow repeatedly melting and freezing
• Can be caused by warm weather, sunlight, followed by freezing
• Can be accelerated/caused by rain, followed by freezing
• More common in the spring time
• Even if the air temperature is above freezing, the snow can still freeze if it is in the shade (or at night), and the sky is clear, the heat radiates away.
• Can be covered by other snow, and be patchy and hard to spot, requires careful attention.
• Glistening, different appearance, less like plaster white.

Safety Concerns and Risk Management

• Slipping, unable to arrest fall.
• Any fall on a steep slope, if not roped up, has a high probability of serious injury
• Surprisingly low slope angle if the snow is icy, can be fatal
• Don't fall or don't go
• Ice axe self arrest, learn, but it's a last resort, no guarantee.
• Careful with crampons, ski bindings, shoes, etc

Cornices

Locations:

• Mt Feathertop
• Mt Bogong
• Main Range (Blue Lake)

How do they form?

• Snow loading
• Predominant wind direction during snow fall

Examples of collapse:

• Newspaper article about Blue Lake avalanche/cornice collapse

Risk Management

• Similar to Seracs in the mountains of New Zealand
• Don't stand on top of cornices
• They break back further than you would expect
• Avoid travelling underneath cornices, especially when the weather is warming, or they are being loaded with new snow.
• For some routes, they may be an objective hazard, where the risk is managed by reducing time exposed to the hazard.

Avalanches

Avalanche Triangle

Slope Angles

• explain range, and probability
• how to assess on maps and in the field

Terrain Traps

• Gullies
• Trees
• Cliffs

Types

• Storm Slab

• Loose Wet

• Persistent Slab (less common in Australia)

Snow Conditions

Warning signs:

• MSC Website - warnings (not always up to date, but far better than nothing).
• Prolonged cold weather below zero
• Plenty of new snow

Rescue Techniques

• Go do a course
• Not a guarantee of survival, many trauma injuries during avalanches.