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Outline • Who’s at risk • Types of avalanches • What causes avalanches

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Presentation on theme: "Outline • Who’s at risk • Types of avalanches • What causes avalanches"— Presentation transcript:

0 Avalanche Avoidance and Companion Rescue

1 Outline • Who’s at risk • Types of avalanches • What causes avalanches
• Avalanche avoidance • Companion/beacon rescue • Educational resources • Q and A • Level one/edu. resources - slide of snowpit being dug: pointing out how you will go into the fied and study the beast. Things you’ll learn

2 Snowmobilers lead North America in fatality statistics
who’s at risk Snowmobilers lead North America in fatality statistics The number of avalanche fatalities involving snowmobilers has been climbing steadily for the last 10 years. 2

3 Snowmobilers don’t understand the causes of avalanches
who’s at risk Snowmobilers don’t understand the causes of avalanches

4 Slab Avalanches cause almost all avalanche fatalities
types of avalanches Slab Avalanches cause almost all avalanche fatalities

5 Point Release Avalanches more easily predicted, usually less dangerous
types of avalanches Point Release Avalanches more easily predicted, usually less dangerous

6 Understanding what causes avalanches will help you avoid them
• Weather • Terrain • Snowpack • Human Factors - Check the local avalanche hotline/web-site - Know the snowpack (local knowledge)

7 Most avalanches occur during and after storms
what causes avalanches − weather Most avalanches occur during and after storms New snow adds weight (stress) to the snowpack. New snow takes time to bond to layer underneath.

8 Wind transports snow (weight)
what causes avalanches − weather Wind transports snow (weight) Loading Cornice Wind loading direction Crown Notice anything else?

9 Temperature, elevation & aspect all will affect snowpack stability
what causes avalanches − weather Temperature, elevation & aspect all will affect snowpack stability • Rapidly warming temperatures can weaken the snowpack • You can have stability at one elevation but as you climb or descend the snow profile can change • Similarly, a slope at one aspect can be safe but at a slightly different aspect can be very unstable

10 The majority of avalanches occur on slopes between 30°- 45°
what causes avalanches − terrain The majority of avalanches occur on slopes between 30°- 45°

11 Slope shape is also a factor
what causes avalanches − terrain Slope shape is also a factor Most slabs release on the bulge of convex slopes Slabs can be triggered from above and below the slope Convexity Concavity

12 Dense trees can act as “anchors” and points of safety
what causes avalanches − terrain Dense trees can act as “anchors” and points of safety

13 Weak snowpack usually a strong layer over a weak layer
what causes avalanches − snowpack Weak snowpack usually a strong layer over a weak layer • Learn to evaluate the snowpack • There’s no substitute for on-snow avalanche instruction • Take a Level I avalanche course • Practice - slide of snowpit being dug: pointing out how you will go into the fied and study the beast. Things you’ll learn

14 Some slab avalanches are huge
what causes avalanches − snowpack Some slab avalanches are huge

15 Killer avalanches most are small and human triggered
what causes avalanches − snowpack Killer avalanches most are small and human triggered 1. What triggered this slide? 2. Where did the slope fail? 3. What’s the slope angle? 4. Where did the debris flow? 5. Could this slide have killed you? 1. Skier 2. Slope convexity 3. Roughly 30 degrees 4. Debris slid into concavity 5. Yes!

16 Know before you go! • Call local avalanche forecast center
what causes avalanches − snowpack Know before you go! • Call local avalanche forecast center • Know the snowpack history • Talk to others who have been out

17 what causes avalanches − human factors
Attitude: People sometimes ignore danger signs due to pride, ego and ambition. Time: Weekend warrior syndrome. Blue Sky: Sunny weather sometimes draws people too soon after a storm. Herding Instinct: People tend to think less in large groups.

18 Reducing your risk good sledding habits
avalanches avoidance Reducing your risk good sledding habits 1. Expose only one person at a time 2. Stay out of avalanche run out zone 3. Never cross above your partner 4. Have an escape route planned 5. Travel in the same route when possible 6. Keep your partner in sight 7. Travel to points of safety

19 Consider the terrain consequences during route selection
avalanches avoidance Consider the terrain consequences during route selection Don’t just look up, look down Will I get carried over a cliff? Will I get pinballed in the trees? Will I get dragged through sharp rocks? Will I be buried?

20 Companion/beacon rescue

21 Asphyxiation is the primary cause of avalanche fatalities
companion/beacon rescue Asphyxiation is the primary cause of avalanche fatalities 25% 75% Source: AAA

22 …but if you get to them fast enough, you can save them
companion/beacon rescue …but if you get to them fast enough, you can save them If recovered within 15 minutes, chances of survival are almost 92% At 35 minutes, survival rate drops to 37% After that, the success rate is extremely low. Source: AAA (422 completely buried victims)

23 …and most likely only if you have an avalanche transceiver
companion/beacon rescue …and most likely only if you have an avalanche transceiver Search Method Search Time Searchers beacon <15 minutes 1 person search dog minutes 1 trained dog coarse probe 4 hours person probe line fine probe hours person probe line Source: AAA Search times in 100mx100m area

24 If an avalanche occurs and you are the victim
companion/beacon rescue If an avalanche occurs and you are the victim • If caught, yell so other people see you. Then close your mouth. • Try to ride to flanks of avalanche. Get away from sled if you lose control. • Fight with all of your effort, try to stay on the surface. • As the snow slows, try to thrust a hand upward above the snow surface. • Before the snow stops, try to clear an air space in front of your face. • If buried, do not panic! Stay calm and try to relax.

25 If an avalanche occurs and you are a rescuer
companion/beacon rescue If an avalanche occurs and you are a rescuer • Watch the victim(s) as they are carried down the slope. Look for “last seen point.” • Make sure it is safe to begin a search. • Organize the search party. • Mark the area where the victim was last seen and begin search here. Look for any clues. • Begin beacon search. • When victim is located, confirm depth and location with a probe. Dig fast but carefully.

26 What do you need for a rescue?
companion/beacon rescue What do you need for a rescue? 1. Avalanche beacon follows electronic signal to buried victim 2. Probe verifies depth and location of buried victim 3. Shovel removes snow 4. Backpack to carry your shovel and probe

27 Resources IASA Avalanche Education Repository www.snowiasa.org
educational resources Resources IASA Avalanche Education Repository

28 Avalanche Avoidance and Companion Rescue
Questions?


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