Avalanche Avoidance and Companion Rescue. Outline. Who’s at risk. Types of avalanches. • What causes avalanches. Avalanche avoidance. • Companion rescue (beacon, shovel and probe). • Educational resources. • Q and A. Who’s at Risk?. Who’s at Risk?. Who’s at risk?. 1. Snowmobilers.
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Outline • Who’s at risk • Types of avalanches • What causes avalanches • Avalanche avoidance • Companion rescue (beacon, shovel and probe) • Educational resources • Q and A
Who’s at Risk? Who’s at risk? 1. Snowmobilers 2. Skiers 4. Snowboarders 3. Climbers
Who’s at Risk? About 97% of people killed in avalanches die while playing Source: CAIC 1996/97 to 2005/06
Types of Avalanches There are 2 types of avalanches • Slab avalanches • Point release/loose snow
Types of Avalanches Almost all fatal avalanches are slab avalanches
Types of Avalanches Point release (loose snow) avalanches are more easily predicted and usually less dangerous
Types of Avalanches Some slab avalanches are huge
What causes avalanches? If you understand the causes of avalanches you can avoid them • Weather • Terrain • Snowpack • Human Factors
What causes avalanches? Most avalanches occur during and immediately after storms • New snow adds weight (stress) to the snowpack and may not bonded to snow beneath
What causes avalanches? Weather: Wind transports snow (weight) Loading Cornice Wind loading direction Crown
What causes avalanches? Rapidly warming temperatures can decrease snow stability • You can have stability at one elevation but as you climb or descend the snow profile changes • Similarly, a slope at one aspect (orientation) can be safe but at a slightly different aspect can be very unstable
What causes avalanches? Terrain: The majority of avalanches occur on slopes between 30˚ and 45˚ 60˚ 45˚ 30˚ 15˚ 0˚
What causes avalanches? Convexity Concavity Slope shape and terrain features also need to be considered • Most slabs release on the bulge of convex slopes • Slabs can be triggered from above and below the slope • Dense trees can act as anchors and points of safety **But if the trees are open enough for making turns they’re not dense enough to anchor the snowpack
What causes avalanches? A weak snowpack usually consists of a strong layer (slab) overlying a weak layer (“sugar” snow) • Learn to evaluate the snowpack • There’s no substitute for on-snow avalanche instruction • Take a Level I avalanche course • Practice
What causes avalanches? Most killer avalanches are small and human triggered 1. What triggered this slide? 2. Where did the slope fail? 1. Skier 3. What’s the slope angle? 4. Where did the debris flow? 2. Slope convexity 5. Could this slide have killed you? 3. Roughly 30 degrees 4. Debris slid into concavity 5. Yes!
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 think less in large groups
Avalanche avoidance With good backcountry habits, you can avoid avalanche danger 1. Expose only one person at a time 2. Get out of the way at the bottom 3. Never cross above your partner 4. Have an escape route planned 5. Remove pole straps and safety straps 6. Travel in the same route when possible 7. Keep your partner in sight 8. Travel to points of safety
Avalanche avoidance What would happen to these two if an avalanche occurred?
Companion rescue Companion rescue Asphyxiation is the cause of most avalanche fatalities Trauma 25% Asphyxiation 75% Source: AAA
Companion 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% % Recovered Alive After that, the success rate is extremely low. Time in minutes Source:AAA (422 completely buried victims)
Companion rescue Only a member of your party or a companion will likely save your life Companion Rescue Search and Rescue 189 (68%) 58 (15%) Alive 317 (85%) Dead 91 (32%) 280 375 Source:CAIC
Companion rescue If an avalanche occurs Victim: 1. Yell so other people hear and see you. 2. If possible, ski or ride to the side of the moving snow. 3. Fight with all of your effort to stay on the surface. 4. As the snow slows, try to thrust a hand upward above the snow surface. 5. Before the snow stops, try to clear an air space in front of your face. 6. If buried, do not panic! Stay calm and try to relax.
Companion rescue If an avalanche occurs Rescuer(s) 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. Delegate tasks: visual search, beacon search, probing, shoveling. Mark the area where the victim was last seen and begin search here. Look for any clues. When victim is located, confirm depth and location with probe. Shovel strategically: begin downhill of victim.
Companion 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 equipment
Companion rescue There are three phases to an avalanche beacon search: 1. PrimarySearch 2. Secondary Search 3. Pinpoint Search
Companion rescue Multiple searchers can decrease recovery time 1. Primary 2.Secondary What does this guy do? 3. Pinpoint
Companion rescue A last seen point can also decrease recovery time.Keep your eye on the victim! Eliminates this area for searching Last seen point Search begins at star
Companion rescue Proper Probing • Begin probing at the lowest distance reading. • Probe in concentric circles until you strike the victim. • Make each probe hole about 10 inches (25cm) apart. • Your probe should enter the snow perpendicular to the slope. • Once you have confirmed the victim’s location, leave the probe in the snow.
Companion rescue Strategic Shoveling • • Shoveling consumes the majority of time and effort in an avalanche rescue. • • Do not take shoveling skills for granted. • Begin digging downhill of the probe about 1.5 times the burial depth (note depth marking on probe to determine this distance). • If one rescuer, make the hole at least one “wingspan” wide. • If more than one rescuer, work side by side, make hole two wingspans wide (about 6ft/2m).
Companion rescue Digging is the hard part!
Companion rescue Search Possible, Multiple Completely Buried Victims With Transceivers: 5 Incidents All Other Cases: 319 Incidents Recreationists should master single burial searching and strategic shoveling • In 366 avalanche incidents, only 5 (1.4%) were incidents where all victims were completely buried and wearing transceivers. • Almost all multiple burials can be solved as a series of single burials. • In interviews with witnesses, shoveling is always cited as more difficult and time consuming than beacon searching. Avalanche.org statistics 1997-2007
Conclusion Most of the time, snow conditions are safe in the backcountry. Learn to recognize when they are not! We encourage you to: • Learn more about what creates avalanche conditions. • Learn more about proper route finding. • Get in the habit of calling your local avalanche forecast center or looking at their reports online. • Practice your beacon, probing, and shoveling skills at a BCA Beacon Training Park near you. This presentation is not a substitute for a real, on-snow avalanche course.
Educational resources Resources U.S. www.avalanche.org Canada www.avalanche.ca Europe www.lawinen.org www.backcountryaccess.com/education/
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