CHAPTER FIVE

AVALANCHES

Credit: Simon Steinberger.

If you’ve ever watched a video of an avalanche, then you know they are capricious, sudden, and powerful forces, moving with breathtaking speed down steep mountains and destroying large swaths of forest. Between 1975 and 2000 almost seventeen thousand people have been killed in landslides (rock and dirt) and avalanches (snow and rock and dirt) worldwide. Avalanches kill more than 150 people worldwide each year and over twenty-five deaths annually in America. In 90 percent of avalanche accidents, the victim or someone in the victim’s party causes the snow slide. Asphyxiation is the most common cause of death in an avalanche, claiming about 90 percent of victims. Because, only a few seconds after an avalanche the snow quickly turns into ice, freezing hard as cement. Eighty-nine percent of victims are men.

We have pretty good statistics for deaths and injuries in avalanches, but have you wondered how many escape an avalanche by the skin of their teeth? It’s a loose calculation but experts believe that for every death, about ten people are caught in an avalanche of snow and ice and somehow escape with their lives.

If you get buried in an avalanche, you only have a 27 percent chance of survival after thirty-five minutes. After one hour, only one in three victims buried in an avalanche is found alive. Statistics show that 93 percent of avalanche victims survive if dug out within fifteen minutes. Suffocation is responsible for most avalanche deaths, and trauma is the cause of 24 percent of the deaths. The last one percent are killed by hypothermia. Avalanche victims are typically backcountry recreationalists: skiers, snowboarders, climbers, and snowmobilers. With the rising popularity of snowmobiling, snowmobilers now account for twice as many avalanche fatalities as other groups. Since snowmobilers weigh more, the risk of stressing the weak layer in a snowpack and setting off an avalanche is greater.

Avalanches are caused by four factors: a steep slope, snow cover, a weak layer in the snow cover, and a trigger. By the way, it’s a myth that noise triggers avalanches. Avalanches can be triggered by wind, rain, warming temperatures, snow, and earthquakes. They can also be triggered by skiers, snowmobiles, hikers, vibrations from machinery or construction. We mostly think of avalanches and skiers or snowboarders but if you are staying in a hotel or home near a snowy mountain, well, you could be in danger too. Avalanches are most common in mountainous areas of Utah, Alaska, Idaho, Montana, Alaska, California, Washington, and Oregon.

Steeper slopes carry a greater risk of a snowslide. Slab avalanches are the most dangerous type of avalanche and account for as much as 90 percent of all avalanche-related fatalities. Slab avalanches are formed when snow gets deposited by wind. When they fracture, they look like a heavy block of snow cut out from the side of the mountain and can vary in thickness from a few inches to a few feet. A slab avalanche is essentially an entire cohesive plate of snow that breaks free and slides across a weaker layer and can accelerate to between 60 miles per hour and 80 miles per hour in as little as five seconds. The heavy dry slab avalanches can top 100 to 200 miles per hour at top speed but the wet snow avalanches move much slower, perhaps in the 20 miles per hour range.

The other types of avalanche are loose snow avalanches which are common in steep terrains and usually occur in fresh-fallen snow; powder snow avalanches which form a cloud of powder over the avalanche; and wet snow avalanches which tend to move slowly (heavy with water) but can still be destructive of trees, rocks, and property.

Even though we cause most of the avalanches that affect us, these forces of nature do occur naturally as well. They might happen when there is an increased load of snowfall. They might happen from the melting from solar radiation, or it might be from rain, rock, or ice falling, or even earthquakes.

Snowmobiling, a major factor in triggering avalanches. Credit: Pixabay.

Trigger points that activate an avalanche are usually at locations where the top slab of snow is thinner. Most avalanches occur on slopes with angles between 30 and 45 degrees (38 degrees is the most common slope for an avalanche.) Steeper slopes tend to slough snow when it gets too deep so that a snowpack doesn’t build up.

Avalanche risk is at its greatest twenty-four hours following a snowfall and this is because often, fresh snowfall does not bond well to the underlying snow. This new snow on old snow is the recipe for a slab avalanche. If you get a foot or greater of fresh snow you have a much greater avalanche risk than snowfall cover less than a foot deep.

A great resource for avalanche information, maps, and up-to-date avalanche warnings and dangers is www.avalanche.org.

Preparation

Avalanche Survival tends to fall into five categories: Education, Equipment, Observation, Traveling in Numbers, and Survival Techniques.

Be avalanche aware when skiing in the backcountry. Credit: Pixabay.

1. Education

If you are planning to travel in backcountry, it makes sense to take an avalanche safety course. Route-finding, avalanche safety, and rescue skills are the basics you will need to know. If you are in mountainous country, you’ll find many organizations that will provide intensive training courses for snowmobilers, skiers, and snowboarders on how to spot avalanche risk, avoid avalanches, survive if caught in one, and how to rescue each other.

Instructors can show you how factors like precipitation, wind, temperature, snow stability, and terrain set up possible avalanches. You will learn to recognize how slope steepness, orientation, and underlying rock affect conditions. They teach you to check snowpack stability, route recognition, and how to dig pits. Safety classes also teach you how to use beacons, probes, and shovels (yes, there are efficiency techniques and group strategies). Get to know the danger rating definitions for the five international avalanche danger levels: 1 (low), 2 (moderate), 3 (considerable), 4 (high), 5 (extreme).

Avoid avalanche danger areas and observe warning signs. Credit: Pixabay.

Before you head out on the slope, you have several things you need to do:

Read the official avalanche forecast bulletin for your area. Travel with people who have a similar approach, education, observation, and sense of safety. Have all the right equipment at hand. Don’t get out there and remember you left something at home. You might have to save a life today (and it might be yours).

Have you trained with your safety equipment? If you don’t know how to use it, you’re taking a big chance. Go out with a friend beforehand and get familiar with your gear. Doesn’t hurt to refresh yourself every so often either. Have your phone with you? Does it have the phone numbers of local rescue services and other important contacts? Is it fully charged? Is it in a dry pocket or in a waterproof case? Do you and your friends have a good idea of the area and routes you’ll be traversing? Are one of you carrying maps or a guidebook or a GPS mapping device with you? Do you feel comfortable on how to identify slopes of 30 degrees or more? And make sure to talk to local professionals to get every bit of local information on your area and any risk involved.

The factors that increase (or diminish) the likelihood of an avalanche occurring are surprisingly complex—things like weather, sun, temperature, wind, the angle of the mountain’s slope, and snowpack conditions. The avalanche hazard level can fluctuate daily and even hourly as conditions change. This means that the ability to scout for potential avalanches takes a good amount of both education and preparation.

2. Equipment

An avalanche transceiver helps rescuers locate a person buried by snow. Credit: Bodhisattwa, creativecommons.org_­licenses_by-sa_4.0, Wikimedia Commons.

The most basic equipment each backcountry traveler should carry include helmet, receiver (you’ll see it called a transceiver) and probe, and shovel. Your helmet should have a face shield and it makes sense to have a good seal around the neck. To carry the other gear, you need a backpack for skiing or if you snowmobile, have your bag easily accessible for all your gear. You want your receiver on your person of course. The case can be made that no matter if you are skiing, snowboarding, or snowmobiling, you should carry all your gear on your person in case your snowmobile is buried or out of range.

Avalanche Transceiver (Beacon)

A probe and shovel used by a rescue teams during search-and-rescue drills. Credit: Iain Lees, creativecommons.org_­licenses_by-sa_2.0, Wikimedia Commons.

This should always be on your person in avalanche terrain. These devices send snow-penetrating radio waves on a standard frequency all the time. If someone is caught in an avalanche, switch yours to receive to hone-in on your partner’s position. Easier to use than ever, these devices still require proper technique and practice. Beacons transmit a radio frequency to a receiver or another beacon. This enables your rescuers to pinpoint exactly where you are underneath the snow before they start digging. Some jackets or clothing have embedded technology that can help rescuers to locate a buried skier.

Probe

Locate where your partner is buried by the avalanche. A probe will help you dig in the right spot so you’re not digging wastefully. Every second counts. A probe is also great for tracking snow depth and locating crevasses.

Shovel

Dig hard, dig efficiently! Digging in the packed snow is going to be difficult, so make sure you have the right kind of shovel and know the proper technique. Besides, what if you got caught out overnight? With your shovel you can check out snow depth or dig a snow shelter and survive. Most avalanche-shovels fit on your back.

Avalanche airbag (balloon system)

An avalanche airbag. Credit: Nolispanmo, creativecommons.org_­licenses_by-sa_3.0, Wikimedia Commons.

An ABS (airbag system) is an attempt to thwart getting buried by an avalanche. You wear the airbag and if you are in avalanche danger, you immediately activate the bag. It blows up like a balloon and while it might not keep you from getting buried, the idea is that it keeps you closer to the surface. Experts say the results are mixed and the costs are still high enough to be prohibitive. If you can afford it, buy and use the ABS.

Dress warmly, knowing that if you or a buddy get caught in an avalanche, it could be hours (or longer) before you can get to a warm place again. Pack a small first aid kit too, if you can. Skiers should wear releasable bindings and not use the pole straps. Snowboarders should rig their bindings with a ripcord to release the snowboard in a hurry.

Another tool that is showing promise in avalanche survival is the AvaLung, a snorkel-type device that aids breathing if you are buried. The AvaLung uses a mouthpiece to draw oxygen and dispel carbon dioxide. Since asphyxiation is the major killer when buried, any time you can buy gives you a great chance at surviving until you can be rescued.

3. Observation

Credit: Pixabay.

The most important element of avalanche safety is to use your education to observe the signs of an impending or possible avalanche so you can avoid one altogether. When you combine all your education and observational skills in a group effort, you maximize your chances of enjoying the backcountry with no avalanche event. Check your local forecast the night before and morning of your possible trek. Study where the most dangerous slopes might be. Make sure everyone in the group is on the same page.

Call or get online to check the area avalanche report. The many mountainous areas in North America typically have avalanche centers that issue regular avalanche advisories. This gives you an easy, overall view of snow stability for your area. There are some smartphone apps that display updated information.

The best indicator of possible avalanches are other avalanches. You can’t get much more obvious than that. But it’s surprising how often people miss this clue. Another good indicator of worsening avalanche conditions include any weather change that is rapid, such as recent rapid loading of new or windblown snow, recent rapid warming, recent rapid melting, and rain on new snow.

Credit: Pixabay.

When driving, observe any warning signs advising about avalanches. Drive carefully in avalanche areas. Avalanches may hit or cover the road without warning. Head on a swivel. Obey road closures. If an avalanche blocks the highway, remain in your vehicle with seat belts on and call emergency services and wait for assistance. It is easier to find a car in the snow than it is to find a person. If you can reverse safely, do so but make sure to alert other drivers and call emergency services.

On the initial part of your party going into the backcountry, especially if it is an ascent, be observant. Traverse low-angle ridges, near dense forest, away from dangerous slopes when possible. Move from safe zone to safe zone, and if you must cross areas that seem avalanche-prone, spread out so not everyone is exposed to danger.

Listen for collapsing snow. When you hear the snowpack collapse, your ear just told you that things are unstable. Stay off of steep slopes. Don’t go underneath steep slopes. Listen for cracking or whooping snow. Recent wind loading is the culprit for cracking snow and in fact, the longer the crack, the more dangerous it is.

When it’s time to let her rip, have fun in the backcountry, but don’t become un-observant. Keep using the same evaluation skills you have been, keep identifying safe zones versus danger zones and maintain safety for the entire party. Don’t be afraid to stop and judge snow stability, to back off a line or an area, and don’t get careless on that “last run” of the day.

4. Traveling in Numbers

When traveling in backcountry, always travel in a group. It’s a good idea to have an experienced group leader. Always stay within view of your group.

Is everyone geared up? Knowledgeable about your routes? Watching carefully for any possible dangers? As each person is about to commence their fun route, have you talked it over with the group to minimize any triggering? Before you commit to your route, visualize what an avalanche would look like on the slope. Talk about it with your group. Where can you move to reduce your avalanche hazard? Your party should have an evacuation plan of sorts and be equipped for winter travel with warm clothes, snacks, and first aid in case things go awry. There is strength in numbers especially in an avalanche, even more so in avalanche rescue.

Travel in numbers when in the backcountry. Credit: Pixabay.

5. Survival Techniques

See below.

Survival

Homes, buildings, and roads can also be in avalanche danger zones. Credit: Scientif38, creativecommons.org_­licenses_by-sa_3.0, Wikimedia Commons.

If you’re caught in an avalanche, the best thing you can do is try to get out of the avalanche! Sounds good, right? But how do you do that?

First, what happens when you are caught in an avalanche? You are wearing a helmet because once it starts, you might be tossed around, careen roughly into a tree, or get hit by debris. This maelstrom will occur suddenly and survivors say the sensation is like being caught in a high-speed washing machine. If you can, jump uphill, above the fracture. If you can’t do that, run or slide to the side of the avalanche. We know, easier said than done, but if you can, do it. If you’re on skis or a snowboard, head downhill first to gather some speed, and then veer to the side and off the slab. If you’re on a snowmobile, keep going in the direction you were going and throttle it to get off the sliding snow. The presiding idea is to get off the slab, out of the avalanche, do whatever you can to escape.

If none of that works and you are in the tumult of the avalanche, drop your ski poles or abandon your snowmobile—you don’t want to have those things weighing you down, twisting in the snowslide and hurting you, or in the case of the snowmobile, landing on top of you. You do not want your skis on as you tumble nor do you want your ski poles attached to your wrists. You need to be light and buoyant. Here’s the tough part: you need to free yourself up while deploying your ABS and finding your AvaLung. And that’s not all … you should be trying a few survival techniques.

Swim. Swim with all your might and ferocity. Try to stay on top. Experts will tell you to lay back and do the backstroke to avoid the toe (tip) of the avalanche, the most turbulent part of any avalanche. But do whatever it takes to avoid being buried. You may be disoriented in the initial thrust but as it slows, fight to get to the top. Avalanche debris has a similar mass to setting concrete, and further movement becomes impossible.

Dig. Some survivors suggest digging in with your feet to slow your descent. Some have also said that rolling their body like a log helped them get to the side of the flow.

Reach. Try to keep one arm above your head, above your body on your violent descent. This is easier said than done, but try to keep one arm above your head as the avalanche tosses you around. If you can pull this off, it will be easier for rescuers to spot you if your arm or hand is sticking up out of the snow; and if your arm is out of the snow, you’ll know which direction is up.

If you’re wearing an ABS backpack, pull the trigger and release your airbag. Hopefully this will keep you on the surface. Never wear wrist loops in a potential avalanche zone.

Try to keep your nose and mouth free from snow and use your arms to establish space around your face before it finally stops. Push machinery, equipment, or heavy objects away from you to avoid injury.

When a slide stops it will quickly settle like concrete, so as the snow begins to set up, take a big breath. This expands your chest, which can give you a little extra breathing room as the snow hardens around you. If rescuers can dig out the victim within fifteen minutes, there is a 90 percent chance of survival, so time is of the essence. After that the odds drop quickly. Only 20 percent of buried victims are still alive after forty-five minutes, and beyond two hours, few ever survive. Everything you can do to aid the rescuers helps your chances at survival.

As the avalanche slows to a stop, push yourself towards the surface. Attempt to make an air pocket in front of your face using one arm and if you are able, push your other arm towards the surface.

Once the Avalanche Has Buried You

If the avalanche buries you, you survived any serious trauma, and you’re still alive, well, you are lucky. About 33 percent of avalanche victims are killed by trauma. But your window for survival is small so hopefully, you’ve done all the preparation and education, including wearing a receiver. If you are able, try to create an air pocket by putting your arm across your face as the mass slows. Every little bit of breathing room is vital so this doesn’t become your snowy tomb.

Because you are buried, trapped from a tumultuous event, you probably won’t know which way is up. You’ll also be in panic mode—who wouldn’t be? The snow may be so packed you cannot move your fingers or expand your chest to take a big breath. But the calmer you are, the slower you will breathe and the less quickly you’ll use up the oxygen. You will want to turn your head side to side and create whatever little air pockets you can so you can breathe.

Don’t yell either. It’ll waste energy and oxygen and since snow is insulating, rescuers are not likely to hear you. If you’ve worn your beacon, rescuers will be on the way, and you’ll get pulled out of the debris soon. If you hear a rescuer nearby, a quick loud shout is worth the risk.

Rely on Your Buddies

Observation is the key. If you see the avalanche occur and your buddy get caught in it, watch closely to see if you can follow your buddy’s path and where he or she has stopped. This is where practice with your avalanche rescue gear, education from experts, and team coordination all coalesce.

When backcountry skiing with others, traverse the mountain one at a time. Credit: Simon Steinberger.

Aftermath

A helicopter during a rescue. Credit: Pixabay.

You’ve just witnessed one or more of your party get caught up in an avalanche? First, stay calm. Second, keep your eyes on them. Watch your buddy carefully from the time they are swept away until they aren’t visible beneath the snow. Keep particular care to note where they were swept away to where they disappeared until the avalanche comes to a stop. Knowing this area will give you an idea of where they might have ended up. After the avalanche has come to a full stop, go and find them. You are trained in using your avalanche beacon and metal probe so you can hone in on where they are buried. Waste no time. Start digging.

Because asphyxiation is the most common underlying cause of avalanche deaths, the more quickly a victim can be located and dug out, the higher the chance of survival. Your first instinct might be to go for help. Do not go for help. You and your buddies are the best hope. We cannot emphasize enough that time is of the essence.

Let’s just say your buddy was in a hurry, and careless, and forgot to wear a beacon. This is one reason that the continued sightline of their path is important. Look for clues on the surface. Can you find their skis, hat, gloves, or ski poles? Many times, these provide a line to where the victim is buried. Because of the dynamics of moving snow, victims often get buried in certain places—above rocks and trees, on the outside of the avalanche path if it curves. If you lost track of your buddy, probe these spots.

So your buddy wore a beacon and you have located it under the snow? Digging takes a while because you may have to move a lot of snow and it’s usually hard packed. If you can determine that the victim is buried just under two to three feet of snow, start digging furiously to reach them. But if they’re buried in snow that’s deeper than that, you should employ different digging strategies, depending on how many people you have with you.

If you have several available diggers, form a “V.” The front person does the digging, and moves the displaced snow just a little ways behind him or her. The two people behind the digger then push the snow to the people behind them, and on down the line. The front person is rotated every minute or so, so that the digger remains fresh. If it’s just you and the buried victim, you’ll want to employ the “strategic digging” method. When you locate someone with a probe and know exactly where they are in the snow, you don’t want to dig straight down into where the probe is sticking out of the snow. The probe might be at their legs, and when you dig down, you may shovel snow behind you and onto their air pocket, collapsing it. Then you’ll end up with a cone-shaped hole that’s not at their airway.

Instead, shift your position to downhill from the probe, about one to two times the length of the depth in which the victim is buried. Start digging into the side of the slope, straight into where you think your victim is buried. To save more time and energy, shovel the snow out to the side instead of behind you, until the snow rises to your waist—then start moving it downhill. Uncover their face and clear an airway as soon as you can.

Once you locate the victim, before you pull them out, clear their airway and make sure they can breathe properly. Remove them from the snowpack and lay them down where you can continue to clear their airway, perform CPR, and administer first aid.