This post may contain affiliate links. For more information, see our affiliate disclaimer here.
Neverending pristine white slopes that are a dream come true for most skiers can quickly become a deadly threat in no time. Avalanches are a HUGE CONCERN for all skiers, snowboarders, and anyone living in mountain areas with heavy snowfall.
Typically, avalanches can be natural or triggered by humans. But man made of natural, both are responsible for over 150 deaths a year worldwide. In the United States avalanches account for, on average 27 deaths each year. A typical avalanche victim is a male in his twenties.
Who’s at Risk?
Proximity puts you at a higher chance of being affected by it. Anyone can be trapped in an avalanche no matter how many precautions you take, the best thing you can do for yourself – is to stay away from a slope with fresh snow. People participating in winter sports are at a higher risk of being trapped in an avalanche, this includes:
- Skiers Hikers.
- Backcountry tourers.
Of course, there are many others also at risk from avalanches simply because of where they live and where they travel. Avalanches come in many scales from those that cause nothing more than an inconvenience to those that take lives. Which is why it’s important that people are aware of the different Types of avalanches, what Causes them, and the Warning Signs to be aware of. As well as the means to Protect and save themselves.
Winter sports are wonderfully freeing activities — until you find yourself buried under a massive pile of snow! In those moments, you’ll need not only the will and determination to live but specialist knowledge to give you, and anyone else in your group, a fighting chance of survival. Preparation and knowledge are key, so, keep reading.
What causes avalanches?
One of the most common questions asked about avalanches is ‘Why do they happen?’ Some people still believe that a sudden noise can trigger an avalanche, however, that’s not true at all. Most avalanches are natural — they occur because of several natural factors working in conjunction.
Typically, a disturbance causes an avalanche, it can be natural or artificial (human-induced). This fractures the weak layer of the snowpack — the failure layer — that’s buried within it until it simply falls off. These disturbances are usually weather related, and depending on the type of disturbance, the slope, terrain, temperature, and other factors, they can cause a:
- Low avalanche hazard,
- Moderate avalanche hazard,
- Considerable avalanche hazard
- High avalanche hazard.
Luckily, the majority of naturally occurring avalanches don’t produce injuries or fatalities, since they typically happen in remote places. Over 90% of avalanches that caused death or injury, the injured party is believed to be the cause of the avalanche.
The causes of human-triggered avalanches
Skiers, hikers, and other adventurists love fresh snow. However, fresh, heavy snowfall is the main cause of most avalanches.
The first 24 hours following a storm with a snowfall 12” or more, is when everyone should be on high alert and the lookout for potential avalanches.
New, colossal snowfall might not blend well with the existing snowpack. What’s more, it can overbear it, and weaken the underlying layers. Then, all it takes is one trigger — like a skier, a snowmobile, snowboard, or just a group of hikers — and the weak layer will fracture.
The size of the fracture, and consequently, the avalanche, depends on various factors. Either way, a fracture will cause a formless mass of snow to start moving rather quickly down the slope of the mountain.
Massive avalanches are capable of reaching speeds of 80 miles per hour within just 5 seconds! Therefore, if you are the trigger of an avalanche — there’s no way you can outrun it!
Potential factors that could cause an avalanche
Several things might create the perfect conditions for an avalanche. Of course, humans will provide the final trigger.
As mentioned, heavy snowfall can cause a lot of fresh snow to accumulate over tan already weak snowpack. This creates instability and is the perfect base for a human-triggered avalanche.
Layering of snow
Sure, heavy storms with massive snowfall will surely tip us off that avalanches are a big possibility. However, gradual snowfall can also be dangerous. Various layers can fall over days or even weeks, and these layers might not grip together causing further instability.
One or several, of these layers, might be weak, which, as we mentioned, is what could ultimately fracture and cause an avalanche. The worst thing about this, we can never truly know for sure what’s buried deep within the snow. Thus, it’s important to consider in these conditions – an avalanche is always a threat.
Wind direction and temperature
Because wind direction determines the pattern of snowfall, it also determines how layers accumulate over the existing snow. So, a robust upward wind might ultimately cause a natural avalanche. Which is why it’s not recommended to go outside during heavy wind in areas where avalanches are common.
High temperatures can also cause avalanches because they cause the surface layers of the snow to start thawing. When the snow starts to melt, it can slide off even without a human trigger.
The steeper the slope, the higher the chance of an avalanche. Gravity is a powerful thing, and it alone can pull a massive amount of snow down the hill even without any excessive triggers. What’s more, the steepness of the slope will also affect the speed of an avalanche.
Another thing that can potentially cause an avalanche is deforestation of the terrain. Plant life protects us from natural disasters, avalanches being one of them. Therefore, when we clear a large area of trees, say to create a skiing slope, we leave it vulnerable to avalanches.
Natural or artificial vibrations
Vibrations can cause the weaker layers of a snowpack to fracture. Earthquakes, as well as vibrations from explosions or heavy machinery, can cause the unstable layers of snow to dislodge and swoop down the mountain slope.
All of these factors can contribute to a potential avalanche — on their own or concurrently. Depending on which factors contribute to an avalanche, it can form in two different types.
Explosives are often used by avalanche technicians to trigger controlled avalanches where a threat is identified and they wish to clear an overhang for example.
How avalanches form and the damage they can cause
Avalanches usually form in a distinct V shape, also known as “sluffs.” They occur when the failure layer of snow is near the surface and the fracture that occurs isn’t too deep in the snowpack. These fractures then lead to a rather speedy cascade of powdery snow down the mountain.
Even though they can cause damage — property destruction, injuries, infrastructure damage — they are considered much less dangerous than their serious cousins, the “slab” avalanches.
Slab avalanches are caused by the fracture of a snow layer that’s buried deep within the snowpack. That essentially means that a much more significant amount of snow will start rushing down the mountain.
Imagine the snow sliding off of a roof in a cohesive mass — all at once. A slab avalanche looks a bit like that, except it carries tonnes of snow travelling at speeds of up to 80 miles per hour. With a mass and momentum like that, slab avalanches can cause massive destruction of property, infrastructure, and, unfortunately, even take lives.
As mentioned, avalanches can be of low, moderate, considerable, and high destruction potential. How much damage they cause depends on several factors.
● The position of the failure layer — the deeper the failure layer, the bigger the avalanche.
● The condition of the higher levels of snow — all the layers above the failure layer contribute to the speed and overall power of the avalanche. If they are made out of hard snow that blended into a cohesive snowpack, then they will cascade down in one huge chunk and have a higher destruction power. Slabs of fresh, wet snow, will travel down more slowly than the dry, hard chunks, but they are still cumbersome and will pick up speed if the mountain slope is high enough. Their destruction power is still mighty.
● Slope angle — avalanches usually start on slopes that are under a 350 to 450 angle.
Avalanches have three crucial points — the Starting Point, the Track, and the Runout Point.
● The starting point is the point of the trigger — natural or human-induced. This is where the fracture of the failure layer happens.
● The track is where the avalanche runs down the mountain slope. Depending on the speed, the avalanche can rip out trees, destroy buildings and pick up everything in its path — people included.
● The final point is the runout point. That’s where the avalanche comes to a stop. This is the most dangerous place to be in an avalanche because the snow quickly sets, burying everything beneath it. What’s more, the snow is not only quick to set, but it also sets extremely hard, almost like concrete. This means anyone trapped beneath the snow has little chance of digging themselves out.
So, considering all this, how do we keep ourselves safe in an avalanche? And, if we do find ourselves in one, how do we survive?
Safety and prevention — how to survive an avalanche
So, what’s the best way to survive an avalanche? Simple, NOT BE IN ONE! Yes, we know, that’s not always possible. Naturally occurring avalanches can be unpredictable and you can’t always predict where and when they’re likely to happen. However, some organizations can, and, instead of letting nature take its course, with the potential for not only property damage but the loss of human life, they do their best to prevent these avalanches from ever happening.
Safety starts with prevention
Several techniques can be used to help prevent avalanches. Rangers, ski patrols, and various other organizations employ some or all of them to make the winter season safer for everyone — winter sport-enthusiasts included.
Triggering smaller avalanches
One of the main techniques is to trigger a smaller, controlled avalanche to prevent a big one. Triggering an avalanche can still be incredibly dangerous, so it’s vital that no one is on or around the slopes.
There are several steps to this technique.
- All layers of the snowpack must be analyzed. That’s the only way to determine which layer can serve as the failure layer.
- Explosives are strategically placed to trigger an avalanche. This is often done by dropping the explosives from a helicopter. Artillery fire can also have the same effect.
- If the slope is small, physical pressure can also have the desired effect — skiing or snowboarding over the potential failure points can trigger the necessary avalanche.
Preventing certain avalanche factors from forming
While we certainly can’t influence how the snow falls, the wind direction nor it’s speed, we can divert some factors that contribute to avalanches by building physical obstacles such as fences, nets, and anchors, which can deter, slow down, or completely stop an avalanche from forming.
However, an avalanche is still a tremendous objective concern, even with all the preventive measures in place. Therefore, we should all know what to do if we ever find ourselves in one.
Another great preventive measure is to carry a radio beacon with us at all times while out on the slopes. A beacon is a small device that can transmit signals and alert rescue organizations of our location.
Surviving an avalanche in the open
Move to the side
If you’re on a slope and get caught in the track of an avalanche, the best thing to do, if possible, is to MOVE TO THE SIDE. Avalanches are fastest and deadliest in the center of their downward path. So, while our instincts may tell us to try to outrun the avalanche, we should ignore them and RUN SIDEWAYS. You are never going to be able to outrun an avalanche charging downhill at speeds of 80 miles per hour.
If you are the trigger (which, let’s face it, you probably are) and you are sitting at the very top of an avalanche that’s forming — try to MOVE UP THE SLOPE as quickly as possible.
Always stay on top
When an avalanche catches us, it’s crucial that we do our best to STAY ON TOP OF THE SNOW. That will diminish the chances of getting buried once the avalanche comes to a stop.
Use SWIMMING MOTIONS to make sure the snow and debris don’t drag you down and keep you there. If you can’t swim, or don’t know what movements we’re referring to, for whatever reason, just keep moving and thrash your limbs around to stay on the surface.
Find an anchor
You can weather the avalanche, much like weathering the storm. FIND A STURDY ANCHOR POINT SUCH AS A TREE OR LARGE ROCK, AND GRAB ON TO IT. Of course, if the avalanche is a major one, this won’t help as it will carry your anchor along with you.
Keep one arm up
This might sound silly, but it isn’t. It might be difficult but TRY TO KEEP ONE ARM UP AT ALL TIMES, while riding out the avalanche. That way, if you do get buried, it will be easier for Search and Rescue to find you.
What to do if an avalanche buries you
- STAY CALM.
- DON’T PANIC – if you panic, you will breath quicker, the faster you breathe, the more oxygen you’ll consume and packed into a tight gap in the snow, fresh air will be limited. If you begin to panic, you’ll lower your chances of Search and Rescue finding and saving you.
- DON’T FREEZE.
You will have to work hard to survive, but it is possible. You’ll need a CLEAR and FOCUSED MIND along with the knowledge and good fortune to survive being trapped in an avalanche.
Over 30% of deaths in avalanches are caused by trauma, the rest by hypothermia and asphyxia. Therefore, if you are lucky enough not to have been killed by debris your next concerns should be the air supply and the cold.
If you are completely buried, the chances of digging your way out are slim. However, you can try, but you have to FIND WHICH WAY IS UP, first.
Immediately after the avalanche buries you:
- CLEAR THE SPACE IN FRONT OF YOUR FACE. This CREATES AN AIR POCKET and gives you, literally, some space to breath.
- START SPITTING, watch the direction that your spit falls – GRAVITY will tell you WHICH WAY IS UP.
- Try DIGGING IN THE OPPOSITE DIRECTION, this should increase the chances of Search and Rescue locating and saving you.
Surviving an avalanche in your vehicle
If an avalanche hits the road while you’re in a vehicle, and completely buried:
- DON’T TRY TO GET OUT.
- TURN OFF YOUR IGNITION.
- Try to CALL FOR HELP and SEND YOUR LOCATION.
There’s a chance the avalanche flipped the car a few times, so even if you do manage to get out, you won’t know which way is up. Additionally, a car is much easier to find than a single human.
If the vehicle wasn’t buried completely:
- TRY TO GET OUT.
However, if your escape route isn’t simple, it’s best to stay put.
Surviving an avalanche for kids
Much like adults, kids should be aware of all the rules and tips on what to do in an avalanche. It’s best if children don’t ski alone or far from their adult companions.
Since they are lighter, the avalanche might move them more quickly than their adults. Therefore, it’s crucial that all children learn what to do if they get buried.
If you have a child and are taking them skiing, hiking, or any other activity that might involve an avalanche hazard, make sure you dress them in bold, visible colors. This will make the Search and Rescue’s job a bit easier, as they will spot them in the snow.
A few parting words
Remember — you can’t outrun tonnes of snow. The best you can do when disaster hits is to STAY CALM and think of all possible ways to help yourself.
Avalanches are enormous disasters, but we can survive them. With a bit of luck, proper preventive measures, and training, avalanches don’t have to be a deadly threat.
Stay safe out on the slopes. A big ‘thank you’ to the countless brave men, women and dogs, who risk their lives in order to save ours.
Science of Avalanches
Online Snowmobile safety course
Avalanche Education Centre
Avalanche Statistics & Reporting
Avalanches are becoming more common, thanks to climate change
[Video] How to survive an Avalanche
[Video] World extreme skiing champion: Andrea Binning, Surviving an Avalanche
If you’re a frequent backcountry traveller, plan on going backcountry or would like to know more about avalanches a good option might be to take an avalanche training courses such as those provided by the AIARE