Safer ski touring, fewer avalanches

Stefan Mårtensson

Stefan has worked professionally with avalanches for more than twenty years. Apart from his day job as an avalanche consultant, Stefan is also a researcher at Luleå University of Technology, working towards his doctorate on the topic. “The more I know, the less I understand” is Stefan’s own, humble relationship to avalanches. This is why his favourite season is summer and that avalanches look best on YouTube.

How dangerous is off-piste skiing, really?

With off-piste skiing we can refer to both lift-served off-piste runs and proper ski tours. We don’t know for sure how dangerous an activity this is as we don’t have reliable data on how many skiers actually ski off-piste. However, a good estimate of the risk is the number of deaths: 18.6 per million ski days. This is equivalent to around two deaths per 100,000 ski days, which is a similar level to participating in the Vasaloppet cross country ski race. We do know more about the reasons for the deaths, and avalanches are by far the most common cause of death.

What makes avalanches dangerous?

Out of those swept away by an avalanche, approximately one in every four/five will die, making it more risky than Russian roulette. Russian roulette is “played” with a revolver with a live round in one of its six chambers, the cylinder is spun, and the revolver fired against the side of your own head. As such, Russian roulette implies a deadly outcome in one of six cases, a risk that is still preferable to that of being swept away by an avalanche. If your head and chest is buried, the death rate increases by a staggering 2-3% per minute. Avoiding getting caught by avalanches is therefore by far the single most important issue. If you do get caught, the most important point is to avoid getting buried. Failing that, the last resort is to ensure that you can be found and dug out as quickly as possible.

Avoiding avalanches 1 – become knowledgeable

Almost all avalanche accidents are caused by the skier or someone in their group. In other words, your own behaviour is central when it comes to avalanche avoidance. Fortunately, it seems that even a modest amount of knowledge improves your chances. Examples of such knowledge are the ability to understand an avalanche forecast and being able to correctly judge the angle of a slope. For us ski tourers this is of extra importance, as statistics show that we are more likely to trigger larger avalanches with more burials. To add insult to injury, our decision making and route finding is impaired when it comes to avalanche avoidance during the ascent.

Avoiding avalanches 2 – avalanche problem management

Roughly speaking, an avalanche forecast is made up of two main parts. The first part concerns the current avalanche risk as the more general danger across a larger region. The second part describes the “personality” of the presumed avalanches, such as size, probability, and most likely aspect (altitudes and facing directions). The latter is referred to as “avalanche problems”    and consists of two main types, the first being simple and transient, and the second being difficult and persistent avalanche problems.

An example of a simple avalanche problem is wind slabs. They are easy to spot, they tell you if they are unstable, and various tests work effectively when assessing them. A wind slab usually breaks in close vicinity to the skier, and a resulting avalanche is usually limited in size. In practical terms you can manage wind slabs by being observant for cracks and visible slabs, employing various tests and keeping your slope steepness below 35 degrees.

An example of a difficult avalanche problem is persistent slabs. They’re invisible, usually dead in terms of feedback, and there are no reliable test techniques to spot them. Persistent slabs can be triggered remotely and will usually be large. Persistent slabs are managed by consistently sticking to slopes below 25 degrees.

Avoiding avalanches 3 – understand your brain

A significant contributing factor in avalanche accidents is our brain’s tendency to be lazy and sometimes take short cuts. Six rough rules of thumb to be aware of are contained in the acronym FACETS:

Familiarity: we tend to believe that a given behaviour is correct as we’ve done it before.
Acceptance: we want to be accepted by our peer group
Commitment: we press on in the face of signs telling us this isn’t correct
Expert Halo: we tend to judge expertise on vague grounds, such as age, training, looks and charisma.
Tracks: where we perceive there is a shortage of something, we naturally tend to compete for it.
Social Proof: if someone else has done something, this justifies us doing it, too.

Ensure you’re not fully buried

No off-piste skier should be without an avalanche backpack. Correctly deployed, an avalanche backpack reduces the death rate by half (to one in nine or ten). By tugging on a handle it inflates one or two big balloons with a volume of 150l or more. The skier then becomes a much larger particle and the snow’s motion will tend to push larger particles towards the top of the avalanche. By ending up closer to the surface it is more likely that your airways are still clear, or at least not buried as deep once the avalanche halts.

Enable fast excavation

If all the above points have failed, and someone has ended up fully buried in an avalanche the situation is serious. We have to firstly locate our buried comrade (or comrades), and secondly, excavate them. To locate someone, you need a transceiver and probe. In its default setting, a transceiver works as a transmitter, which can be switched to receiver mode in the case of an accident. Transceiver search is tricky, and needs to be thoroughly practiced both before and during the season. But even so, locating someone is still the easy part. What takes up the most time is excavating someone. To dig someone out fast and efficiently  requires a good shovel, a good methodology and plenty of practice. Prior to any ski tour, all group members should train both search and excavation, to master not just the transceiver but also the probe and shovel before they’re needed.

The idea with transceiver, probe and shovel is predicated on ensuring that the rest of the group aren’t also dragged along by the avalanche. Safe off-piste skiing is therefore a solitary sport where a single skier at a time skis an exposed slope. Downhill, this is usually not particularly problematic: as one person skis, the rest of the group waits in a safe location, either at the top or the bottom of the run. But during the ascent phase of a ski tour it’s much trickier, as the group must maintain distances both horizontally and vertically. As you turn, it’s often the case that you end up in a straight line above or below someone else on the same slope.


The most significant danger when ski touring is avalanches. To be swept away by an avalanche is more dangerous than Russian roulette. In terms of avalanche avoidance it’s vital to understand the avalanche forecast, and being able to judge the aspect and steepness of a slope. It pays to understand your own behaviour as part of a group and to always carry an avalanche backpack. Practice diligently and frequently your use of the safety equipment. Maintain your fitness, too. The fitter you are, the better your decision making becomes, the faster you can run with a transceiver, and the quicker you can dig with your shovel.

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