To risk or not to risk – who is at risk of being caught in an avalanche?

Whenever someone gets killed in an avalanche, it is a tragedy, both for the lost individual, for his or her family, and for society as a whole.

Yes, it is a loss for society, because society looses a person who could have contributed to its development. Avalanche accidents generates costs in terms of rescue actions, health care, destruction of infrastructure and forests.

But let us be honest, the probability of getting caught in an avalanche is still relatively low, and the health benefits that backcountry touring give rise to are potentially very large. So the solution to the problem of people triggering and getting caught in avalanches is probably not to prohibit people from venturing out into avalanche terrain.

So what then is the solution?

Today, avalanche training opportunities are offered by a range of groups and organizations. The structure of these avalanche courses to some extent certainly vary, but courses are rarely tailored to fit different needs of different groups, and most of the material taught is based on the assumption that side- and backcountry skiers make rational decisions that are not affected by factors such as group dynamics, social aspirations, moods and so on.

If these assumptions are not valid, then a restructuring of avalanche courses may be called for, but to know how to do this (and to know if such restructuring is needed at all) we need to test if some groups expose themselves to more risk than others, and why.

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During spring 2017, we launched the first pilot study within the White Heat project. The pilot was a web-based survey, which we distributed via Centre for Avalanche Education and Research (CARE), National and regional outdoor organizations (e.g., DNT), and various backcountry oriented webpages and magazines (e.g., turtrosa.no, turjenter.no, and friflyt.no).

One aim of the survey was to find information that would help us understand if some groups of people are more likely to expose themselves to higher avalanche risk, and why.

A total of 457 people participated in the survey. Of these, 30 percent were women. About 40 percent did not have any formal avalanche training at the time of the survey, but many had a relatively high level of skiing and backcountry experience: 43 percent had more than 20 days skiing on average over the past 5 years and over 80 perce t consider themselves to be skilled or very skilled backcountry travellers.
We measured risk-taking behavior in avalanche terrain in two ways: hypothetical terrain choices and past experience of avalanche incidents.

To create a somewhat realistic setting for the hypothetical choices, we asked the participants to imagine that they were out on a backcountry ski tour with their ski buddies in late March, that they had just reached the summit and were about to make a choice concerning which way they would ski down.

The participants were told that the mountain offered four alternative ways down. Two of these runs were described as relatively safe (no or short sections with slope > 30°, no exposure from above or below) and two as relatively risky (long sections with slope > 30°, terrain trap features). We asked the participants which run they would like most to ski down, given the snow and avalanche conditions, and which runs they would accept to ski given that someone else wanted to ski it.

To help with the decision, we also provided information on both historic and current weather (historic: a big snow fall two days earlier, current: cold, sunny, and bit windy), the avalanche hazard (level 2 – a poor bonding between the new and old snow and a persistent weak layer), and snow conditions (untracked snow consisting of mostly loose powder and, in some places, soft windslabs). These characteristics were the same for all runs.

Now, there are several problems with using hypothetical choices as an indicator of real life behavior: different people may interpret the text in different ways, important information needed to make the decision may be missing, and some participants may answer in a way they think that the researchers want instead of stating their true opinion. Finally, what people think that they would do in any given situation, and what they actually do when the situation occurs, may be two completely different things.

To avoid some of these problems, we asked the participants about how risky they thought that it would be for them to ski down each run (in terms of falling or triggering an avalanche), and we only used answers from individuals who ranked the riskiness of the runs in the same way we did when we designed them. This way, we hoped to avoid treating a choice, which the participant perceived as non-risky, as a risky one. All answers were completely anonymous to avoid that people felt pressured to answer in some specific way.

However, many of the problems with hypothetical choices are almost impossible to deal with. This is why we also asked about the participants experience of e accidents and near-miss incidents.

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These are some of our findings:

It probably does not come as a surprise that we find that the willingness to ride down an assumed risky slope to a very large part depends on how risky we perceive the run to be, and how willing we are to take risks.

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So what then determines how high we perceive the risk to be, and are certain groups more willing to take risk than others?

Our analysis shows that perceived risk depends in part on relatively reasonable factors, such as being good at skiing and handling backcountry terrain. A person who has been skiing a lot has less chance of falling, and possibly greater chance of being able to ski out of an avalanche. It should nevertheless be noted that a slide doesn’t care if a victim is king (or queen) on skis or not.

In part, however, subjectively perceived risk also depends on things shoudn’t affect objective risk. For example, we find that participants, who imagined that they were out touring with someone more skilled in backcountry skiing than themselves, perceived the risk of the steep runs as less risky than participants, who imagined that they were touring with individuals of less or equal skill as themselves. This effect does not depend on the participants’ own self-assessed skill or backcountry experience. We find the effect for all levels of ski experience. Keep in mind that the participants were told that no other information than the one provided by us was available. The only way a skilled touring partner can reduce the objective risk of a run then, is if that person is skilled in terms of rescue, or if she or he skis in a way that minimizes the risk of triggering an avalanche. Remember also that we asked the participants how risky they thought that it would be for them, personally, to ski down the slope in terms of falling or triggering an avalanche. Having a more skilled ski buddy should not affect that risk. Based on the results of this survey, we cannot say what lies behind the correlation between risk perception and having experienced skiers in the group. To know more, we definitely need to study more.

We find several differences in results between men and women. On average, men in our sample say that they are willing to take risks to a higher degree than women in the sample do. The men also perceive the risk of the steeper runs to be lower than women do. This last result is partly explained to the fact that men in our sample have relatively more ski- and backcountry experience than the participating women. However, men in our sample also perceive themselves to be more skilled in handling steep terrain than women do, and they do this even when the number of days and years of skiing is the same. Could this finding explain the fact that we find that men are substantially overrepresented among those with experiences of avalanche incidents?

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When we analyze those who have such experiences, we find that the most important explanation is time in the backcountry, that is, cumulative risk. But men have 30 percentage points higher probability than women of having been involved in an accident given cumulative risk. In other words, we find this effect even if the number of ski days and years of skiing the backcountry is the same.

Finally, we would like to say something differences between most preferred run and accepted run, and about avalanche education. Remember that we asked our participants two questions for the hypothetical choices: 1) which run would you prefer most to ski down? and 2) which run would you accept to ski down if someone in the group wanted to ski it, and no one raised any concerns? A general result that we see is that the participants in our study are willing to accept more risk than they state that they prefer., i.e., their perceived risk of their most preferred run is lower than of the riskiest run that they state they are willing to ski down.

prefer_accept_USA
The Bowl and the Chute has average slope above 30° and are both terrain traps. The Ridge and the Field have average slope under 30°. All participants in the analysis perceive the Bowl and the Chute to be strictly more risky than the Field and the Ridge.

One interesting finding is that while the probability that an individual prefers the steeper runs is the same for people with and without formal avalanche training (level I courses or higher), we find that individuals with formal avalanche training are significantly less likely to accept skiing down these runs. At least in our sample then, it appears as avalanche training does not alter preferences –  those who like steep runs do so with or without avalanche training – the differential effect for accepting to ski a perceived risky run points to the possibility that avalanche training increases the ability to withstand group pressure. However, to know for sure what is causing this effect, we need to study more.

So what should we do with these results? To be honest, our analysis so far has created more questions than answers. During the summer we have revised the survey based on our findings and on the comments we have received from the participants. We are incredibly grateful for these comments. They have helped us a lot. The new survey will be launched in the US during the fall. We look forward to analyzing the new responses.

 

 

 


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