SnowFlurry

SnowFlurry 20 2016/17 | Werner, we have a communication problem!

Honey, let's talk about the old snow problem and danger levels.

by Lukas Ruetz • 03/16/2017

The tiresome issue of human error with the old snow problem remains - just like human error with the danger levels.

Initial situation

The SnowFlurry is a column - although scientific principles play a major role, they are subordinate to the opinionated nature of a column. Today's occasion: The avalanche accident with four fatalities on 15.3.2017 on the Jochgrubenkopf near the Brenner Pass: It is a steep to extremely steep north-facing summit slope between 2100m and 2450m. Analysis by the LWD Tirol.

The communication problem, first part

No matter whether the overall situation is classified as Moderate, with its definition "The snowpack is only moderately consolidated on some steep slopes, otherwise generally well consolidated. Avalanche triggering is possible, especially with high additional loads, particularly on the steep slopes indicated. Large spontaneous avalanches are not to be expected." or Considerable: "The snowpack is only moderately to weakly consolidated on many steep slopes and avalanches can be triggered even with low additional loads. Occasionally, some medium, but occasionally also large avalanches are possible." The slope on the Jochgrubenkopf was exactly in the area where the snowpack was known to be not well consolidated at the time.

Today's opinion: the snow pusher believes that the accident would not have happened if the danger level on that day had been "Considerable" and had been stated in the situation report (which, however, would clearly not have corresponded to the prevailing overall avalanche situation). If, for example, the snowpack on the sunny side had already been more soaked and a previous cloudy night had hindered the radiation, a danger level of Considerable would have been quite possible in this area and at this altitude. Although nothing would have changed for the north-facing slope of the accident.

As always, it's not about apportioning blame. The upcoming trial against the surviving mountain guide also makes no sense because the group, if the above assumption were true, acted in exactly the same way as the majority of winter sports enthusiasts do - too much oriented towards danger levels, too little oriented towards information. Besides, the penalty is already big enough.

It's about our communication problem in applied avalanche science. The layman - including many mountain guides - does not understand the situation report sufficiently and cannot apply it. If you have a driver's license, you can't yet drive a car well.

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Well, how should one thenapply at present? Thousands of north-facing steep slopes at this altitude have been skied in recent weeks and almost nothing has happened. The probability of triggering is low and only conceivable in very, very few, snow-poor, previously untracked places, the required load is very high. So just drive in and hope you don't get caught?

Not a permanent solution either

(Computational) reduction methods are of little or no use to those who know little or nothing about the background. An external employee of a German-speaking avalanche warning service formulated the use of reduction methods as follows: "The Snowcard, for example, is an attempt to counter a complex problem - in this case avalanches - with simple means. This may well work for the layman on moderate tours in the majority of cases. In special cases, such solutions fail." He continues:

"In an increasingly complex world, people are longing for simple solutions. Result: Trump or, in the case of snow, Snowcard, Stop or Go. Everything may be right at times. But such simplistic views hardly offer any lasting solutions."

In Sellrain there is a similar problem child as the Jochgrubenkopf: the Zischgeles, the normal route runs through a very steep to extremely steep, mostly snow-covered north-facing slope, altitudes 2400m and 2800m. There have already been dozens of avalanche deaths here due to an old snow problem. The usual, snowy ascent and descent corridor (around 35° steep) in red, the low-snow trigger area in most cases (approx. 40° steep, blown-off ridge) in green. The snow slab then breaks over the entire slope, even the previously heavily tracked areas break with it. Photo taken on 15.3.2017 - according to the LLB, the old snow problem is still an issue on very steep north-facing slopes above 2200m. Despite the time of year, the snow flurries still don't dare to enter this slope due to the areas with little snow. — In Sellrain there is a similar problem child as the Jochgrubenkopf: the Zischgeles, the normal route runs through a very steep to extremely steep, mostly snow-covered north-facing slope, altitude 2400m and 2800m. There have already been dozens of avalanche deaths here due to an old snow problem. The usual, snowy ascent and descent corridor (around 35° steep) in red, the low-snow trigger area in most cases (approx. 40° steep, blown-off ridge) in green. The snow slab then breaks over the entire slope, even the previously heavily tracked areas break with it. Photo taken on 15.3.2017 - according to the LLB, the old snow problem is still an issue on very steep north-facing slopes above 2200m. Despite the time of year, the snow flurries still don't dare to enter this slope due to the areas with little snow
.

Lukas Ruetz

Zischgeles (not: that, but: the)

Risk management in all situations - including in the winter sports months before and after the period covered by the situation report - with really good decisions can only be made with a massive amount of time spent on theory and, above all, the implementation of snow and avalanche knowledge. However, hardly anyone can or wants to take the time. Understandably, snow and board sliding is only one part of life and only the central part for very few people. What's more, if you like powder skiing, you don't necessarily have to be interested in snow and avalanche science - the correlation here is only moderately pronounced, not directly proportional.

If you're only out and about at the weekend and otherwise have another job or a family to look after, it's not possible for you to get to grips with the theory and winter/weather conditions to such an extent that you can work properly in the terrain. If you travel a lot, you have almost no choice but to become a self-proclaimed nivologist - in conjunction with defensive behavior in certain situations. The only way to compensate for this is to make use of the excellent information provided 24 hours a day, 365 days a year by those who are personally passionate about it: Studeregger, Rastner, Konetschny, Schweizer, Reuter, Mair, Nairz or whatever their names may be.

What do you do when the probability of triggering and spread of danger spots is very low, as is the case with the still prevalent but already largely subsided old snow problem? Either hope that you won't encounter such a spot, or know that you won't encounter such a spot, i.e. go somewhere other than above 2200m, steep, north, with little traffic and little snow.

And what are the danger levels good for?

Well, quite a lot too, but only for a quick overview! But only if you know their definitions, you know that a danger level is an average value for the overall situation in an area for all exposures and terrain formations. A hazard level can never be defined for a slope or a small area. For example, slopes in certain exposures are dangerous, slopes in other exposures are safe. And they are right next to each other, making it difficult for our brains to comprehend. Even alpine quality media post on Facebook: "On tour with moderate avalanche danger (avalanche warning level 2) and perfectly equipped - and then run into a real monster. The mountains remain unpredictable, especially in winter!" - People, stop thinking primarily in terms of danger levels, please. They are not made for this purpose!

... would this change anything in your tour planning?

The communication problem, second part: Two is not equal to two, three is not equal to three - an example

Situation 1: High winter, 30cm of fresh snow, cold, moderate, strong north-westerly wind in ridge areas, no weak layers in the old snow. The danger level is issued due to fresh drift snow that is very easy to disturb, especially on leeward slopes (mostly south, southeast and northeast slopes). There are enough danger spots in terms of number and the fresh, brittle drift snow in these is so easy to trigger that the situation fits the definition of the danger level exactly. It is most dangerous near the crest and high up.

Situation 2: April, classic spring situation, good night-time radiation and superficial consolidation. The danger level Considerable prevails in the afternoon due to the daytime warming. Eastern slopes become more dangerous first, followed by southern and western slopes from later in the morning. North-facing slopes at lower altitudes may also be affected. There is also spontaneous avalanche activity. Depending on the time of day, it is most dangerous in various exposures and especially at lower altitudes. The definition of the danger level also applies here in the afternoon.

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These two situations have nothing to do with each other, despite corresponding to hazard level 3. It is dangerous in completely different areas in each case and sometimes safe exactly where it is scorching hot in the other "threesome". This spatial variability with regard to the distribution of danger spots and the variability in the required trigger load is most pronounced at hazard levels 2 and 3. The variability is lowest at Low 1 ("it is safe almost everywhere") and Very high 5 ("it is very dangerous everywhere") and only slightly pronounced at hazard level High 4 ("it is very dangerous almost everywhere").

A self-experiment for everyone: First ask someone to cut out only the text part of the situation report so that you can only read the text yourself, without colors or pictures. All literal descriptions of the danger level should also be removed from the text section. This is how you define your tour destination. Then read the complete situation report with the danger level. Has the tour planning changed? If so, you should question yourself...

Note: The highest priority is the distribution and necessary trigger load of the danger points. The danger level is only a summary of the points mentioned; on its own, the level has the same effect as a touring ski without skins - only on the piste.

This article has been automatically translated by DeepL with subsequent editing. If you notice any spelling or grammatical errors or if the translation has lost its meaning, please write an e-mail to the editors.

Show original (German)

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