 Poster: A snowHead
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| Quote: |
There is always a personal choice between an acceptable level of risk and the rewards for being in the mountains.
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This captures it in a nutshell. And for "the rewards for being in the mountains" you can substitute almost any other activity. But our perception of risk is notoriously unreliable - or we wouldn't need the sainted David Spiegelhalter - Professor of the Public Understanding of Risk.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| peanuthead wrote: |
From my observations (based on looking at avalanche bulletin for particular resort 1-2 weeks before I arrive so thus may be very anecdotal), avalanche bulletins often, sometimes seemingly invariably, make reference to old snow problems. So it may be understandable that people don't pay enough attention to this, until avalanches start to occur. Presumably there are degrees of risk which is not always conveyed in the avalanche bulletin?
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Well the bulletin can get it wrong of course.
In general the most important current risk(s) are mentioned. The Swiss bulletin for Samnaun mentions "Old snow", the French bulletins for most of the Norther Alps talk about "Persistent Weak Layers" but they are the same thing. Each year there is usually a layer of depth hoar at the base of the snowpack but the problem will only be mentioned if avalanches or shear tests are getting results on these layers (see below)
| peanuthead wrote: |
Another question, that there so many avalanches in Austria and not France, presumably this is because much more snow and hence wind slab in Austria.?. if it is due to old snow breaks, would extra snow not be a protection against skier triggered avalanche? I.e. a falling skier could fracture through 30-40cm of new snow/slab to old weak layer, but unlikely through 1m? Or are there nuances I am missing? |
Yes, although I'm not following the Austrian situation closely. My understanding is over a meter of new snow fell prior to the avalanche.
It has hardly snowed in France since Christmas so although there are weak layers in the snowpack, currently a lot of surface hoar around and buried depth hoar at altitude and north sector slopes there isn't a lot of snow on top of this layer (except in the Mont Blanc area which saw a bit of snow from the weather system that crossed France last Monday).
If the weak layer is deeply buried you are unlikely to trigger it.
However if a meter of new snow falls you will not get a nice even meter of snow across the mountain. Terrain features, wind etc will mean you'll get 50cm here, 150cm there and it is where the snowpack is thin that you risk triggering an avalanche. So there is terrain reading needed on the ground and the depth will evolve all the time with wind eroding or depositing snow.
Regarding bombing slopes, mentioned above, this won't necessarily release an avalanche. There have been cases of resorts bombing the hell out of a slope only for an avalanche to release hours later when someone skis it.
Group spacing, mentioned above, not always that practical for guided groups as the avalanches that break on PWL are typically very large. This appears to be the case in Samnaun where the slide was 400 meters wide. How is a guide going to manage a group of 5 or 6 clients over that kind of spacing, it is not going to work. The only solution is not to make that route choice.
"Alpine start" - this goes back to when spring skiing was the norm and people were mainly worried about wet snow slides, or rockfall for climbers. Typical skier triggered slab avalanches can be triggered at any time and conversely, in the middle of winter it makes little difference if you start at 6am or 3pm with certain provisions. There are plenty of good reasons to start early though.
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You need to Login to know who's really who.
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| davidof wrote: |
| peanuthead wrote: |
From my observations (based on looking at avalanche bulletin for particular resort 1-2 weeks before I arrive so thus may be very anecdotal), avalanche bulletins often, sometimes seemingly invariably, make reference to old snow problems. So it may be understandable that people don't pay enough attention to this, until avalanches start to occur. Presumably there are degrees of risk which is not always conveyed in the avalanche bulletin?
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Well the bulletin can get it wrong of course.
In general the most important current risk(s) are mentioned. The Swiss bulletin for Samnaun mentions "Old snow", the French bulletins for most of the Norther Alps talk about "Persistent Weak Layers" but they are the same thing. Each year there is usually a layer of depth hoar at the base of the snowpack but the problem will only be mentioned if avalanches or shear tests are getting results on these layers (see below) |
Yep, as Davidoff says, the bulletins did mention this and it should have been expected anyway.
Similar to France, Austria (especially western Austria) also had a long period with fresh snow. In steep/cold/shady slopes this will always cause a 'new old snow problem' once it is buried, as surface hoar and faceted crystals develop. The problem was further compounded by a hard rain/melt crust in the old snow - a hard crust(s) with weak snow above and below = perfect conditions for an avalanche (weak snow collapses, everything above it slides on the hard crust). Photos of developing hoar + snow pits showing the problem in this late-Jan blog from the avalanche commission: https://avalanche.report/blog/lawinenwarndienst.blogspot.com/428860530704387388
[img]https://blogger.googleusercontent.com/img/a/AVvXsEgqMLmknbA9ANa1xlwM10FlV6pE-lQ9ClQQiEv9vnDLs4Y6BTkzIc7wBTbPddWKCqn911rSCMj_6OZFlL-8Ye_WcaNXANVkvXdYSHJxpWBGyPDaTTNa2KVV_imtfuHY97PFEeX7B6Hg5rwQ_obFfl4j3ooYH9SqkXR7Nyzy1oC8kXdq0wbWvEt5cNb4Mw=s1920[/img]
[img]https://blogger.googleusercontent.com/img/a/AVvXsEiZfgd-k9KCEQ9k-6McmMdVs-yJUygxVVlF3cpvXnrOwQSG4-h2sDoDqIhLQKw4Q-KzdSGmLjorx83e_f6wosI8ZeP_ULGlx_lvy2xNwXgc9GyGBQuEuChD1A2wDThPwdC86KVbNNSsgidefrGEgUWdPt2tqEBmebA5Yui61Zd8b0iLVPaYax7zaIe_xw=s1920[/img]
As to degrees of risk being conveyed or not, it's probably more degrees of predictability/visibility. If you've got a solid snowpack then get new snow and wind, you'll probably have a danger rating of 3 based on the newly formed wind slabs. That sort of 'surface danger' is easier to recognise and manage while riding than a (often persistent, for weeks/months) danger rating of 3 based on old snow problems buried below the surface.
| davidof wrote: |
| peanuthead wrote: |
Another question, that there so many avalanches in Austria and not France, presumably this is because much more snow and hence wind slab in Austria.?. if it is due to old snow breaks, would extra snow not be a protection against skier triggered avalanche? I.e. a falling skier could fracture through 30-40cm of new snow/slab to old weak layer, but unlikely through 1m? Or are there nuances I am missing? |
Yes, although I'm not following the Austrian situation closely. My understanding is over a meter of new snow fell prior to the avalanche.
It has hardly snowed in France since Christmas so although there are weak layers in the snowpack, currently a lot of surface hoar around and buried depth hoar at altitude and north sector slopes there isn't a lot of snow on top of this layer (except in the Mont Blanc area which saw a bit of snow from the weather system that crossed France last Monday).
If the weak layer is deeply buried you are unlikely to trigger it.
However if a meter of new snow falls you will not get a nice even meter of snow across the mountain. Terrain features, wind etc will mean you'll get 50cm here, 150cm there and it is where the snowpack is thin that you risk triggering an avalanche. So there is terrain reading needed on the ground and the depth will evolve all the time with wind eroding or depositing snow. |
Yep. And the new snow was even more variably distributed than that sort of 'local variation' - some of the Nordstau zones got up to two metres, some inner alpine areas only one valley south only 20cms.
I think this video demonstrates it well (it's from before the recent snowfall) - he was the last of a group to ski an apparently well-filled-in slope, yet you hear him hit a rock (so a thin patch), and then the trigger...
https://www.instagram.com/p/CZQ6BFxpuaK/
| davidof wrote: |
Group spacing, mentioned above, not always that practical for guided groups as the avalanches that break on PWL are typically very large. This appears to be the case in Samnaun where the slide was 400 meters wide. How is a guide going to manage a group of 5 or 6 clients over that kind of spacing, it is not going to work. The only solution is not to make that route choice.
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The analysis is out now: https://avalanche.report/blog/avalanche-warning-service-tirol.blogspot.com/5629503851449789394
I had assumed they were caught on the ascent (as you say, no way to safely manage a group spread out over 4-500m!), but:
| Quote: |
| A group of 6 persons was descending in moderately steep, rolling terrain in a bowl east of Fliesser Berg. They maintained ample distance from each other. In a flattish zone the skier at the head noticed that a large slab avalanche triggered orographically to the right. The skiers tried to rush out of the avalanche path, but no one succeeded. All persons were completely buried in snow. One person managed to free his hand and head and then to alarm the rescue operation on his cell phone. That person was the only one who survived. |
Edit: The avalanche release on the same layer of weak/faceted crystals between melt crusts mentioned above ^^
The terrain in the photos does not look outrageous.
Interestingly they also say:
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| Comparison of the two profiles orographically left of the avalanche shows that the profile taken in the same aspect in flattish terrain was more prone to triggering than that in steep terrain. This can be explained by the thicker melt-freeze crust which was generated over the faceted layer in steep terrain due to higher solar radiation. |
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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It is somewhat ironic that the fatal accidents seem to have involved those who were almost certainly cautious, well equipped, experienced & knowledgeable. The Swedish party engaged the services of an experienced local guide who would have studied the avalanche forecast and used his experience to choose a route, which he had presumably taken many others on in the past, with minimal risk. The couple from Niederau quite possibly grew up in the area and had done the route a number of times over the years. Yet there are many reports of people seemingly ignoring the risks, with little or no protective kit who are still skiing today. For example there was a report from Lech during the week of a young man, seemingly ignorant of the risks he was taking, who was dug out of a slide near the piste despite him having no beacon. Lots of others over the past few days who will, perhaps unknowingly, taken objectively much higher risks than the parties in the report.
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You'll need to Register first of course.
You'll need to Register first of course.
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| Quote: |
Lots of others over the past few days who will, perhaps unknowingly, taken objectively much higher risks than the parties in the report.
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Indeed. They "made a mistake" but got away with it. Whereas somebody who made an informed estimate of an acceptable risk can be killed. I think it's important NOT to say that someone who was killed made a mistake. When my sister's marriage broke down, and she became a single parent, she said the hardest decision to take alone was whether to let her son ride his bike to school. He did the Cycling Proficiency Test, was moderately sensible, etc etc. It was a quiet route, the risk was small, it was good for his confidence and independence. If he'd nonetheless been killed or badly injured it would have been very important that she didn't feel she could "never forgive herself". She took the right decision. He's in his 50s now and rides a motorbike. Rather well!
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From all descriptions I get that they descended on gentle slope however triggered slab on steep adjacent slopes.
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As a keen offpiste skier and tourer, I'm trying to learn as much as I can from each incident.
davidof, thanks for posting links to very good articles, and thanks clarky999 for the incident report - I had not realised it would be released this quickly.
We actually skied offpiste with a guide on the same day and the next one in St Anton. I would say we kept to much safer terrain but I'm wondering - without trying to blame anyone - how something like this could be avoided... Is there anything else more detailed than "don't be there"?
(On a separate point: clarky999, great to see you yesterday!)
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| horizon wrote: |
how something like this could be avoided... Is there anything else more detailed than "don't be there"?
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I'd like to know if there's an answer to that.
With there being this PWL does that mean that line would be off limits till spring?
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| horizon wrote: |
(On a separate point: clarky999, great to see you yesterday!) |
You too! Hopefully we'll manage that again this season!
| horizon wrote: |
As a keen offpiste skier and tourer, I'm trying to learn as much as I can from each incident.
I would say we kept to much safer terrain but I'm wondering - without trying to blame anyone - how something like this could be avoided... Is there anything else more detailed than "don't be there"? |
Obviously purely armchair quarterbacking here the benefit of hindsight, but some initial thoughts and questions (because I'm also thinking about this a lot - and actually there are lots of discussions in various Tirol-based Freeride/skitouring FB groups atm) and no judgements:
1. The area there were in is relatively south and into the main alpine ridge - quite a long way south of St Anton and therefore should have had a lot less snow few snow, which was most dramatic in the more northerly areas
2. The avalanche report for that day did not mention old snow problems (though tbh I would have thought most people would have assumed that anyway) or risks of remotely triggering avalanches
3. The terrain they actually skied seems to have been fairly mellow, but was underneath steeper slopes. A: If they had stayed further skiers left perhaps they may not have remotely triggered (if that's what happened) the steeper slope; B: Had they considered the alpha/beta angle of a potential avalanche on that slope, and if they had been further skiers left could they have avoided being caught?
4. Group spacing. As above it was a 400m wide avalanche and spacing so far while managing the group was likely impossible. But if they had spaced wider, and avoided all being caught, how would/could the outcome have differed?
5. Was the terrain and tour choice reasonable given the conditions on the day? Does it fall within normal/acceptable risk tolerance? Or was it on the bolder end of the spectrum?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| clarky999 wrote: |
3. The terrain they actually skied seems to have been fairly mellow, but was underneath steeper slopes. A: If they had stayed further skiers left perhaps they may not have remotely triggered (if that's what happened) the steeper slope; B: Had they considered the alpha/beta angle of a potential avalanche on that slope, and if they had been further skiers left could they have avoided being caught?
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would anything on the day have made the guide think I'm not hanging left down here because of_ _ _ _ _ _? it looks south facing on the skiers left
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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| Mother hucker wrote: |
| horizon wrote: |
how something like this could be avoided... Is there anything else more detailed than "don't be there"?
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I'd like to know if there's an answer to that.
With there being this PWL does that mean that line would be off limits till spring? |
I don't think so. I think - possibly bar the latest big dump - most would have considered that a reasonably safe/mellow route albeit with exposure from above. Especially if this accident hadn't happened, I can imagine that by early next week many people would have considered it to be a pretty safe option for skitouring (again based only from photos and online guides to the tours in the area). Skiing the slope that actually slid would be another matter.
Terrain allowing (it looks like there's a gully and no idea about exposure from the slope on the other side) perhaps being 20m to skiers left would have made all the difference...
It's also worth bearing in mind there wasn't a PWL until a few days ago - first when it was buried around 31st Jan - and it's only really been the last few days after the subsequent snow that then revealed/confirmed (it was obviously anticipated) just how bad it is.
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| Mother hucker wrote: |
| clarky999 wrote: |
3. The terrain they actually skied seems to have been fairly mellow, but was underneath steeper slopes. A: If they had stayed further skiers left perhaps they may not have remotely triggered (if that's what happened) the steeper slope; B: Had they considered the alpha/beta angle of a potential avalanche on that slope, and if they had been further skiers left could they have avoided being caught?
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would anything on the day have made the guide think I'm not hanging left down here because of_ _ _ _ _ _? it looks south facing on the skiers left |
Certainly possible, but I don't know.
It's probably worth point out that south facing doesn't always mean more dangerous too. Obviously in the afternoon having got sun all day then yes more dangerous, but getting more sun (and potentially melt-refreeze cycle) can also make it more stable earlier in the day before warming than a cold shady 'surface hoar farm' slope...
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You know it makes sense.
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@clarky999, could it have been wind loaded and the guide didn't fancy the south slope?
As a rule North slides more than south, I'm wondering if there was something that made the guide not ski down the left or he just didn't think the North slope was an issue
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Genuinely interesting, thank you.
The comments from local emergency services bosses are very relevant, about folk ignoring firm up to date advice. After all, they put their lives on the line in search and rescue operations.
It’s notable that in many of these incidents entire groups were swept away together, in light of the earlier comment in this thread from poster who knows ‘his off piste onions’ that sections with present danger should be tackled one by one.
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Poster: A snowHead
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@Snow&skifan,
| Quote: |
| Die Ausgangslage für eine Tour in diesem Gebiet war absolut nicht gegeben“, meint der stellvertretende Tiroler Bergrettungschef Stefan Hochstaffl, der mit seinem Hund ebenfalls im Einsatz war: eine 40 Grad steile Rinne, nordseitig ausgesetzt und dazu die aktuelle Lawinenlage |
Short summary: they were skiing in a 40° north facing couloir under acute avalanche conditions...
The head of the mountain rescue was not impressed
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| Steilhang wrote: |
@Snow&skifan,
| Quote: |
| Die Ausgangslage für eine Tour in diesem Gebiet war absolut nicht gegeben“, meint der stellvertretende Tiroler Bergrettungschef Stefan Hochstaffl, der mit seinem Hund ebenfalls im Einsatz war: eine 40 Grad steile Rinne, nordseitig ausgesetzt und dazu die aktuelle Lawinenlage |
Short summary: they were skiing in a 40° north facing couloir under acute avalanche conditions...
The head of the mountain rescue was not impressed |
Steilhang I think you are quoting a comment about the Gammerspitz/Jenneweinrinne* avalanche, which happened on Friday but is a different incident to the one being discussed here. The terrain they skied at Fliesser Berg was classed as moderately steep (that's official EAWS terminology for a slope under 30°), just with steeper stuff above.
*I did that ski tour a couple of years ago, and due to a navigation error we ended up skiing UP the Jenneweinrinne as well as down (definite kick turn training!). I can well imagine that it would have been lethal on Friday. And the Schmirntal is really a textbook cold inner-alpine valley perfect for the formation of old snow problems.
Last edited by Obviously A snowHead isn't a real person on Sun 6-02-22 21:34; edited 2 times in total
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| horizon wrote: |
| We actually skied offpiste with a guide on the same day and the next one in St Anton. I would say we kept to much safer terrain but I'm wondering - without trying to blame anyone - how something like this could be avoided... Is there anything else more detailed than "don't be there"? |
Interesting and important question. We were also free riding yesterday, just a little further along the valley in Galtür. Despite setting off pretty early, the accidents on Friday had been published wide enough that we were all aware of how dangerous the situation was, and it definitely inclined us to be more (very) conservative in terrain choice.
Clearly not everyone got the memo though, as we observed from the lift two snowboarders without equipment heading onto a face of the same incline and similar aspect to one that had obvious natural avalanche activity only 50m away 
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You need to Login to know who's really who.
You need to Login to know who's really who.
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| peanuthead wrote: |
Another question, that there so many avalanches in Austria and not France, presumably this is because much more snow and hence wind slab in Austria.? |
Exactly, it simply snowed more in Austria. The majority of avalanche accidents happen in the 2-3 days following recent snow fall
| peanuthead wrote: |
| if it is due to old snow breaks, would extra snow not be a protection against skier triggered avalanche? I.e. a falling skier could fracture through 30-40cm of new snow/slab to old weak layer, but unlikely through 1m? Or are there nuances I am missing? |
That is smart question, but complex to answer.
In simple terms new snow is additional loading, which makes previous buried weak layers more dangerous. The statement you make about a skier being more likely to cut through a 30-40cm slab is broadly correct. However there are important nuances
1) snow pack is never uniform across entire mountainside. Snow accumulates on ridge lines, gullies, lee slopes etc. It will be shallower in other locations.
2) a single weaker area (known as hot spot) could trigger the entire slope. think of hot spots as like Jenga blocks which can cause a slope to fail.
Now : if the slab gets to 1m deep then notionally a skier is less likely to trigger weak layer below. However see nuances above! A more important thing to be aware of is that temperature at bottom of any snowpack is almost always 0c. Therefore dangerous facets (the weak layer) grow faster during cold weather in thin snowpacks than thick ones.
The fundamental problem with persistent weak layers is they are buried deep in snow pack. This is a double whammy. They are hidden from sight. Plus being buried means they require a major freeze-thaw cycle to transform into stronger crystals.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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| clarky999 wrote: |
| I think you are quoting a comment about the Gammerspitz/Jenneweinrinne* avalanche, which happened on Friday but is a different incident to the one being discussed here. |
I think that one happened since, on Saturday morning. Certainly, I only got wind of it earlier today. I saw that same quote in the TT… unbelievable
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You'll need to Register first of course.
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Seen some mention of 400m wide. Not sure if that was mentioned in one of the reports, from some of the photos it looks considerably less. Perhaps there is a mix up somewhere or the photo doesnt show the upper slope where it was triggered.
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if the slab gets to 1m deep then notionally a skier is less likely to trigger weak layer below.
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It's the classic risk is low, but if it is triggered consequence is huge.
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It’s notable that in many of these incidents entire groups were swept away together, in light of the earlier comment in this thread from poster who knows ‘his off piste onions’ that sections with present danger should be tackled one by one.
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It's one of the things you are taught in any basic avy course. One at a time, and finding "islands of safety" where even if a slide was to occur above you, you should be safe. Definitely something people seem to ignore, not sure why always best to practice the right way of doing stuff and it's not particularly any less enjoyable. Perhaps a bit slower. If you have radios it's a lot easier to manage and can even be beneficial getting some input from below "take it easy the snow is very icy and a bit sharky in the crux", "super stable good snow on the left/right let it rip but avoid the cliff drop it's too big". Also from a non avalanche point of view if someone was to get injured it's much better having people above and below than everyone at the bottom having to hike back up without knowing where the injured person is.
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| Mother hucker wrote: |
| horizon wrote: |
how something like this could be avoided... Is there anything else more detailed than "don't be there"?
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I'd like to know if there's an answer to that.
With there being this PWL does that mean that line would be off limits till spring? |
Generally PWL needs a major freeze / thaw event to consolidate (think rain saturating entire snow pack followed by a good freeze as ideal scenario!). If it stays cold-ish until spring then buried PWL can often remain active for months.
Worst case scenario the danger can often arrive in spring : slopes which previously didn't react suddenly become warm / wet / heavier and suddenly entire slopes can release, often full depth, on previously unreactive PWL. Usually such scenario more common in continental snowpack (Colorado or Canadian interior) than maritime (Europe).
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Unfortunately, this is not the first time that groups of ski-tourers have been caught like this.
Back in 2014/2015 in France and especiually here in the Hautes Alpes there were two separate incidents with the deaths of 13 people, that season was almost double the average.
Here is a brief resume from Anena.
TO CONCLUDE
When you look at the numbers and you compares them to averages, “the year avalanche” 2014-2015 will have been atypical.
The department of Hautes-Alpes was the territory of a number of fatal accidents much more important than what we see
on average (Fig. 3). Above all, the number number of victims is considerable: it amounts to 24, while the average is 6.
Two accidents (Ceillac on January 24 and Pelvoux on September 15) were dramatic, causing alone the death of 13 people.
Hiking (on skis but also on snowshoes) represents more than half of all fatal accidents while the activity usually shares the balance sheet annually in an equitable manner with that of off-piste (fig. 4). The excess of accidents occurred in the department of Hautes-
Alps mainly concerned hikers.
If the trend since 1971 has been rather towards stability, the balance sheet once again demonstrates the high interannual variability of accidents avalanche: 17 fatal accidents and 20 deaths in 2013-2014 against respectively 29 and 45 in 2014-2015.
This variability is directly related to the overall snow conditions encountered each winter. This year, the snow conditions were unfavorable, for a long period ; they consisted probably in the presence of layers brittle persistent, homogeneous over large surfaces, "hidden" in the heart of snowpacks located at higher altitudes in cold directions. These situations particular should perhaps do
the specific warning object to the practitioners. This would allow them without doubt to understand a little better what risk of “large slabs” which goes beyond their usual representations (plates partitioned according to the micro-relief).
I'll never comment on incidents like this as I don't want to invoke an element of karma as it were, there but for the Grace of God etc etc
I've had a very very lucky escape, pinned upside down on a tree and that was after being very conscious of the terrain and dangers above the forest in a dangerous sector, however once in the forest I sort of switched my avy brain off, and that was a classic incidence of a weak layer that I seem to recall Joe Vallone alluded to in a blog and he was right to almost the exact meter in altitude as to where it would be the most dangerous.
Last edited by After all it is free  on Mon 7-02-22 10:12; edited 1 time in total
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| boarder2020 wrote: |
| Quote: |
It’s notable that in many of these incidents entire groups were swept away together, in light of the earlier comment in this thread from poster who knows ‘his off piste onions’ that sections with present danger should be tackled one by one.
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It's one of the things you are taught in any basic avy course. One at a time, and finding "islands of safety" where even if a slide was to occur above you, you should be safe. Definitely something people seem to ignore, not sure why always best to practice the right way of doing stuff and it's not particularly any less enjoyable. Perhaps a bit slower. If you have radios it's a lot easier to manage and can even be beneficial getting some input from below "take it easy the snow is very icy and a bit sharky in the crux", "super stable good snow on the left/right let it rip but avoid the cliff drop it's too big". Also from a non avalanche point of view if someone was to get injured it's much better having people above and below than everyone at the bottom having to hike back up without knowing where the injured person is. |
TBH I think you may both be misunderstanding the news or the nature of this type of avalanche problem, or the terrain in question.
As far as I see, the vast majority of people do ski pitches individually. But that doesn't help much when the whole mountain goes, and it's the nature of this type of avalanche problem that they can propagate (and/or a small slide steps down triggers the weak layer and that then propagates) much more widely than you'd expect.
If we look at the actual example of the Jenneweinrinne being discussed here (it's really more of a gulley than a couloir) there's no question that it was a bad choice of terrain on that day/conditions. But in practise I do not think it is realistic to trat it as a single pitch and ski that whole thing one by one. It's several hundred vertical metres, more than a kilometre long, undulating and full of trees and bushes. You do not have eyesight of the bottom from the top, you cannot see your skiing group member for more than 50 metres or so. You can't see if they crash and need help, you can't see if they trigger a slide, you can't see if they end up in a tree well, you can't see if they go the wrong way, you can't see if they get tired and need a break (which almost everyone would; you'd probably be looking at an hour for a group of 4 to ski that completely individually). Sure theoretically if everyone had radios that would help on the last point but 1. I'm not sure how well radios would work in that tight steep sided valley and 2. they don't help locate your friend who knocked himself out crashing into a tree.
Re. islands of safety, in that gulley there should be some, though relatively few and far in between and quite a way off the logical ski line. But still doable if they were skiing down. But in this case they were skitouring UP and remotely triggered a huge slab above them. From personal experience, ascending that thing takes a good hour; it's tortuous with kick turns every few metres. It is not possible to ascend it as a group maintaining enough distance to avoid all being caught in a slab avalanche AND complete it before dark.
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It feels to me here a little like people are trying to rationalise the risk to themselves. But I'm not sure it really works that way...
From all that I've found out about the Fliesser Berg avalanche, I think the majority of us - including me - would have thought it should be safe and probably have skied it. Apparently the stuff they skied was around 24° - that's the steeper end of a blue run. I think most would have looked at the adjacent slopes and judged the risk of the sliding and running that far across was very low. POSSIBLY there they could have left enough space between members to avoid all being caught, but again you're talking about 500m+ spacing between people which brings other risks. Personally, I think probably the only way to avoid being in a similar situation is to not ski on a day like that - a level 3 day. Probably most of us like to ski powder and so will be skiing on level 3 days. So it's a hard and scary truth to acknowledge... Maybe if you are really determined to minimise the risk as much as possible you could choose to not ski on level 3 days with PWLs. But then you may end up writing whole winters off.
The other avalanche being talked of here is easier: simply bad terrain choice. That risk can and should easily be avoided.
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I admit I wasn't checking and following situation in Tirol all that thoroughly as I have no plans to go to Tirol in next few weeks, but as it's relatively close to my home, I normally check just a bit also surrounding not just exact place where I am. And from what I saw, main problem wasn't wind slab or even amount of new snow (that was pretty damn huge) but about 10cm layer of "hoar" which built in weeks of cold weather with no snowfall before this, and is now buried under new snow, yet it's super reactive. Every snow test from area I saw in last several days collapsed and slide after few strokes from wrist, which is pretty clear sign that should tell you what to do. Yet as Rudi Mair (boss of Lawinenwarndienst Tirol) said, with so many warning, and they were everywhere (TV, radio, Facebook, Instagram, Twitter...), yet there's still so many accidents (50 avi accidents with people involved in 2 days only in Tirol is amazingly huge number).
I'm certainly not person to automatically stay at home when avi level is 4 or even 5, and I had many great days out skiing when avi level was 5, but even at 1 or 2, I check what I can do and where maybe it's not too smart to go. But I still don't get how can you easily walk out knowing there's huge problem pretty much everywhere. Do people who venture out in backcountry really don't bother to read avi report and do their homework before they head out? For those who are "just skiing next to piste" I know this, as I have seen too many until now, who have absolutely no idea things can be super dangerous even if just 10m off the piste (unfortunately I have dig out one dead guy who thought so in past), but for venturing deep into back country I would still think, most people check, but obviously I'm wrong.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| clarky999 wrote: |
| From all that I've found out about the Fliesser Berg avalanche, I think the majority of us - including me - would have thought it should be safe and probably have skied it. Apparently the stuff they skied was around 24° - that's the steeper end of a blue run. |
That rings true
I've never been to that area, so I've never seen it with my own eyes, but I've seen a lot of photos the last few days. I know images can be deceiving – in one of the earlier ones, it looked like a monster that I wouldn't go near, but in some of the other photos that have come out of the avi report, it looked fairly innocuous – I probably would have skied it. At 24°, I'd have expected it to be safe, and the guide must've thought that too.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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@clarky999, I've done a few winters in golden BC so am unfortunately aware of PWLs as it's the norm around Banff (classic continental snowpack). See my post above regarding "risk is low, but consequences if it slides are huge).
I wasn't aware they were travelling uphill, as I said I have not read the reports and I'm going off some not particularly clear/useful photos. My comments about islands of safety were clearly regarding downhill.
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Maybe if you are really determined to minimise the risk as much as possible you could choose to not ski on level 3 days with PWLs.
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Easy with hindsight, but perhaps there were lower risk options that day. Something without overhead exposure, no terrain trap (gulley), something where clients could be spaced better. I'm not suggesting the guide made a bad decision, but perhaps an educational moment for the rest of us.
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| abc wrote: |
| john2 wrote: |
@pam w,
Henry from Henry’s avalanche talks posted a blog a few years ago stating that even if the risk of an avalanche is one in a thousand, you have made a mistake if you decide to take that risk. |
No.
A risk is an uncertainty. If you want certainty, you shouldn't take ANY risk, regardless of the probability.
I think people are confusing risk tolerance with risk aversion. |
abc,
I think the point Henry was making is that if you, as a guide who is in avalanche terrain a lot, keep taking 1 in 1000 risks then over ten years you have a totally unacceptable risk of having you and a group of clients caught in an avalanche. 1 in 1000 repeated a lot is TOO RISKY.
You need to get the risk quite a lot lower than that (say 1 in 10000).
Part of the challenge is that differentiating between a 1 in 1000 and 1 in 10000 risk is hard to do. It needs a lot of technical skill AND MORE IMPORTANTLY lots of conservatism and active management of all the human psychological traps.
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You know it makes sense.
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| ed48 wrote: |
From all descriptions I get that they descended on gentle slope however triggered slab on steep adjacent slopes.
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My understanding is that when there is a PWL you need to be VERY aware of the risk of skiing easy angled slopes that are threatened by steeper slopes because a fracture on your mellow ground can propagate up to the steeper terrain
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| boarder2020 wrote: |
@clarky999, I've done a few winters in golden BC so am unfortunately aware of PWLs as it's the norm around Banff (classic continental snowpack). See my post above regarding "risk is low, but consequences if it slides are huge).
I wasn't aware they were travelling uphill, as I said I have not read the reports and I'm going off some not particularly clear/useful photos. My comments about islands of safety were clearly regarding downhill.
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Maybe if you are really determined to minimise the risk as much as possible you could choose to not ski on level 3 days with PWLs.
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Easy with hindsight, but perhaps there were lower risk options that day. Something without overhead exposure, no terrain trap (gulley), something where clients could be spaced better. I'm not suggesting the guide made a bad decision, but perhaps an educational moment for the rest of us. |
I think the points being made are now getting mixed up about different avalanches, especially with responses to quotes from different people themselves talking about different incidents and then back into general points etc. (including by me)
Fliesser Berg: they were ski touring, with a guide, but were caught on the descent.
Gammerspitz/Jenneweinrinne: local group, no guide, they were ascending.
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Poster: A snowHead
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Anyone knows if they used and deployed airbags? The police report states that they found the incident site by airbag sticking out of avalanche debris.
Also, there was Swedish tv on the site few days later, would be interesting to outcome of that.
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FAQ
