 Poster: A snowHead
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PG, Do those big areas above 2000 often slide?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Just referring to the Lanchettes slide there's some extra info in this thread from almost exactly a year ago.
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The resort tries to limit skiing in this protected area (to the right of the Aiguille Rouge run along the crest as you head down) via a by-law that obliges visitors to either take an accredited guide, or complete an 'awareness' course on the environmental issues of this area, classified as a nature reserve. Within the reserve there are authorised routes. Skiing without a guide or the relevant permit can result in a fine - if caught. The Lanchettes (scene of yesterday's avalanche) and the Grand Col are the only two itineraries allowed.
However despite the hefty fine, some skiers and boarders seem to do as they please. Many use the 5 other off-piste itineraries that are strictly forbidden. A study revealed 1,610 tracks in the Grandes Pentes (up to 150 descents per day), the dangerous S couloir 230 tracks, the Paravalanches relatively few as there is a long climb to the summit to take this route, and finally the "Combe Interdite", with 200 tracks, up to 20 descents per day).
In the two recognised routes there were 7,300 tracks in the Lanchettes, and 5,650 in the Grand Col ...
A grand total of some 16,000 descents over the length of one season (1999/2000), 3,000 on forbidden routes. A total of 257 people had taken the awareness course, lasting a morning and costing some £28, at that time.
32 skiers/boarders, inculding 17 pros, were caught and fined over that winter. 18 have yet to pay up. The majority get away with it because there are only sporadic checks and because they cut through the forest to avoid the areas where there may be resort personnel at the end of the runs.
The reserve was originally set up with the intention of protecting some rare wildlife, including the tetras lyre, a sort of "snow grouse" that builds itself a mini snow igloo to spend most of the winter, only emerging occasional in search of food (buds, pine needles)...
Obviously resort security cannot detonate explosives within the reserve, so after a heavy fall of snow on old snow, plummeting temperatures, and strong winds, yesterday's tragic event was an accident waiting to happen. There were signs everywhere warning people not to venture off piste until the mantle had settled down. It was barely 24 hours since the latest heavy snowfall, and while mountain lore advises two or three days for the new layer to bind, this is only the minimum - it can take longer, depending on conditions.
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Plus this post about the snowpack in general and the Lanchettes route in particular from the book of a local expert:
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Les Clés du Paradiski - The Keys to Paradiski...
There is a superb new hardback book by Didier Givois, high mountain guide, a comprehensive study of the off-piste itineraries around the Paradiski area. It is only available as far as I can see from www.amazon.fr?tag=amz07b-21 - or directly from Didier Givois himself - see bottom of post for contact details). It is written in French, with an excellent English translation. A beautiful work with some stunning photography, detailed descriptions of all the off-piste routes, some chilling warnings, as well as excellent advice. It describes how you should equip yourself, how and why avalanches occur, what to do in the event of an avalanche - both as victim and as witness. As Didier writes, "there is no greater danger than the ignorance of danger."
One description of how the snowpack evolves is particularly apt at the moment, as it describes almost exactly what is happening right now in the northern French Alps in terms of weather and conditions. By all accounts we should allow for considerably more than the standard two or three days before venturing off-piste in certain areas, as things stand......
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Let's look at snowpack evolution in a simplified manner:
The sky darkens and a snowstorm begins. The pretty, star-shaped flakes become entangled while piling up on the ground, their branches criss-cross and they mesh together. Snow can hold onto surfaces that are close to vertical, thereby defying gravity. The layer thickens and then settles under the increased mass. The small crystal dendrites break or sublimate, the meshing decreases, and the snow begins to slide down the steepest slopes, and avalanches are set off spontaneously. The front disappears, the sky clears and the cold returns. At first the snowpack will seem frozen by the cold. But the slightest pressure, sometimes almost insignificant, can break this delicate balance, for example the passage of a skier or snowboarder. Afterwards, the "aging" of the snow will considerably stabilize the snowpack and the risk decreases significantly. A new equilibrium is reached.
However, if the temperatures stay very cold for a long time, the surface snow will remain as powder snow. This is excellent in the short term but more worrisome for the future. The powder snow, when covered by new layers of snow, becomes a fragile layer that can trigger the release of the largest slab of snow. The greater the difference in temperature and/or the thinner the snowpack (maximum gradient), the faster and more marked the metamorphosis: the snow crystals are transformed into small, glass-like particles that cannot connect (plane faces, depth hoar). The layer of snow has no cohesion and becomes very fragile, and any new snow falling onto this layer will be highly unstable (a collapse could be propagated in all directions at the speed of sound). This scenario is unfortunately fairly common in the autumn and early winter when the first snowfalls are followed by anticyclone periods. The cold settles on the shaded slopes of the mountains and weakens the snowpack. This dry snow can affect slope stability all winter long, unless heavy snowfalls trigger large avalanches that clear the slopes to ground level, wiping the slate clean. Conversely, a winter that starts off with heavy snowfalls followed by mild weather bodes well for the safety of freeriders during the season.
Conclusion: the slopes that experience important daily temperature variations stabilize quite quickly, while the others should be looked at suspiciously, even a long time after a snowfall. Avalanches statistics confirm this observation, since 60% of accidents occur on slopes with orientations covering one quarter of the compass dial (NW-N-NE)!.... |
Didier's website www.givois.com is in French, and the order form (and quoted price) is for orders within France only, but he will send the book abroad. You have to email him - info[at]givois.com (replace [at] by @)
His description of the Lanchettes route (predominently north-east facing) mentions that it is not a particularly hazardous descent, when conditions are right, in terms of difficulty - ie a fall would not be too dangerous as the slopes are relatively 'gentle'. However on Didier's avalanche risk scale of 1 to 4, it scores the full 4 for its upper section. It is
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| "located almost entirely on a route with regular avalanches. It includes ... couloirs that channel avalanches coming from slopes that can remain dangerous for a long time." The 'Lanchettes' "is a classic route that sometimes looks like a mogul run! After a heavy fall it must be looked on with a suspicious eye: all of the upper slopes are laden with snow that accumulates under the wind. "Lanche" and "Lanchettes" in local patois means avalanche!" |
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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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As far as Risk 4 plus a guide being safe or not, the only time I have been involved in a major avalanche was in precisely these circumstances, I posted about it here a couple of years ago. We were very lucky no-one was killed, and it just reinforces the point that there is no such thing as safe off-piste and that you should never surrender all decision making to another individual, no matter how qualified he appears to be. Ultimately you have to take responsibility for yourself.
The thing that surprised me about the reports on Pistehors was not that anyone was avalanched (lots of snow followed by rise in temperatures), or even that those affected were guides/instructors/ski patrol (remember: the avalanche does not know you are an expert), but that the burial times were so long even though there were pros involved, wearing transceivers.
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Plake, there's a question mark over this at the moment - my update here last night mentioned that latest reports spoke of probes having to be used to locate the bodies
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According to the PGHM (Peleton de Gendarmerie de Haute Montagne - High Mountain Gendarmerie) although the 2 victims were equipped with ARVAs, teams of PGHM specialists, ski instructors and patrollers using probes, as well as sniffer dogs, were needed to locate the bodies. |
If that report was correct you have to wonder why neither ARVA was giving out a signal that could be pinpointed. Perhaps davidof can suggest reasons for this, other than the obvious...
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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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Close to the same time that Mikey got taken ,yet again more live's are lost on the Lanchette, 40-50 cm of snow in 48 hrs and then it clears , "so hey lets do Lanchette", not a good move or a great idea within a few days of a moderate snowfall,let alone 12 hrs, but unfortunately getting fresh powder and first line's are the holy grail. Personally i'd rather make it back for a beer or two in the evening, the guide should have known better, he probably did ,but pressure to impress clients meant this probably went out of the window. If reports are proved right and it was set of by boarders/skier's above, then i hope they get the book thrown at them, the French authorities have been waiting for this kind of incident to make an example out of somone, and this might be their chance. Taking risks is all part of the backcountry experience , but calculated one's , the buzz is the same, if you want to risk it and kill yourself then go ahead , but risking somone else's life is just selfish and ignorant.
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You'll need to Register first of course.
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I can understand them taking the risk. Surely the blame lies with those above. I presume they had no guide. Off pisting at level 4 without a guide must surely be negligence at the least.
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I've seen several mentions of trees being a 'good sign', that is, making a slope safer. Why is that? From what I've seen on TV (my only experience of avalanches), trees seem to pose no obstacle at all to an avalanche.
Anybody know roughly what happened in Flaine? The old lady's off there on Sunday and I'd like to think that the pistes at least are safe (yes, I know, I'm an old softy).
PS I've now read PG's post on the Flaine thread. It looks like it didn't impinge on a piste.
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richmond, well trees (in a forest, not sparsely located) do indicate safety to an extent - otherwise they wouldn't be there! If they are it's either because avalanches are rare in that area, or because they help to stabilise the snowpack in that particular location.
Coincidentally at the bottom of the classic Lanchettes run in question at Les Arcs, where the bowl meets the forest at around 2,000m, there is a large clearing... caused by avalanches!
Givois's book mentioned earlier rates the avalanche risk for this route at a maximum 4 out of 4.
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"... located almost entirely on a route with regular avalanches. This category includes a large number of couloirs that be definition channel avalanches coming from slopes that can remain dangerous for a long time. Other couloirs don't fall into this category since there level of danger is very limited: they are only affected by a minimal surface area of snowpack and are very narrow, but open up into very large cones that can dissipate avalanches. Before setting out you can also make a correlation between the risk announced by the local avalanche bulletin and the potential risk of the route you are planning..."
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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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Tree's are a good indication of fairly safe avalanche free slope's, basicly due to the fact that they help the snow pack stay attached , the chances of a avalanches point of origin (release point) occuring in a wooded area is very slim, not impossible though. But even so if the slide is released from above the tree line on open slope's and has the potential to build enough power being in a wooded area below isn't going to help much as there is the potential of a slide to demolish trees and flow around them. In saying that the chances of being involved in such an incident are pretty rare nowadays with all the safety management of such area's in resorts.
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richmond, as they say, trees can act as an "anchor" helping to keep a layer of snow in place. On the other hand, in some circumstances, they can create points of weakness in a slab - it's difficult to come up with rules that work 100% of the time. The other thing is that, in theory, you could try to hang onto one if an avalanche is approaching. Whether this works depends very much on the size of the avvy - i saw some (formerly) huge trees in La Grave which had been literally blasted away by a powder snow avvy. Thankfully these are pretty rare in the Alps
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Arno, yes the shock wave preceding a powder avalanche can have incredible explosive power. And points of weakness in a slab can be generated by more isolated trees. This from http://nsidc.org/snow/avalanche/
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Vegetation
On a snow-covered slope, heavily forested areas are much safer than open spaces, but don't assume that any vegetation at all will be protective. Lone trees, bushes, or large rocks on a mountainside can sometimes weaken the stability of the snowpack. A fracture line (the break-off point for an avalanche) may run from a lone tree to a rock to another tree. Also, during avalanches, trees and rocks catch debris and cause excessive snow pile-up, as well as provide lethal obstacles for anyone caught in an avalanche.
Tree line, above which conditions become too harsh for trees to grow, also plays a significant role in avalanche areas. Many avalanches start above the tree line, making high-elevation mountains especially risky. Although forests help stabilize the snowpack, if an avalanche starts above tree line, it can cut its own path, or chute, through the trees below. Likewise, where there is a swath of trees missing from a forested mountainside (and it's not a ski run), there are probably frequent avalanches running down that particular chute.
Smooth surfaces, such as a rock face or grassy slope, may cause avalanches during the spring melting season. On the other hand, if the vegetation is very low-lying, such as tree stumps or shrubs, it can become buried underneath the first few snows and be relatively ineffective at anchoring the upper layers of the snowpack.
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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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Arno, having seen many destroyed trees over the years I'd say you'd have to find one with a trunk diameter of at least 1 ft /30 cms and even then it might not be enough, an avalanche is highly unlikely to start in a stand of trees but it may well start just below such a stand. it's important to realise that every cubic meter of snow weighs arround 100kg so even a small slip of say 50cm depth could weigh several tonnes, a large powder avalanche caused when a cornice breaks off can travel at up to 200kph and weigh hundreds of tonnes, putting it another way, you stand about as much chance of surviving one of those as you do of standing in front of an oncoming express train, after the tradgedy at Galtur at the end of the last century they did tests that showed that the avalanche could force 6 inch dia tree trunks through masonry walls  Your best bet to survive a large oncoming avalanche is probably to get behind a big rock outcrop or a large reinforced concrete structure, better yet take notice of avalanche warnings and don't go off piste for at least 3 days after a heavy snowfall
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D G Orf, yes, although it is important to distinguish between slab avvies and airborne powder avvies. Like you say, the latter move at incredible speeds and have huge destructive power - apparently the one I saw the aftermath of in La grave was caused by a serac fall further up the mountain. Thankfully, though, these are quite rare because, like you say, if you get caught in one you're pretty much stuffed
Slab avalanches are usually less spectacular but are much more common and therefore account for more accidents.
I read an excellent book recently called "Powderguide" (see www.powderguide.com ). It's not as strong on snow science as something like "Staying Alive in Avalanche Terrain" by Bruce Tremper, but it helps answer the vital question of "do i go or not go?" - using simple but powerful (IMO) risk analysis techniques. The first question you need to ask in its recommended techniques is where, on the scale of 1-5, is the published avalanche danger - which reinforces how much everyone should take note of it.
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You know it makes sense.
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| richmond wrote: |
Anybody know roughly what happened in Flaine? The old lady's off there on Sunday and I'd like to think that the pistes at least are safe (yes, I know, I'm an old softy).
PS I've now read PG's post on the Flaine thread. It looks like it didn't impinge on a piste. |
The Gers area is what our US chums would call Back Country. There is or was when I used to ski there regularly no piste as such and is/was served by 1 old very long drag lift.
Also the area was very rarely 'open' and the lift only ran if it was.
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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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..............................
Last edited by Otherwise you'll just go on seeing the one name: on Wed 23-08-06 14:41; edited 1 time in total
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Poster: A snowHead
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| ise wrote: |
| The piste is an excellent black named styx and there's some excellent off-piste as well. |
Yup, certainly is. The Gers bowl is a fabulous off piste area, the SCGB run a number of off-piste weeks in Flaine and the Gers bowl is a good reason to try one.
The question of 'is Gers open today' is never far from the minds of offpisters in the area. Because it really needs the drag to be running to ski, the authorities can control access to it quite well - the opening has to be approved by the head of the local communes of Flaine, Les Carroz and Samoens (I think), so sometimes seems to take longer than you'd want.
You can ski out the bottom if you need to (There's a fantastic restaurant at the end of the lake at the bottom of the combe), but if the drag is closed you'd be mad to try it.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| PG wrote: |
| If that report was correct you have to wonder why neither ARVA was giving out a signal that could be pinpointed. Perhaps davidof can suggest reasons for this, other than the obvious... |
It is possible for a beacon to get damaged or ripped off in a slide - you always want it under at least one layer of clothing and not in a coat pocket or rucksack. I suspect as they were with a guide he made sure they were wearing their beacons properly and had tested before entering the Combe.
Don't put too much weight on press reports. Even the rescue workers at the scene can give confusing accounts.
However accepting what has been reported in some of the press two points come to mind
i. it is standard practise to probe to fine locate a victim unless you want to dig a big hole to find them. if they are buried deeply this can mean probing over a largish area, perhaps several m2.
ii. the rescue services would probe the rest of the slide and use a dog to see if anyone else, maybe not part of the group, was also caught who perhaps didn't have a beacon. The group may not have been aware of other skiers on the slope.
A dog was used yesterday to confirm the location of one of the victims but my understanding is that both beacons were working correctly. I was told that at least one victim was buried quite deeply. The dog used was in training today at Tignes I believe.
Pete is on the ground and may be able to confirm what I've said about the beacons later as a clearer picture emerges.
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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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Thanks David. Yes facts are beginning to emerge. You are spot on about the reasons why a large scale search was initiatied. The delays were nothing like first reported, although the remainder of the initial account is accurate.
A much more complete update.
Key facts to emerge:
Of the three people swept away by the avalanche, the one who was able to trigger the release of his airbag was only half buried, and survived. The other two, who for reasons unknown were unable to trigger their airbags, died.
The avalanche was 'allegedly' released as a result of the passage of a separate group into a 'no-go area', looking for virgin snow by traversing across under a ridge where wind slab had accumulated. They were not accompanied by a guide.
The relatively rapid location of the victims was not enough to save them, as at least one was quite deeply buried. Their injuries are not known at this time.
______________
A terrible tragedy, which apparently once again may have been the result of the thoughtlessness and inexperience of a number of people who ignored the basic rules.
Last edited by Well, the person's real but it's just a made up name, see? on Sat 21-01-06 16:52; edited 1 time in total
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You need to Login to know who's really who.
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ee
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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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Reference the fatal slide on the Combe de Lanchette, French 2 news and various sites are reporting it was indeed triggered by boarders/skiers above , the local police are seeking to press manslaughter charges against at least 2 persons . When will people learn the basics of mountain awareness , is getting that first line really worth it, there is no excuse for such ignorance .
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You'll need to Register first of course.
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busyliving, Not to disagree with you simply to point out that, on average our shop loses around 3 guides a year to avalanches. Nature chooses her victims based on other factors than expierience. Still very, very sad. Thoughts with all their families. 
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I wasn't commenting on the roll of the guide , just a little fed up with those irresponsible persons who will jump in head long onto a itinerary above you with no thought to those below , nature will do what nature will do but this sounds if it was avoidable with a little thought and caution , no offence mean't.
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THis worries me. In years past, thew whoel learning experience took a lot longer, and in the process of learning to ski, people picked up at least the basics of piste etiquette and maybe a smidgeon of mountaincraft. with the introduction of sidecut skis and snowboards, the learning curve in terms of skiing has been rapidly acceleretaed - with the inevitable consequence that the piste etiquette etc is less likely to be learnt. "fresh tracks" is the holy grail - and I don;t discount myself here, I know that I've been guilty of goign where I maybe shouldn't have as recently as this week. I just woinder where it's all going to end - are we going to head towards having a "piste licence" to show you can ski, and maybe an "off piste" licence to show you know what you're doing (and more importantly won;t endanger anyone else) when you want to get a bit more adventurous?
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You'll get to see more forums and be part of the best ski club on the net.
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nbt, Love the licence idea, it would kill Chamonix, however i'm sure save lives. I think a piste licence too, colour coded as to the type of piste access.
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colour coded as to the type of piste access.
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Wouldnt this be difficult to enforce.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Linds, Not with the kind of magnetic passes we now use, even if it stops a few it could help.
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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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| SMALLZOOKEEPER wrote: |
| Linds, Not with the kind of magnetic passes we now use, even if it stops a few it could help. |
I suggested this after my friend was wiped out by an out of control skier on a pretty easy red run.... (Le Tour)
the french I was talking to look aghast at the idea..... I still think it could work a bit....
Pretty horrified at the "I've been skiing a year but I only ski off-piste" brigade down there.... & the one that boasted she had never had a lesson - but again only skis off-piste (guess what nationality both were?)
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..............................
Last edited by So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much  on Wed 23-08-06 14:42; edited 1 time in total
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You know it makes sense.
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Just read that. Got the hairs on the back of the neck right up.
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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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Poster: A snowHead
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..............................
Last edited by Poster: A snowHead on Wed 23-08-06 14:42; edited 1 time in total
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Whoa!. thats effectively a witness statement that will be admissable in any future enquiry to the circumstances of this instance.
Good citizen journalism!!
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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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hibernia, it's a remarkable insight, it's good of the author to take the time to share it with us all.
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You need to Login to know who's really who.
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"swim" in an avalnache- like treat it as 'liquid ' untill it sets kinda thing? What sort of movements do you do 
I was plannign to do an introduction to off piste, but increasign nightmares about avalanches etc have put the fear at RED ALERT .
How much are these air bag things? Anyone else use them?
sorry-about these simple quesitons..
vis
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FAQ
