 Poster: A snowHead
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This phrase gets bandied about quite thoughtlessly on here but this is an illustration that as soon as you step off piste, you start having to make your own judgements:
Be safe out there!
(and no, I don't know where that is)
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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looks a bit man made to me
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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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You need to Login to know who's really who.
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Sobering! That's a big slide 
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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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rayscoops, what makes you say that?
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If the pisteurs had done that wouldn't they have started it at the top of the slope?
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Good point.
Where's that in the photo?
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Yep I guess at its closest that's under 5M from the edge of the piste, interestingly it actually seems to show something I suggested in a previous post, the piste marker poles seem to have been placed down the line where the piste slopes slightly to the right whilst the off piste slopes slightly to the left, I suggested previously that this might be why the piste was safe when adjacent off piste was not
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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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Arno, well if i was taking a picture of an slide I would have taken it including the displaced snow = the interesting bit is suppose, also the angles and lines of the break are quite sharp and mechanical and the angles of the bit to the left look a but manufactured. I would not be surprised if it was unstable snow that had been 'forced' to avalanche maybe, which perhaps gives me the impression that it is a bit man made. who knows, maybe someone can verify it becasue it is quite striking
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rayscoops, It could be avalanche training and thus man made but I do not think it necessarily looks madmade. If you look at the striation scratches these are very consistant with an avalanche/moving snow plate. Also look at the crowning which again looks consistant with natural fracture of a snow body.
I wouldnt be too concerned with the lines being quite rigid as physically this is more probably than wiggly lines, The reason for this is that generally lines of weakness occur due to allignment of weaker molecules with stronger molecules and most minerals bar glass have linear molecular patterns.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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plectrum, obviously the snow has moved in a natural manner and not been dug out, but was it cause by a skier? I would have thought there would be more scars at an angle to the left side of the slide because there is only one direction a big section of the snow to the top left of the picture would have gone and that is diagonally from left to right, you can see a bit of the soft snow on the left I suppose. Maybe it has been cleaned up after a mini avalanch, I do not know
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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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rayscoops, I think on consideration that if the snow is quite fresh and recent and hasnt gone through periods of melting and freezing then the alignment of the crystals will be structured and neat as it. But if the pack has undergone many stages of melting and freezinf then you will get a reworking and interlocking and overlapping of crystals/fibres hence potentially mroe stable but also if it does break it will break along many intertwined planes and so more a haphazard irregular fracture plane. In this case it looks as if it was fresh, but I also think it could be man initiated for avalanche training...
BTW is this like a pub quiz where Arno will tell us at the end of the week what happened next!
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Any estimates of the angle of that slope?
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You know it makes sense.
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rayscoops, I am not sure it has been cleaned up. To the left it looks like the top of the camber and so there is little incentive for the snow to fall away from left to right. This is why I think there is a bit of fluff snow deposited there and then as soon as you move to the right the dip develops and so the snow runs off.
I also like the skier in the photo by the piste pole, he is looking down thinking.... woo thank fuk I decided not to go for a bit of piste side powder!
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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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Arno - thanks for posting that. Very sobering.
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Poster: A snowHead
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pam w, It is very hard to guess from the photo as it depends on the angle of the photographer to the slope ... but isn't 30 degrees always a good guess! The strange thing is that this patch has been skied loads by the look of all the trails.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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after a wee bit investigation i found this...
Une plaque est toujours en embuscade même aprés plusieurs passage, comme dans ce cas extreme, sur le coté d'une piste balisée.Un hors-piste completment "damé" (trafoler) à été le théatre du détachement d'une plaque de pratiquement un métre d'épaisseur.Sur la photo, la plaque semble avoir glissée sur du givre de surface.
anyone able to translate?
file is from here
http://www.camptocamp.org/images/110094/fr
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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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Here's Google's attempt...
"A plaque is still in the same ambush after several passage, as in this case extreme, on the side of a runway balisée.Un off fully "damé" (trafoler) has been the scene of the detachment with a plate almost a meter thick. In the photo, the plate seems to have slipped on the ice surface."
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PhillipStanton, erm, come in davidof!
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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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One other significant thing this photo illustrates is the folly of thinking that a slope is safe if it has been skied.
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I think:
A well skied slope is still at risk of a slab avalanche, as in this extreme case, beside a marked piste. An off-piste well compressed slope was the scene of a slippage of a slab almost a metre thick. The picture shows the slippage which seems to have been on an icy surface.
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jbob, yes, it is an eye-opener.
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I guess it depends what we mean by "man-made" - ie set off intentionally, or set of by accident by a skier. I suspect the latter but we'd probably need to find someone who saw it happen to confirm.
I think what the caption is saying is that a slab can still be released after several people have skied over it and the photo is an extreme example, right next to a marked piste. The off-piste was completely tracked out but was the scene of the release of a slab almost 1 metre thick. In the photo the slab appears to have slipped on an icey surface.
Aside from how tracked out it was by the time it released, I think it's a very good example of how a slab avalanche works. You need a slippery surface (maybe refrozen snow or faceted snow crystals) which doesn't allow new snow to bond with it then a build up of a slab on top. Somewhere on the slab is a point of weakness and you just need something to put stress on that and the whole thing releases. That sort of crown (ie quite neat looking) is pretty characteristic for slab avalanches. It's different for "point release" avalanches which you get with powder or wet snow
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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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| achilles wrote: |
I think:
A well skied slope is still at risk of a slab avalanche, as in this extreme case, beside a marked piste. An off-piste well compressed slope was the scene of a slippage of a slab almost a metre thick. The picture shows the slippage which seems to have been on an icy surface. |
Actually, I'm sure you're right, I was just being lazy! Also I was thrown by 'embuscade' thinking it was some sort of technical term: in fact it's just saying, rather colourfully, that one can be ambushed by an avalanche!
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brian
brian
Guest
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If it cheers anyone up at all, the Swiss avalanche service is reporting that this season so far, a generally favourable snowpack has formed and the current risk across the Swiss alps is 2 (Limité) or 1 (Faible).
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Arno wrote: |
I guess it depends what we mean by "man-made" - ie set off intentionally, or set of by accident by a skier. I suspect the latter but we'd probably need to find someone who saw it happen to confirm.
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it has not been triggered by explosives AFAIKS. I seem to remember seeing that picture posted somewhere else recently.
There is a lot of "givre de surface" (surface hoar frost) around at the mo in the 1200-1600 level, something to watch out for after the next slide. There was also some graupel (like small ice balls) deposited a week ago during the storm although I don't know if this made it to Italy.
Good post Arno. Note that the off piste is very well tracked.
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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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May i point out the proximity to the piste, it's not just off the piste we need to be aware of danger.
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| davidof wrote: |
it has not been triggered by explosives AFAIKS. I seem to remember seeing that picture posted somewhere else recently.
There is a lot of "givre de surface" (surface hoar frost) around at the mo in the 1200-1600 level, something to watch out for after the next slide. There was also some graupel (like small ice balls) deposited a week ago during the storm although I don't know if this made it to Italy.
Good post Arno. Note that the off piste is very well tracked. |
x-post from TGR which was an x-post from camptocamp
good bit of french vocab for me to remember (givre de surface = surface hoar)
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You know it makes sense.
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| Arno wrote: |
good bit of french vocab for me to remember (givre de surface = surface hoar) |
as opposed to: pute de surface - surface whore 
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brian
brian
Guest
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Poster: A snowHead
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The most worrying aspect for me is that it looks like it had already been regularly skied, see all the surrounding tracks leading onto the slide area  It looks like black marker poles so I guess it is a steep pitch..
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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what altitude is it at?, does the reference to a slippage on an icy surface suggest the piste is at a glacier? I saw similar slips all over Verbier in the last few days (whereby the mountain was exposed right down to the grass) in quite a few big areas, but the snow had slipped like a big folding blanket rather than a rolling mass of snow, in some cases maybe 30 meters from the piste, but generally on steep and wide expanses of the mountain.
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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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Ooooo............have read the text now - it's the mark left by an avalanche, that explains the reference to 'slip' in my question about the piste patrol as well. I've not seen this sort of thing before. I know the photo's been taken from a distance away, but the layer of snow that's not there doesn't seem as deep as I would have imagined. I wonder how far it moved and whether it interfered with the piste further down if the piste swung towards it.
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You need to Login to know who's really who.
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N.B. Think I'll be sticking to the piste!!
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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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Megamum, much more dangerous on the piste with these slides slipping across them and boarders buzzing around 
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brian
brian
Guest
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davidof, thanks, very interesting.
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nice photo, big slide so close to the piste, mustve been scary if anyone was around when it went
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