 Poster: A snowHead
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Hi guys.
So something has been puzzling me, I've heard a few theories but would like to hear a few more!
Why do very flat runs tend to develop bumps(like sleeping policemen) very close together, making the slope into a sort of seascape?!
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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magicrichard, good question!
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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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Let's have the theories you've heard first 
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I reckon it is caused by skis flexing.
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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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its magic
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You'll need to Register first of course.
You'll need to Register first of course.
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Snowboarders scraping all the snow up into piles?
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| magicrichard wrote: |
very flat runs tend to develop bumps |
 I checked the date of this posting but April 1 has still to come. I must be missing something.
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| ccl wrote: |
| magicrichard wrote: |
very flat runs tend to develop bumps |
I checked the date of this posting but April 1 has still to come. I must be missing something. |
I think ridges is a better description, where they run across the width of the piste or the track, rather than bumps which are discrete mounds of snow.
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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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the bumps are normally near the end of runs, or junctions etc. that are natural places to stop usually, and they are caused by skiers stopping (in the same place each time) to check where their friends are etc., turning their skis parallel to the run and forming, each time, a slight bump across the narrow flat piste. It just builds up (like moguls do due to skiers cavrving their figure of eight turns) over the course of the day in to small bumps
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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It's burrowing snow snakes.
Be aware of these fiendish creatures, they have a habit of popping out of the snow, grabbing an edge and tipping you over on simple green runs, in front of loads of people and then disappearing again 
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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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Marmotte tunnels?
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I think bumps on narrow flat bits of piste are caused by people having to quickly put in lots of wee turns or snowploughs to control their speed, as so many people get shoehorned into a narrow piste that it can get busy and you will often have to slow down or quickly change direction to avoid running into the back of someone.
Like 'braking bumps' on mountain biking trails caused by people unnecessarily pulling their brakes on.
Oh, and on completely flat bits, bumps are possibly made by people 'skating' their skis. Maybe
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You know it makes sense.
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None of the above look remotely convincing to me. Maybe it is the result of a process rather similar to the "soil creep" which can cause very similar ridges on sloped pasture land, depending on the depth of soil and nature of the soil/rock interface. Maybe because of the local logistics piste bashers always run the same way on some stretches, and so do skiers. So the effect is a little like running the flat of your hand up a bottom sheet on a bed - try it.
There were some good ones in LDA near the glacier in the summer, I seem to remember.
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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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pam w - naaahhh - simply the repeated pushing of snow in the same location in some manner by skiers
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Poster: A snowHead
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Surprisingly, the answer is sleeping policemen, or gendarmes couchants as they are known in France. It is a little known fact that unlike our native English breeds, most continental rozzers hibernate. Left to their own devices, they will naturally drop off into a deep sleep in their own beds (or, preferably, that of the Chief Super's old lady, but that's another story), having put on a few pounds (or kilos, as they prefer to call them) by eating huge quantities of high fat salamis, paid for by the sppeeding fines collected from tourisits during the fertile summer months. However, to avoid wasting their potential for being a pain to one and all, as the snow flakes egin to drift down out of a leaden autumn sky, their colleagues remove from their beds and lay them across otherwise flat pistes. The first snow storms cover them up, dropping their already low metabolic rate further, and there they lie until spring, making unsuspecting visitor's lives a misery. In mid April they awaken, stretch and head for the valley floor, ready to grab their mobile speed cameras (and possibly the Chief Super's old lady) to begin the cycle once more.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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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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rayscoops is right.
The ridges, or 'white waves', found on flat pistes are caused gradually by mounds of snow piling up as riders snowplow, parallel or slip their way down the slope.
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| Whitegold wrote: |
rayscoops is right.
The ridges, or 'white waves', found on flat pistes are caused gradually by mounds of snow piling up as riders snowplow, parallel or slip their way down the slope. |
This is what is puzzling me. Are we talking about flat ground or are we talking about a slope?
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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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ccl, They appear on very shallow slopes 0r on flat ground that are used as run outs from steeper slopes
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riverman, yip, and interesting to ride on a board 
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My theory: A bit of soft snow causes a delve in the piste . As skiers drop into this they make it deeper. as they rise to the top they become lighter as they crest the brow and heavier as they come down again. This causes a ripple effect. I presume a similar effect is what caused the boarder cross in La Ros to become more mental as last week progressed . 
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Frosty the Snowman, I think you could be on to something there.... the ridges/bumps are almost like waves... so might be formed in a similar way.... and the continuous flow of skier traffic over them makes them bigger and bigger as the day goes on.
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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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Fascinating. In all the years I have been skiing I must have gone over these things many a time without a thought. Something to look out for next season, then.
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ccl, I'm much the same, although I had started wondering why a few weeks ago.
Whilst rayscoops' suggestion is eminently logical I don't think it's right (or at least not wholly) as these ridges sometimes form on tracks too narrow for snow-ploughs, turning or stopping, and most of the time on runs which are so shallow that no-one would be daft enough to stop there (would they?).
I like Frosty the Snowman's idea, although I have no idea if it's right or not.
Slightly off topic (though relating to an earlier comment), we had a skate race just before lunch on my course today. Good fun it was too (no poles allowed).
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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ccl, you've never seen them really? common on green runs - roads back to resort. they're quite pronounced - they bounce you up and down unpleasantly - a filling shaker
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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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Oops, just reading red 27's comment made me realise that I only half read ccl's. To clarify, I knew I was skiing over them, I've only just started wondering what on Earth causes them!
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I buy rayscoops, explaination. Just try following some kids down one of those tracks through the trees that the ski school makes, After a while, it is nothing but waves from continuous snow ploughs/
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You know it makes sense.
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| red 27 wrote: |
| ccl, you've never seen them really? common on green runs - roads back to resort. they're quite pronounced - they bounce you up and down unpleasantly - a filling shaker |
Well, I must have seen them; but I obviously can't have noticed them. Must be absorbing them without thought. Let's put it down to good technique. 
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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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I'm with Frosty the Snowman on this one. Follow this link explaining how moguls are formed by snowmobiles -
http://www.sno-pals.com/images/mogul%20formation.pdf
snowmobiles do not snowplough, skid sideways etc but just go straight and still cause moguls. The snowmobiles have suspensions, skis have flex and the skiers weighting/unweighting. Maybe it needs a slight trigger in the snow like a soft spot, an existing bump caused by skidding skiers. Someone needs to setup some timelapse photos at a know flat(ish) bump spot and post on here. Subject matter for a university research grant? EPSRC here I come.
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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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| Frosty the Snowman wrote: |
| My theory: A bit of soft snow causes a delve in the piste . As skiers drop into this they make it deeper. as they rise to the top they become lighter as they crest the brow and heavier as they come down again. This causes a ripple effect. I presume a similar effect is what caused the boarder cross in La Ros to become more mental as last week progressed . |
I'm with you on this one.
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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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waynos, I tried googling yesterday but didn't find anything immediately, and moved on. But you've definately hit on the answer there... It would appear to be a variant of what appears to be described as washboard road, where the same thing happens on dirt tracks (or any surface made up of small particles!)
http://www.gi.alaska.edu/ScienceForum/ASF18/1815.html
Quote:"the road surface had to be non-rigid, it had to be dry, and washboard forms immediately after an irregularity in the road surface, such as a bump, dip or small rock.
Bumps in the road surface cause the tire to hop in the air. Where the tire crashes down, it forms valleys by spraying sand and gravel forward and sideways. The moving tire ramps out of the valley and hops again. Thus, the washboarding process repeats itself.
Washboard spreads across the road as other cars repeat the action of the car that initiated it"
So, Frosty the Snowman, it looks like your theory is correct!
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You need to Login to know who's really who.
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I think it happens in a similar way to the movement of sand dunes (see pam w's theory), where the skis push the snow in the same way as the wind moves the sand...
... this is then compounded with the widely acclaimed 'Frosty the Snowman' ripple effect theory...
... thus creating the perfect habitat for the 'burrowing snow snakes' (recently discovered by Sarge).
Never let it be said that skiers don't do their bit for the environment
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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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Phew - that's cleared that up then...
Next mystery to be solved is why do button lift sometimes pull you up so hard it feels like the seat is gonna get yanked right through you like an apple-corer, and sometimes not? Not moaning - I quite like it, but why?
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red 27,
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red 27, La Rosiere has the best drag lifts for this. One of our lady companions described one particular harsh one as: "like having a pull through with a christmas tree"
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Whatever floats your boat, red 27. You're obviously a candidate for the button lifts in the Arly Valley, which are particularly challenging. Worse than the La Rosiere "nutcracker".
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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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| Frosty the Snowman wrote: |
| red 27, La Rosiere has the best drag lifts for this. One of our lady companions described one particular harsh one as: "like having a pull through with a christmas tree" |
Know that one!! The drag to the right (facing uphill) of the main Roches Noir (?). I'd grabbed the button and shoved it between legs at exactly the same moment as the (rather attractive female) liftie grasped my walkie talkie and the strap it was attached to in an effort have a chat to whomever, presumably, was on the other end.
Well by the time my feet were yanked halfway up the slope and my face was buried in her crotch, I didn't know whether to be ecstatic or eviscerated
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FAQ
and they can be quite fun 
