Snow Displacement & Speed Control in Sastrugi
As promised from the Snoworks Facebook page it’s technical week at Snoworks. This is where we answer all your technical questions. First up – How to ski sastrugi.
(From Wilipedia) Sastrugi are sharp irregular grooves or ridges formed on a snow surface by wind erosion and deposition and found in polar snow regions (i.e. Scotland). Larger features are especially troublesome to skiers. Skiing on the irregular surface of sastrugi can be very difficult. The surface is hard and unforgiving with constant minor topographic changes between ridge and trough.
HOW TO SKI IT?
It’s all to do with speed control.
Ask almost anyone how they control speed or slow down and 99.9% of responses would be ‘turn’. Of course if you turn to slow down on sastrugi you’ll go arse over xxx.
The problem is very few skiers know how to accurately control speed and if it’s turning that you think controls your speed then every time you are not turning you will be picking up speed. Now that’s worrying especially in sastrugi.
So, how do we control speed? The answer to this is to think about what happens when you do turn. The edges of your skis travel sideways across the snow. A kind of scraping action on the snow. What we know in the trade as ‘SKIDDING’. Now there’s a dirty work – SKIDDING. If I could have a pound for every skier we have taught who believes they must not skid I’d be a rich man.
SKIDDING is when the edges of your skis travel sideways across the snow and is vital for controlling speed. With such a bold statement I better clarify what SKIDDING is and how we can get very skillful at it and how you can use it to ski sastrugi. First of all I am going to change the name. I’ve said that SKIDDING is where the edges of the skis travel sideways across the snow. So lets call it SNOW DISPLACEMENT instead, which make far more sense. So as your edges move sideways across the snow you displace some snow which controls your speed.
The problem is if you let your skis travel sideways in sastrugi you’ll catch an edge and go arse over xxx again.
What we therefore need to do is not ‘let’ our skis travel sideways but actively ‘push’ the edges sideways. This way you can be assured of not catching edges and still displacing enough snow to control your speed.
Now sastrugi can be pretty difficult to move. But as we say at Snoworks if you can move it you can ski it. You have to move the top surface of the sastrugi with your ski edges and displace enough snow to control your speed.
It’s you versus the sastrugi and someone has to win. Wind formed snow surface or the might and power of your quadriceps and glutes. The three muscles of the glutes plus the four muscles that make up the quads. That’s seven large muscles versus wind formed snow!
Either you move it or it moves you!
Now you need confidence and belief. Get your edges and move the top surface of the sastrugi like using a knife to scrape the burnt porridge off the bottom of your saucepan after its sat overnight (believe me, my wife can burn porridge like nobody else!).
Displace enough of the sastrugi with your edges and you’ll have perfect speed control. Belief and determination and the knowledge of snow displacement is all you need. (Strong quads and glutes also helps).
Phil
Phil Smith is director of Snoworks Ski Courses and having done much of his skiing in Scotland is well used to skiing on sastrugi. You can learn the skills of sastrugo skiing on a Snoworks All-Terrain Ski Course.
photo: Climbing up Osorno Volcano in Chile. Snoworks Chile Adventure.
