Thursday 19 February 2015

Below 30 degrees

Skiing powder on low angle slopes
Below 30 sounds parky but in fact I'm thinking slope angle. This season there's already been an extraordinarily high number of skiers killed by avalanches. Many could have been avoided with better awareness and education in what causes slopes to slide.

One rule that's easy to follow is to keep to gentle terrain. Slopes less than 30 degrees in angle are generally unlikely to slide. But remember, look at what's above you too, even if your on the gentle stuff vibrations can ripple through the pack and break those weak layers in the steeper terrain above causing it to slide.

So how to tell the slope angle:

Topographical maps with winter routes,  have terrain over 30 degrees shaded in pink. For Switzerland there's an excellent range of 1: 50 000 produced and available from www.swisstopo.ch

Pink shaded steep slopes on the swisstopo maps

You can go online to use the excellent interactive mapping site with more detailed shading
www.map.geo.admin.ch

You can also attach an inclinometer to your ski pole. Then you simply lay your pole on the ground and see what angle it says. There are also poles with it already built in - K2 have an adjustable carbon pole - (LockJaw £95) unfortunately it measures from 30 - 50 degrees so if you can see the bubble your on the wrong slope...

Built in inclinometer on the K2 LockJaw ski pole