Essential Skills for Glacier Ski and Splitboard Touring
Glacier ski touring skills are vital for skiers and splitboarders in being able to anticipate and manage the hazards of the glacier and avalanches. Late August to mid-October is the prime time on New Zealand’s high glaciers. Once the depth of winter has past, the days are getting longer and glaciers are filled in with seasonal snow allowing generally straightforward travel. Storms can provide a reset to winter snow conditions and provide fresh powder snow for days or sunny slopes can be worked for prime corn skiing.
Managing Glacier Hazards
When seasonal snow levels are up, crevasses are generally well bridged with supportive snow. Good route finding can generally avoid the worst areas of crevasses. There is however always the risk of falling into a hidden crevasse. Times, when this risk is increased, are when fresh snowfall masks the signs of underlying slots or following periods of cold, settled weather during which snowpack metamorphosis can reduce the strength of snow bridges.
Any fall results in potentially the most challenging and foreseen technical rescue situation that is likely to be encountered in the mountains.
It is standard practice for all the members of a glacier ski or splitboard touring team to be familiar with, have the equipment for and be practised in self and companion crevasse rescue.
Managing Avalanche Hazard
There is also the avalanche hazard to manage and this complex topic in its own right. On the glaciers, the snowpack will tend towards being more stable as the spring touring season progresses but any new snow, rain or wind will elevate the hazard. As well as recognising avalanche terrain and the conditions that elevate the hazard, shovel, transceiver and probe and familiarity with their use is also important.
Any crevasse fall could potentially result in injury and at the least prove time-consuming. An idea of where crevasses are most likely to be encountered can be determined by looking at the terrain. Good route finding on snow covered glaciers will reduce exposure to falling in a crevasse.
Complex crevasse systems are likely to be found by analysing the terrain and identifying areas of the glaciers that are steeper, in tension (over convexities) or where there is more friction (towards the sides).
It is not usual practice for ski or splitboard tourers to rope up on glaciers providing conditions are good. Route finding, visibility of any open crevasses and the increased surface area provided by skis provide some mitigation against the risk of falling in a crevasse.
However, in unfamiliar and/or broken terrain, when visibility is limited by weather, approaching a visible crevasse or travelling through a complex area of crevasses, known crevasses, roping up provides further security against unexpected crevasse falls.
Roping Up for Glacier Travel
For two people to move together with even 30 metres of rope between them is difficult to manage so the rope is typically shortened to between 8 to 12 metres with the excess rope divided and carried by each person. Having excess rope is important for companion rescue. This spacing is dictated by what is known about the size of the crevasses and the distance between them in the area that they are travelling. The aim is to avoid more than one person being exposed to the same crevasse at the same time and maximise the chance of holding a crevasse fall.
Shortening the rope
Ski tourers will typically carry 30m – 60m of rope. Not all of this length There are a number of methods for carrying the excess rope. All techniques start by finding the middle of the rope and measuring out 5-8 metres towards each end. At the chosen spacing a bight knot (such as an overhand knot on a bight or an alpine butterfly) is used to attach to the rope. More rope will be needed than the intended distances between members to account for tying brake knots.
Carrying the excess rope in a backpack is an option if it is not already too full and can be more comfortable than mountaineering coils where the weight is around the carrier’s neck. If transitioning from glacier travel to pitching is anticipated during the day, it is important for each person to tie into the ends of the rope. Start by feeding the end of the rope or from the tie-in to the harness into the top of the pack or a stuff sack until the bight knot at the chosen spacing is reached. A stuff sack is useful as the rope can be taken out to access other items from the pack. The bight knots can be clipped directly to the belay loop of the harness. In the event of a glacier fall, a bight knot is easier to escape from and therefore preferable to a clove hitch. To prevent potential Cross-loading a directional (eg Climbing Technology Concept HMS Triple Lock Carabiner®) or two opposed carabiners are recommended when clipping into a bight knot.
Holding a crevasse fall when there are only two people on a rope is difficult, especially when the person falling into the crevasse is significantly heavier than the person holding the fall.
One way to increase the chances of holding such a fall is to tie brake knots (overhand on a bight or an alpine butterfly) in the rope about 2-3 metres from each person. The knot will tend to drag through the snow or catch on the crevasse lip as the person falls into the crevasse and can significantly reduce the amount of effort needed for the person on the surface to hold the fall.
Moving roped up
When crossing obvious crevasses it is important to try to keep the rope between members of the team tight and as close to 90o to the crevasses as possible. This may require different team members to take different lines.
If travelling parallel to the crevasses, it can be advantageous to travel in echelon formation with the rope perpendicular to the direction of travel. This is to avoid more than one person standing over the same crevasse at the same time and avoids pendulum falls that can be difficult to arrest.
The rope between team members should not be too slack. A loose rope compromises the safety of the party as it increases the shock loading when a fall occurs and can dramatically reduce the chances of successfully holding a crevasse fall. Excessively loose rope can also pose a trip hazard. Too tight however can make it difficult for all members to maintain an efficient pace. Good tension is achieved when the rope is dancing along the snow surface at the bottom of its arc.
With more than two people on a rope, the chances of successfully holding a fall of any member of the party is increased. When roping up with three or more people, those not on the ends can clip their belay loop into a bight knot in the middle of the rope using a triple-lock carabiner or two opposed carabiners. Alternatively, they could tie directly in with a re-threaded overhand knot. The distance between each person should still be between 8 to 10 metres.
Glacier Ski Touring Equipment Selection
It is usual to have two or more ropes in the party for this purpose and for use in crevasse rescue. Having a rope setup to deploy quickly will make the decision to rope up easy if required. The system is not important provided there is separation between rope party members. It does not need to be a fully rated single rope (providing there are no ski mountaineering objectives involved) so a half rope or, whilst understanding it’s limitations, an accessory chord.
Coming up next: Crevasse Rescue skills for Glacier Ski Touring
For more information and to sign up for expert instruction from certified mountain and ski guides, check out Wānaka Mountain Guides’: short local Glacier Travel and Crevasse Rescue Courses or multi-day, high alpine-based Glacier Ski and Splitboard Touring Courses or Ski Mountaineering Courses.