Avalanche Rescue - Safety in Avalanche Terrain

Safety in Avalanche Terrain

• Terrain management - Terrain management involves reducing the exposure of an individual to the risks of travelling in avalanche terrain by carefully selecting what areas of slopes to travel on. Features to be cognizant of include not undercutting slopes (removing the physical support of the snow pack), not travelling over convex rolls (areas where the snow pack is under tension), staying away from weaknesses like exposed rock, and avoiding areas of slopes that expose one to terrain traps (gulleys that can be filled in, cliffs over which one can be swept, or heavy timber into which one can be carried).

• Group management - Group management is the practice of reducing the risk of having a member of a group, or a whole group involved in an avalanche. Minimize the number of people on the slope, and maintain separation. Ideally one person should pass over the slope into an area protected from the avalanche hazard before the next one leaves protective cover. Route selection should also consider what dangers lie above and below the route, and the consequences of an unexpected avalanche (i.e., unlikely to occur, but deadly if it does). Stop or camp only in safe locations. Wear warm gear to delay hypothermia if buried. Plan escape routes. In determining the size of the group balance the hazard of not having enough people to effectively carry out a rescue with the risk of having too many members of the group to safely manage the risks. It is generally recommended not to travel alone, because there will be no-one to witness your burial and start the rescue. Additionally, avalanche risk increases with use; that is, the more a slope is disturbed by skiers, the more likely it is that an avalanche will occur. Most important of all practise good communication within a group including clearly communicating the decisions about safe locations, escape routes, and slope choices, and having a clear understanding of every members skills in snow travel, avalanche rescue, and route finding.

• Risk Factor Awareness - Risk factor awareness in avalanche safety requires gathering and accounting for a wide range of information such as the meteorological history of the area, the current weather and snow conditions, and equally important the social and physical indicators of the group.

• Leadership - Leadership in avalanche terrain requires well defined decision making protocols that use the observed risk factors. These decision making frameworks are taught in a variety of courses provided by national avalanche resource centres in Europe and North America. Fundamental to leadership in avalanche terrain is honestly assessing and estimating the information that was ignored or overlooked. Recent research has shown that there are strong psychological and group dynamic determinants that lead to avalanche involvement.

Even small avalanches are a serious danger to life, even with properly trained and equipped companions who avoid the avalanche. Between 55 and 65 percent of victims buried in the open are killed, and only 80 percent of the victims remaining on the surface survive. (McClung, p.177).

Research carried out in Switzerland based on 422 buried skiers indicates how the chances of survival drop:

• Very rapidly from 92 percent within 15 minutes to only 30 percent after 35 minutes (victims die of suffocation)
• Near zero after two hours (victims die of injuries or hypothermia)

(Historically, the chances of survival were estimated at 85% within 15 minutes, 50% within 30 minutes, 20% within one hour).

Consequently it is vital that everyone surviving an avalanche is used in an immediate search and rescue operation, rather than waiting for help to arrive. Additional help can be called once it can be determined if anyone is seriously injured or still remains unaccountable after the immediate search (i.e., after at least 30 minutes of searching). Even in a well equipped country such as France, it typically takes 45 minutes for a helicopter rescue team to arrive, by which time most of the victims are likely to have died.

In some cases avalanche victims are not located until spring thaw melts the snow, or even years later when objects emerge from a glacier.