Snow, Ice, Avalanches, and Glaciers - Mountain Geography: Physical and Human Dimensions - page 184

FIGURE 4.28 Approaching an avalanche shed protecting a highway in the Italian Alps below Simplon
Pass. Snow is allowed to cover the structures and avalanches slide harmlessly over the top. Struc-
tures like this are very common throughout the Alps. (Photo by L. R. Dexter.)
FIGURE 4.29 Avalanche diversion mounds like these near Chamonix, France, are often placed in run-
out zones to dissipate the energy of a flowing avalanche. (Photo by K. Birkeland.)
Another method of snow stabilization is simply to pack the snow down, often referred
to as boot packing. This is used at some ski resorts, where skiers and tracked vehicles
are constantly packing the newly fallen snow (Sahn 2010). Packing the snow increases
its strength and may help to inhibit weak-layer formation. In addition, the increased
variability introduced by boot packing increases the spatial variability of the snowcover,
and modeling suggests this may also be helpful for slope stabilization (Kronholm and
Birkeland 2005). Research is constantly being done to discover new ways of mitigating
avalanches. However, the current mitigation and forecasting techniques have clearly
reduced the potential hazards in many areas, allowing their winter use. Mitigating ava-
lanches is expensive, and it will never be possible to protect all people from all ava-
lanches, especially the dispersed backcountry skiers, snowboarders, and snowmobilers
who play in steep, avalanche-prone terrain. In the long run, the best defense is care-
fully locating facilities to avoid avalanche terrain, and carefully timing activities to avoid
times of high avalanche danger.
Glaciers