Snow, Ice, Avalanches, and Glaciers - Mountain Geography: Physical and Human Dimensions - page 167

FIGURE 4.14 Ice formations in lakes. (Image courtesy of L. R. Dexter and K. Birkeland.)
FIGURE 4.15 Ice formations in rivers. (Image courtesy of L. R. Dexter and K. Birkeland.)
Snow Avalanches
Snow avalanches are the sudden release and movement of vast amounts of snow down
a mountainside under the influence of gravity (Fig. 4.16). Avalanches are one of the
great destructive forces in nature, every bit the equal of hurricanes, tornadoes, or earth-
quakes, and they can be an awe-inspiring phenomenon to witness. Thousands of persons
have perished in avalanches over the centuries. If mountains were more heavily pop-
ulated, the toll would be even higher. Untold numbers of avalanches occur every year,
but only a few are observed or recorded. As the number of people living and recreating
in the mountains increases, the potential for avalanche damage increases markedly as
well.
Avalanches have been investigated ever since the time of Strabo, who commented on
their occurrence in Geographica IV in A.D. 16:
It is difficult to protect oneself against ice sheets sliding down from above
which are capable of hurling entire caravans into the gaping abysses. Many such
sheets lie one on top of another because one snow layer after another turns to