Snowfields and glaciers are prime targets for rockfall from bordering walls and ridges—espe cially on volcanic peaks, where the rock is often rotten and unstable. Climbers can reduce rockfall danger by wearing hard hats in hazardous areas and by timing climbs for less dangerous periods.
Early-season outings usually face less rockfall than summer climbs because snow still helps cement loose rock in place. Whatever the season, the general rule for glacier climbs is "early on and early off." Nighttime cold often freezes rock in place and prevents most rockfall, but direct sun melts the bonds. The greatest hazard comes in the morning when sun melts the ice, and in evening when meltwater expands as it refreezes, breaking rocks loose.
In the Northern Hemisphere, southern and east-em slopes get the sun first, and therefore should be climbed very early. The shadier northern exposures usually offer less rockfall danger.
Continue reading here: Routefinding Aids
Was this article helpful?