Snow Formation and Avalanches : Page 202

For the purpose of this chapter, it will be presumed that the skier who travels in terrain that spawns such avalanches will be fully prepared, by study and experience acquired elsewhere, for the problems that will confront him. But a milder hazard from falling ice is frequently encountered in any rugged ski terrain. Water from melting snow will freeze on cliffs during the night, or whenever the temperature is low enough, and will break loose with the first thaw. The breaking loose of large accumulations of ice may cause a snow avalanche on the slopes below. It is usually easy to see where such bombarded areas exist, and to plan a route that avoids them, or to time the trip so the party passes beneath the cliffs when the ice is frozen.