Penitentes

As penitents, or penitents Zackenfirn (English: Snow Penitents or Ice Penitents, Spanish: Nieve de los Penitentes ) are up to 6 m high snow and ice pyramids in high mountains of the tropics and subtropics (eg the Andes ) refers. On the Khumbu Glacier on Mount Everest high Ice Penitents were observed up to 30 meters.

Is caused by uneven penitents ablation ( ablation) in strong direct sunlight and low humidity in the randtropisch and subtropical zone. The tips of the snow pyramids show the direction of the midday sun. For climbers, this type of glacier and Firnfeldoberfläche usually an insurmountable difficulty dar.

The formation process would start by small depressions in the snow. At the bottom strikes than anywhere else more reflected light, causing them to deepen faster than their higher margins. The effect is likely to be reinforced in climates where the dew point is below freezing and the same prevails strong sunlight. There snow on the tips of the peaks can not melt the snow, but rather to be removed at best by sublimation. In the sheltered depressions however, it is more humid and thus higher the dew point, so that the ice can melt. As for Sublimation more solar energy than is necessary for mere melting, the deepening process goes ahead there faster than at the tips.

The term was coined by the penitents painter and mountaineer Rudolf Reschreiter, who described an expedition to Chimborazo and Cotopaxi the first time this phenomenon and painted. The inclined Pip reminded him of penitents with bowed head and bent back.