Rock climbing involves knowledge of rope handling. Climbers use a rope to belay, or secure, one another; one climbs while another holds the rope to protect against any fall or slip. A technique called rappelling is used in descending very steep terrain. The rope is attached in such a way that it can be pulled down after the last climber has used it; descending along the rope, the climbers use the friction thus generated (often absorbed by a mechanical device attached to their bodies) to control their rate of descent. Techniques now used for the steepest rock climbs include the use of chocks, devices that are wedged into crevices in the rock. The rope is attached to these by means of snap rings called carabiners. Vertical and overhanging rock faces may also require use of short ladder like loops of nylon webbing, attached to the rock by the lead climbers. Following climbers can then use two mechanical ascenders that alternately grip and release the rope as the climber goes up, while standing in attached stirrups.
Rock climbing originated as a means of practicing techniques for ascending high mountains; it has evolved into a highly developed sport in itself. Major centers of activity include Yosemite Valley, California, the limestone cliffs of the Shawangunks in New York State; the hillsides, quarries, and sea cliffs of the British Isles; and the Dolomites in northern Italy.
ICE CLIMBING
Routes moderately covered with snow can be safely climbed using an ice axe to cut steps, probe crevasses, give balance, and belay the rope. Steeper snow- and ice-covered routes require crampons, devices with 12 or more sharp steel points that are strapped onto each boot. Glacier routes require the use of slings and additional equipment so that a climber who falls into a crevasse may quickly climb or be hauled out.
ROCK CLIMBING