Book excerpt: Technical yet accessible, The Avalanche Handbook, 3rd Edition, covers the formation, character, effects, and control of avalanches; rescue techniques; and research on understanding and surviving avalanches. Illustrated with nearly 200 updated illustrations, photos and examples, the revised edition offers exhaustive information on contributing weather and climate factors, snowpack analysis, the newest transceiver search techniques, and preventative and protective measures, including avalanche zoning and control. It contains new information on the unique characteristics of alpine snow, snow slab instability, terrain variables, skier triggering of avalanches, and the nature of avalanche motion. Plus brand-new chapters on the elements of backcountry avalanche forecasting and the decision-making process.