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Show GLOSSARY OF SNOW TERMS ACCUMULATION ZONE - In an avalanche path, the main c o l l e c t i o n area for snow. ASPECT - ( or exposure) - The p o s i t i o n or t e r r a i n facing a p a r t i c u l a r direct. North aspect faces north. AVALANCHE of snow - Rapid downhill snow movement-- sluffs, slides, f a l l i ng snow from t r e e s , etc. AVALANCHE HAZARD - A threat to l i f e and property from cascading snow. AVALANCHE SIZES - 1. Sluffs 2. Small 3. Medium 4. Large 5. Major CLIMAX AVALANCHE - A large or major slide which is a result of cumulative factors working over a longer interval of time than those associated with single storms. CORNICE - The overhanging lip of snow that develops from wind drifted snow on the lee of a ridge. DEBRIS - Snow, trees, rocks, etc., brought down by an avalanche and deposited at the terminus. DEPOSITION ZONE - That area in the avalanche path where the debris comes to rest. DEPTH HOAR - ( Also known as Cup Crystals and Sugar Snow) - New centers of crystallization caused by vertical diffusion of water vapor. ( Constructive metamorphism.) These crystals are of a different character than the original snow, and often are cup shaped and layered. Cohesion is very poor between the crystals. A steep temperature gradient within the snow cover usually will induce such formations. EXPOSURE - See Aspect FALL LINE - A line perpendicular to the contour, which has the greatest pull of gravity. The line a round ball would roll down if the slope was free from obstructions. FRACTURE LINE - The well- defined line across the top of the avalanche path where the slab breaks away from the stable snow. The face of the fracture is perpendicular to the slope. H. E. - High Explosives. LEE side of a slope - The side sheltered or protected from the wind. An eastern aspect would be the lee side for a western wind. ( See also Windward) PPT. - Abbreviation for precipitation. PROBE LINE - A line of rescuers, formed along the contour and facing uphill organized to probe the snow with poles to locate an avalanche victim. PROBE POLE - A lightweight metal pole, ( about 12 feet in length and 1" to 1" in diameter), used to penetrate the snow in searching for an avalanche victim. SLAB - A layer of snow held together by internal cohesion. Wind often a predominate but not necessary factor. SNOW PLUME ( Banners) - Snow being carried by the wind away from a peak or ridge into the air. 137 |