OCR Text |
Show resulting in a large avalanche into upper corkscrew and across the ridge into the Meadow. F i r i n g on targets at the head of Peruvian Gulch released a series of major avalanches throughout the e n t i r e Upper Peruvian Gulch. These in turn triggered the major s l i d e paths in the next two canyons to the west. COMMENTS A highly unstable snow condition like this represents the most dangerous type of avalanche situation. Even the most minor disturbance or displacement of a single small slide can set an entire mountain- side into motion, or inundate the head of an entire canyon, bringing down large and dangerous avalanches at points far distant from the initial disturbance. Fracturing and avalanche release on this occasion literally propogated for miles throughout the Alta area from the triggering effect of single artillery shells. The major avalanche cycle of 24 January was the largest observed in Little Cottonwood Canyon in several years. Disastrous consequences might well have resulted if the natural avalanche cycle had been left uncontrolled and widespread avalanche release had occurred with skiers on the lifts, slopes and highways. The decision to shoot in such circumstances, at the risk of property damage, is not an easy one. In a similar situation at Alta in 1965, the decision was not to shoot. Canyon residents retired to the basements for safety, large avalanches fell by natural release, and extensive damage occurred anyway. The only serious crisis in 1964 arose from the ill- founded rumor at Peruvian Lodge that the shooting was over, just when the avalanche hazard was most dangerous. After this incident, ski patrolmen were stationed at the door of each lodge to keep people inside, where they should have been at the beginning of the control program. In dealing with the unpredictable mixture of avalanche and skier, the Snow Ranger must never take anything for granted. No. 64- 11 POCATELLO. IDAHO 7 March 1964 WEATHER FACTORS Weather conditions unknown. ACCIDENT SUMMARY Two ten- year- old boys were playing with several friends in a snow covered gully in the " bench" area of West Pocatello. The boys were sliding down the side of the gully when they suddenly sank out of sight and a large 115 |