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{{B}}Avalanche and Its Safety{{/B}} An avalanche is a sudden and rapid flow of snow, often mixed with air and water, down a mountainside. Avalanches are{{U}} (51) {{/U}}the biggest dangers in the mountains for both life and property. All avalanches are caused by an over-burden of material, typically snowpack, that is too massive and unstable for the slope{{U}} (52) {{/U}}supports it. Determining the critical load, the amount of over-burden which is{{U}} (53) {{/U}}to cause an avalanche,{{U}} (54) {{/U}}a complex task involving the evaluation of a number of factors. Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low{{U}} (55) {{/U}}of avalanche. Snow does not{{U}} (56) {{/U}}significantly on steep slopes; also, snow does not{{U}} (57) {{/U}}easily on flat slopes. Human-triggered avalanches have the greatest incidence when the snow's angle of rest is{{U}} (58) {{/U}}35 and 45 degrees; the critical angle, the angle at which the human incidence of avalanches is greatest, is 38 degrees. The rule of thumb is: A slope that is{{U}} (59) {{/U}}enough to hold snow but steep enough to ski has the potential to generate an avalanche, regardless of the angle. Additionally, avalanche risk increases with{{U}} (60) {{/U}}; that is, the more a slope is disturbed by skiers, the more likely it is that an avalanche will occur. Duc to the complexity of the subject, winter travelling in the backcountry is never 100% safe. Good avalanche safety is a continuous{{U}} (61) {{/U}}, including route selection and examination of the snowpack, weather{{U}} (62) {{/U}}, and human factors. Several well-known good habits can also{{U}} (63) {{/U}}the risk. If local authorities issue avalanche risk reports, they should be considered and all warnings should be paid{{U}} (64) {{/U}}to. Never follow in the tracks of others without your own evaluations; snow conditions are almost certain to have changed since they were made. Observe the terrain and note obvious avalanche paths where plants are{{U}} (65) {{/U}}or damaged. Avoid traveling below others who might trigger an avalanche. |