International Snow Science Workshop Proceedings - Montana State University Library

Item: How Do You Stress the Snowpack?

• • Title: How Do You Stress the Snowpack?

    Proceedings: Proceedings, 2012 International Snow Science Workshop, Anchorage, Alaska

    Authors:

    • Scott Thumlert  [ Department of Civil Engineering, Univ ersity of Calgary, Alberta, Canada ]
    • Bruce Jamieson  [ Department of Civil Engineering, Univ ersity of Calgary, Alberta, Canada ]  [ Department of Geoscience, Univer sity of Calgary, Alberta, Canada ]
    • Thomas Exner  [ Department of Geoscience, Univer sity of Calgary, Alberta, Canada ]

    Date: 2012

    Abstract: In the majority of fatal avalanches, skiers and snowmobilers apply load to the snowpack which triggers the initial failure in a weak layer. Understanding how the stress from a dynamic surface load transmits through the snowpack can help people avoid situations where they can trigger slab avalanches. Capacitive sensors were used to measure this stress within the mountain snowpack. The three main variables affecting stress transmission through the snowpack investigated in this paper are the type of loading, depth and properties of the snowpack. A decrease in stress was observed with increasing depth. At specific depths, snowmobiles added more stress than skiers did, thus increasing the probability of initiating a fracture in a weak layer and releasing a slab avalanche. The increased penetration depth of snowmobiles into the snowpack compared to skiers is the primary reason for this increase in stress. Falling skiers added about 3 times more stress than typical skiing. Skiers added about 1.5 times more stress than snowboarders. A decrease in stress was observed with increasing depth. Supportive surface layers created a “bridging effect” that spread stress out laterally and decreased the depth to which it penetrated.

    Object ID: issw-2012-506-512.pdf

    Language of Article: English

    Presenter(s): unknown

    Keywords: dynamic stress, localized dynamic loading, snowmobile, snow stability, avalanche forecasting, snowpack stratigraphy

    Page Number(s): 506-512

    Subjects: avalanche fatalities snowmobile snowpack properties

  • Get Full Article

Back to Home page