Item: Spatial variability of slab stability in avalanche start zones
Title: Spatial variability of slab stability in avalanche start zones
Proceedings: 2002 International Snow Science Workshop, Penticton, British Columbia
Authors: Kyle Stewart and Bruce Jamieson, Department of Geology and Geophysics, University of Calgary, Alberta, Canada, Department of Civil Engineering, University of Calgary, Alberta, Canada
Abstract: Spatial variability of slab stability in avalanche start zones has been observed by avalanche professionals but little research has been published that shows the amount or causes of this variability, or patterns of stability. A quantitative variation of the compression test was refined to test stability many times within a few hours. Each of these tests consists of an annular brass weight dropped from 5 to 55 cm in 5 cm increments, down a guide rod onto a 30 cm by 30 cm rigid plate until fracture occurred in the weak layer. Between December 2000 and April 2002, thirty-nine spatial arrays were conducted on slabs in the Columbia Mountains of British Columbia. Each array consisted of between 40 and 120 drop hammer tests, each conducted in a single day in an avalanche start zone. Many arrays show relatively consistent stability within the start zone. Clusters of low or high scores (stability) ranging in size upwards from 2 m were observed in some of the arrays.
Keywords: snow stability, stability tests, avalanches, spatial variability
Digital Abstract Not Available