Item: The relationship between measured snow hardness and shear strength
Title: The relationship between measured snow hardness and shear strength
Proceedings: 2010 International Snow Science Workshop
Authors: Peter Höller*, Reinhard Fromm Federal Research Centre for Forests, Department Natural Hazards; Innsbruck, Austria
Abstract: Snow hardness is an important parameter in avalanche forecasting; however, hardness has not that relevance as the shear strength of snow. On the other hand hardness measurements are easier to operate and they are more suitable for practitioners. The snow hardness correlates approximately with the shear strength of snow; low hardness may be an indicator for weak layers (e.g. depth hoar). This study aims to quantify the shear strength with data of hardness measurements. For that purpose both, traditional hand hardness observations and objective hardness measurements were carried out. The snow hardness was measured in horizontal direction with a digital push-pull gauge. The shear strength was measured with a shear frame (size 0.05m2). All measurements were done at intervals of 10cm vertically. The analysis of the scattering data allows an interpretation of the relationship between the snow hardness and the shear strength. Especially lower hardness levels (up to 100kPa) show a clear correlation.
Keywords: snow hardness, shear strength, push-pull gauge