Item: Empirical analysis of snow deformation below penetrometer tips
Title: Empirical analysis of snow deformation below penetrometer tips
Proceedings: Proceedings of the 2006 International Snow Science Workshop, Telluride, Colorado
Authors: James Floyer and Bruce Jamieson, Department of Geology and Geophysics, University of Calgary, Department of Civil Engineering, University of Calgary
Abstract: Recent field observations suggest that when an object, such as a digital snow penetrometer, is pushed through snow, a zone of densified snow develops in front of it. It is this zone of densified snow, rather than the actual tip of the object itself, that impacts on newly encountered snow as the object is pushed deeper into the snowpack. The concept of a compacted zone is introduced to describe this zone of snow. This is a sub-region of the broader deformation zone that encompasses all snow deformation below the tip of the penetrating object. The shape of both the deformation zone and compacted zone is influenced by the shape of the object’s tip but also by the density, temperature, moisture content, grain size and grain shape of the snow through which the object is being pushed. The compacted zone effect is described and the impact on snow deformation of different snow densities and different tip shapes is preliminarily assessed. The use of particle image velocimetry in conjunction with a moving body coordinate system is presented as a useful tool for analysing deformation patterns for moving objects through uniform snow. The importance of this effect for penetrometer tip design and assessment of vertical resolution is discussed. Data is taken from a series of video and rapid-fire still camera shots of different shaped penetrometer tips being pushed through a clear, stiff plastic box filled with snow. Snow confinement along the side of the snow box is identified as a limitation of this technique.
Keywords: snow deformation, penetrometer, compacted zone, snowpack stratigraphy
Digital Abstract Not Available