Characterizing the microstructural and micromechanical properties of snow

A micropenetrometer has been developed that produces snow grain bond ruptur es at the microstructural level and provides a unique signal for different snow types. A micromechanical theory of penetration has been developed and used to recover microstructural and micromechanical parameters for differen t snow types from the penetration force-distance signal. These parameters a re the microstructural element dimension, the mean grain size, the critical microstructural deflection at rupture and the microstructural coefficient of elasticity. Additional derived mechanical properties include the compres sion strength and elastic modulus of microstructural elements and continuum scale volumes of snow. Analysis of the force-distance signal from a Monte Carlo simulation of micropenetration indicates that microstructural and mic romechanical parameters may be recovered with a measurement accuracy of bet ter than 5% when spatial and force resolutions are high and the penetromete r tip area is of similar size to the structure dimension. (C) 1999 Elsevier Science B.V. All rights reserved.