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Kinetic energy transfer through impact and its role in entrainment by wind of particles from frozen surfaces
Author(s) -
NEUMAN CHERYL MCKENNA
Publication year - 1989
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.1989.tb01538.x
Subject(s) - geology , abrasion (mechanical) , kinetic energy , aeolian processes , sediment , particle (ecology) , geomorphology , mineralogy , materials science , composite material , physics , oceanography , quantum mechanics
While extensive aeolian deposits are associated with glaciation, little is known of the mechanisms which produced them. Observation of glaciofluvial sediments in Pangnirtung Pass, N.W.T., indicates that peak deflation occurs in the fall and winter months so that the nature of sediment transport involving frozen surfaces greatly differs from warm environments. Laboratory experiments indicate that such surfaces are mobilized through abrasion, and are most susceptible at low volumetric water content (less than 20%) and low temperature (–20°C). Stable surfaces have volumetric water contents in excess of 30% and temperatures of –15°C. Surface stability also increases with decreasing particle size, density and, possibly, transport load. Collisions with frozen surfaces are relatively elastic with significantly greater kinetic energy transfer to ejected surface grains than observed for loose dry surfaces. Saltation transport in cold environments could therefore be sustained at lower windspeeds than for dry surfaces provided that some loose particles are available initially but do not accumulate at the surface.