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Article Dans Une Revue Journal de Physique Colloques Année : 1987

FIRN DENSIFICATION BY GRAIN-BOUNDARY SLIDING : A FIRST MODEL

R. Alley
  • Fonction : Auteur

Résumé

Densification in highly porous, isothermal firn occurs primarily by Newtonian sliding on grain boundaries, but the coordination number increases with density and restricts further sliding. At a relative density of about 0.6 the coordination number approaches 6 and sliding ceases to be a primary mechanism of densification ; the resulting decrease in densification rate causes the critical point in depth-density profiles. A simple model for densification by boundary sliding yields a good fit to observed profiles. The viscosities so obtained give an activation energy equal to that for grain-boundary diffusion.

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jpa-00226281 , version 1 (04-02-2008)

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R. Alley. FIRN DENSIFICATION BY GRAIN-BOUNDARY SLIDING : A FIRST MODEL. Journal de Physique Colloques, 1987, 48 (C1), pp.C1-249-C1-256. ⟨10.1051/jphyscol:1987135⟩. ⟨jpa-00226281⟩

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