TY - GEN
T1 - FIRN DENSIFICATION BY GRAIN-BOUNDARY SLIDING
T2 - A FIRST MODEL.
AU - Alley, R. B.
PY - 1987/1/1
Y1 - 1987/1/1
N2 - 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.
AB - 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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U2 - 10.1051/jphyscol:1987135
DO - 10.1051/jphyscol:1987135
M3 - Conference contribution
AN - SCOPUS:0023309694
SN - 286883051X
SN - 9782868830517
T3 - Journal de Physique (Paris), Colloque
SP - 249
EP - 256
BT - Journal de Physique (Paris), Colloque
ER -