Deformation in the vicinity of ice divides

CF Raymond - Journal of Glaciology, 1983 - cambridge.org
CF Raymond
Journal of Glaciology, 1983cambridge.org
Numerical calculations by finite elements show that the variation of horizontal velocity with
depth in the vicinity of a symmetric, isothermal, non-slipping ice ridge deforming on a flat bed
is approximately consistent with prediction from laminar flow theory except in a zone within
about four ice thicknesses of the divide. Within this near-divide zone horizontal shear strain-
rate is less concentrated near the bottom and downward velocity is less rapid in comparison
to the flanks. The profiles over depth of horizontal and vertical velocity approach being linear …
Numerical calculations by finite elements show that the variation of horizontal velocity with depth in the vicinity of a symmetric, isothermal, non-slipping ice ridge deforming on a flat bed is approximately consistent with prediction from laminar flow theory except in a zone within about four ice thicknesses of the divide. Within this near-divide zone horizontal shear strain-rate is less concentrated near the bottom and downward velocity is less rapid in comparison to the flanks. The profiles over depth of horizontal and vertical velocity approach being linear and parabolic respectively. Calculations for various surface elevation profiles show these velocity profile shapes are insensitive to the ice-sheet geometry.
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