Time-Dependent Surface Elevation of an ice Slope

Abstract By introducing a coordinate stretching, the governing field equations of the creep flow of a non-Newtonian viscous medium down a uniform slope are solved to determine the differential equation describing the propagation of long surface waves caused by initial disturbances and/or time-depend...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Hutter, Kolumban
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1980
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000010479
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000010479
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Summary:Abstract By introducing a coordinate stretching, the governing field equations of the creep flow of a non-Newtonian viscous medium down a uniform slope are solved to determine the differential equation describing the propagation of long surface waves caused by initial disturbances and/or time-dependent accumulation-rate The differential equation for the surface wave depends on the flow law of the non-Newtonian fluid, the boundary condition at the ice-bedrock interface, the bedrock topography and the thickness–wavelength ratio. For moderately long waves and small elevation above the mean thickness the results agree in their essentials with those of the kinematic wave theory and the forward wave equation with a diffusion term is derived, but when improving this by allowing higher elevations the Burger's equation and even more complex equations are obtained. To derive these results Glen’s flow law must be generalized to avoid infinitely fast changes in stress deviators close to zero Strain-rates, The range of applicability of the various equations is discussed.