| Summary: | The hypothesis that the West Antarctic ice sheet is inherently unstable because its bed is below sea level (the marine ice sheet hypothesis) is tested using a one-dimensional ice-flow model. Based on continuity and a simplification of the flow law, the model follows a flow line from the ice divide, through an ice stream and into an ice shelf. Longitudinal stretching is taken to be constant with depth, and a vertically-averaged softness parameter is used. The boundary conditions are the current ice sheet, assumed to be steady, and specified longitudinal stress near the divide or calving front. Lateral flow convergence is specified and vertically-averaged velocities, longitudinal stretching stresses, driving stresses, and resistive drag (including basal drag) are calculated. Time-dependent inland ice profiles associated with a rise in sea level, are calculated by reducing the resistive drag near the grounding line. Different schemes for the redistribution of drag and resulting glacial responses are presented. Results show that local adjustments due to a reduction in resistive drag near the grounding line take on the order of 10^2 years. No embargo
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