Effect of presence of basal facies on glacier behaviour

It is clear that the presence of a rheologically different layer at the base of glacier or ice sheet will have a major effect not only on the dynamics of an ice mass, but also, as a result, on its morphology and extent (Boulton & Jones, 1979; Beget, 1986). However, there have been relatively few studies examining the effect of softer basal ice layers on glacier dynamics, although the importance of the issue is often indicated. In a recent study, Hubbard etal. (2004) explicitly examined the impact on glacier response behaviour of the presence of two softer layers in the basal zone in a case study at the Tsanfleuron Glacier. They found significant differences between predictions for response using multilayered models. In particular, they found that a multilayered glacier with rheologies constrained by field observations of basal ice was more sensitive in a retreat scenario than a single layered glacier with a rheology constrained by observations of overlying glacier ice.

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