Vieli, A. and Funk, M. and Blatter, H. (2001) 'Flow dynamics of tidewater glaciers : a numerical modelling approach.', Journal of glaciology., 47 (159). pp. 595-606.
The dynamics of grounded tidewater glaciers is investigated with a time-dependent numerical flow model, which solves the full equations for the stress and velocity fields and includes a water-pressure-dependent sliding law. The calving criterion implemented in the model shifts the calving front at each time-step to the position where the frontal ice thickness exceeds flotation height by a prescribed value. With this model, the linear relation between calving rate and water depth proposed on empirical grounds is qualitatively reproduced for the situation of a slowly retreating or advancing terminus, but not for situations of rapid changes. Length changes of tidewater glaciers, i.e.especially rapid changes, are dominantly controlled by the bed topography and are to a minor degree a direct reaction to a mass-balance change. Thus, accurate information on the near-terminus bed topography is required for reliable prediction of the terminus changes due to climate changes. The results also confirm the suggested cycles of slow advance and rapid retreat through a basal depression. Rapid changes in terminus positions preferably occur in places where the bed slopes upwards in the ice-flow direction.
|Keywords:||Southern Patagonia, Subglacial Water, Columbia Glacier, Hydrologic Basis, Rapid Motion, San-Rafael, Alaska, Switzerland, Stability, Pressure.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.3189/172756501781831747|
|Publisher statement:||© 2001 International Glaciological Society|
|Record Created:||14 Nov 2006|
|Last Modified:||03 Aug 2011 16:26|
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