Flow dynamics of tidewater glaciers: a numerical modelling approach

Vieli, A.; Funk, M.; Blatter, H.

Abstract

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.

Citation

Vieli, A., Funk, M., & Blatter, H. (2001). Flow dynamics of tidewater glaciers: a numerical modelling approach. Journal of Glaciology, 47(159), 595-606. https://doi.org/10.3189/172756501781831747

• Journal Article Type: Article
• Publication Date: 2001-12
• Deposit Date: Nov 14, 2006
• Publicly Available Date: Apr 6, 2010
• Journal: Journal of Glaciology
• Print ISSN: 0022-1430
• Electronic ISSN: 1727-5652
• Publisher: International Glaciological Society
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Issue: 159
• Pages: 595-606
• DOI: https://doi.org/10.3189/172756501781831747
• Keywords: Southern Patagonia, Subglacial Water, Columbia Glacier, Hydrologic Basis, Rapid Motion, San-Rafael, Alaska, Switzerland, Stability, Pressure.
• Public URL: https://durham-repository.worktribe.com/output/1598680