A new implementation of a calving model, using the finite-element code Elmer, is presented and used to investigate the effects of surface water within crevasses on calving rate. For this work, we use a two-dimensional flowline model of Columbia Glacier, Alaska. Using the glacier's 1993 geometry as a starting point, we apply a crevasse-depth calving criterion, which predicts calving at the location where surface crevasses cross the waterline. Crevasse depth is calculated using the Nye formulation. We find that calving rate in such a regime is highly dependent on the depth of water in surface crevasses, with a change of just a few metres in water depth causing the glacier to change from advancing at a rate of 3.5 km a^–1 to retreating at a rate of 1.9 km a^–1. These results highlight the potential for atmospheric warming and surface meltwater to trigger glacier retreat, but also the difficulty of modelling calving rates, as crevasse water depth is difficult to determine either by measurement in situ or surface mass-balance modelling.

Item Type:	Refereed Article
Keywords:	glaciology, ice-ocean interaction
Research Division:	Earth Sciences
Research Group:	Physical Geography and Environmental Geoscience
Research Field:	Glaciology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Earth Sciences
Author:	Cook, S (Dr Sue Cook)
ID Code:	102753
Year Published:	2012
Web of Science® Times Cited:	22
Deposited By:	CRC-Antarctic Climate & Ecosystems
Deposited On:	2015-09-04
Last Modified:	2017-10-30
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