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Iceberg calving strongly controls glacier mass loss, but the fracture processes leading to iceberg formation are poorly understood due to the stochastic nature of calving. The size distributions of icebergs produced during the calving process can yield information on the processes driving calving and also affect the timing, magnitude, and spatial distribution of ocean fresh water fluxes near glaciers and ice sheets. In this study, we apply fragmentation theory to describe key calving behaviours, based on observational and modelling data from Greenland and Antarctica. In both regions, iceberg calving is dominated by elastic-brittle fracture processes, where distributions contain both exponential and power law components describing large-scale uncorrelated fracture and correlated branching fracture, respectively. Other size distributions can also be observed. For Antarctic icebergs, distributions change from elastic-brittle type during ‘stable’ calving to one dominated by grinding or crushing during ice shelf disintegration events. In Greenland, we find that iceberg fragment size distributions evolve from an initial elastic-brittle type distribution near the calving front, into a steeper grinding/crushing-type power law along-fjord. These results provide an entirely new framework for understanding controls on iceberg calving and how calving may react to climate forcing.

Item Type:	Refereed Article
Keywords:	icebergs, ice shelf break-up, iceberg calving, ice-ocean interactions
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
UTAS Author:	Cook, S (Dr Sue Cook)
ID Code:	143508
Year Published:	2021
Web of Science® Times Cited:	4
Deposited By:	Australian Antarctic Program Partnership
Deposited On:	2021-03-22
Last Modified:	2021-10-07
Downloads:	14 View Download Statistics