143508 - Fragmentation theory reveals processes controlling iceberg size.pdf (709.19 kB)
Fragmentation theory reveals processes controlling iceberg size distributions
journal contribution
posted on 2023-05-20, 22:04 authored by Astrom, J, Susan CookSusan Cook, Enderlin, EM, Sutherland, DA, Mazur, A, Glasser, NIceberg 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.
History
Publication title
Journal of GlaciologyVolume
67Issue
264Pagination
603-612ISSN
0022-1430Department/School
Institute for Marine and Antarctic StudiesPublisher
Int Glaciol SocPlace of publication
Lensfield Rd, Cambridge, England, Cb2 1ErRights statement
Copyright 2021 the authors. Licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) https://creativecommons.org/licenses/by-nc-sa/4.0/Repository Status
- Open