TY - JOUR
T1 - Fragmentation Theory Reveals Processes Controlling Iceberg Size Distributions
AU - Åström, Jan
AU - Cook, Sue
AU - Enderlin, Ellyn M.
AU - Sutherland, David A.
AU - Mazur, Aleksandra
AU - Glasser, Neil
N1 - Publisher Copyright:
Copyright © The Author(s), 2021. Published by Cambridge University Press.
PY - 2021/8
Y1 - 2021/8
N2 - 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.
AB - 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.
KW - ice shelf break-up
KW - ice/ocean interactions
KW - iceberg calving
KW - icebergs
UR - http://www.scopus.com/inward/record.url?scp=85113194848&partnerID=8YFLogxK
UR - https://scholarworks.boisestate.edu/geo_facpubs/603
U2 - 10.1017/jog.2021.14
DO - 10.1017/jog.2021.14
M3 - Article
SN - 0022-1430
VL - 67
SP - 603
EP - 612
JO - Journal of Glaciology
JF - Journal of Glaciology
IS - 264
ER -