Small-scale modeling of ice flow perturbations induced by sudden ice shelf breakup

• We simulate flow of a valley glacier draining an ice sheet grounded above sea level into an ice shelf
• Results give insights into the flow perturbations induced by ice shelf collapse
• A significant increase in glacier velocity follows ice shelf breakup
• This effect does not significantly propagate upstream and rapidly decays with time
• Basal lubrication and ice thickness do not significantly influence the process

The sudden breakup of ice shelves is expected to result in significant acceleration of inland glaciers, a process related to the removal of the buttressing effect exerted by the ice shelf on the tributary glaciers. In this paper, this process is analyzed by means of scaled analogue experiments reproducing the flow of a valley glacier draining an ice sheet grounded above sea level into an ice shelf, and analyzing the dynamic perturbations resulting from ice shelf disintegration and removal of buttressing effect. Models show a significant increase in glacier velocity close to its outlet following ice shelf breakup, a transient effect that does not significantly propagate upstream towards the ice sheet and rapidly decays with time. Basal lubrication and variations in ice thickness do not significantly influence the process that thus leaves the ice sheet almost unaffected by flow perturbations.