Abstract
Rapid ice loss is facilitated by sliding over beds consisting of reworked sediments and erosional products, commonly referred to as till. The dynamic interplay between ice and till reshapes the bed, creating landforms preserved from past glaciations. Leveraging the imprint left by past glaciations as constraints for projecting future deglaciation is hindered by our incomplete understanding of evolving basal slip. Here, we develop a continuum model of water-saturated, cohesive till to quantify the interplay between meltwater percolation and till mobilization that governs changes in the depth of basal slip under fast-moving ice. Our model explains the puzzling variability of observed slip depths by relating localized till deformation to perturbations in pore-water pressure. It demonstrates that variable slip depth is an inherent property of the ice-meltwater-till system, which could help understand why some paleo-landforms like grounding-zone wedges appear to have formed quickly relative to current till-transport rates.
Highlights
Rapid ice loss is facilitated by sliding over beds consisting of reworked sediments and erosional products, commonly referred to as till
The Intergovernmental Panel on Climate Change ascribes the largest uncertainty in future sea level rise to the ice dynamics of our two ice sheets, Greenland and Antarctica[1]
While ice-ocean interactions have received considerable attention over recent years[3,4,5], our ability to predict the evolution of basal conditions underneath the ice sheets remains limited
Summary
Rapid ice loss is facilitated by sliding over beds consisting of reworked sediments and erosional products, commonly referred to as till. To test the hypothesis that meltwater input can alter the depth at which basal slip is concentrated, we impose daily sinusoidal variations in water pressure at the top of the model domain and simulate pore-pressure diffusion and the resultant shear dynamics over seven days (Fig. 2a and Supplementary Fig. 2).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
