SponTaneous REArrangment of ice Motion (STREAM)

Antarctic and Greenland ice sheets lose most of their mass by a few corridors of rapidly flowing ice.

These ice conveyor belts constitute fast drainage routes whose flow velocities are undoubtedly sensitive to climate perturbations directly impacting sea-level.

Observations suggest the ice is rather sliding than flowing, the key being where sliding is accommodated. Commonly, sliding occurs at the ice-bedrock interface, but recent studies favour englacial sliding to explain data from Western Margin of Greenland.

Our aim is to demonstrate that the mechanisms controlling the spontaneous formation of englacial sliding explains the transition from slow flowing to fast sliding ice over Greenland. We employ the FastIce.jl thermo-mechanical ice flow model to predict thermally activated creep instability leading to the spontaneous rearrangement of ice motion in three dimensions.

Accurately resolving these nonlinear interactions on regional to ice sheet scales requires high spatial and temporal resolution which can only be achieved using a supercomputer. FastIce.jl is a massively parallel open-source ice flow solver whose latest version is written using the Julia language to feature a backend agnostic xPU implementation.

Julia enables scalable performance, portability and development productivity permitting a robust and cost-effective workflow from fast prototyping to deployment on Europe’s fastest supercomputer.