Ronja Reese (Northumbria University Newcastle) – Exploring the stability of the Antarctic Ice Sheet

The Antarctic Ice Sheet can undergo non-linear dynamics due to the Marine Ice Sheet Instability (MISI). Observations of ocean-driven grounding line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet due to MISI. This would raise global sea levels by more than three metres, impacting coastal regions and communities worldwide. A collapse would be caused by irreversible retreat of the ice sheet’s grounding lines – the positions where the formerly grounded ice starts to float. Here we analyse whether Antarctic grounding lines are undergoing a Marine Ice Sheet Instability in their current position. Furthermore, we investigate the committed evolution of Antarctic grounding lines under present-day ocean and atmospheric conditions and put this into past context, in order to understand the stability of the (West) Antarctic Ice Sheet.