Isochronal insights into ice flow evolution during the Last Glacial Period in Dronning Maud Land, Antarctica

Improving our understanding of past ice dynamics is essential for robust simulations of the future evolution of Antarctic Ice sheet and consequent sea-level rise projections. A major challenge in reconstructing paleo ice flow is the limited availability of temporal and spatial proxies to constrain ice evolution. Reconstructions on continental and regional scales often rely on broad ensembles constrained by present-day observations or sparse point data, such as past grounding line positions at specific locations. This sparse temporal and spatial coverage often proves inadequate for reconstructing the past conditions of the Antarctic Ice Sheet.

In this study, we employ Antarctica’s radar obtain stratigraphy, a repository of past changes in ice dynamics, climate and basal conditions, to constrain spatial and temporal changes in the evolution of the Dronning Maud Land, East Antarctica across the last 200kyrs. We use PISM to model ice flow, exploring the ice dynamics parameter space, and the influence of different geothermal fluxes, RACMO versions, grid sizes and basal parametrizations. To simulate the temporal climate signal, we use the climate index approach as well as accumulation information from EDML ice core. Finally, isochrones allow us to test and compare climate reconstructions and ice flow parameterizations, identify when mismatches occur during simulations, and distinguish between the effects of surface and basal processes.