Modelling the Evolution of West Antarctica Through the Last Glacial Maximum and Holocene Constrained by Radar Isochrones

Constraining paleo-modelling results of the West Antarctic Ice Sheet (WAIS) has primarily been restricted to using individual point-based measurements such as ice and sediment cores. However, these records only provide a one-dimensional picture of temperature/accumulation and ice-sheet/grounding-line extent respectively. Additionally, the extent to which these measurements are representative of the wider region in which they are situated is uncertain. This in turn impacts our ability to constrain paleo simulations of the ice sheet from physics-based models. Here, we make use of a spatially extensive age-depth model, compiled over much of the Pine Island and Thwaites glacier catchments from radar-detected isochrones, to constrain paleo simulations from the three-dimensional ice-sheet model PISM. We present initial results and assess the mismatches that exist between the observed dated isochrones from the radar and the modelled isochrones obtained from our simulations, focusing primarily on the Last Glacial Maximum and Holocene period, a time during which the ice-sheet most likely transitioned into today's intergacial state in a non-linear fashion. We aim to refine the ice-sheet model’s parameters based on this mismatch analysis in isochrone elevations, thus providing us with a spatially constrained evolution of the two glacier catchments that go beyond the typical one-dimensional constraints used so far over the WAIS.