Quantitative Sub-Ice and Marine Tracing of Antarctic Sediment Provenance (TASP v0.1)

Abstract. Ice sheet models must be able to accurately simulate palaeo ice sheets to have confidence in their predictions of future Antarctic ice mass loss and resulting global sea-level rise, particularly over longer timescales. This requires accurate reconstructions of the extent and flow patterns of palaeo ice sheets using real-world data. Such reconstructions can be achieved by tracing the detrital components of offshore sedimentary records back to their source areas on land. However, sediment provenance data and ice sheet model results have not been directly linked, despite the complimentary information each can provide the other. Here, we present a computational framework (Tracing Antarctic Sediment Provenance, TASP) that predicts marine geochemical sediment provenance data using the output of numerical ice sheet modelling. The ice sheet model is used to estimate the spatial pattern of erosion rates and to trace ice flow pathways. Beyond the ice sheet margin, simple approximations of modern detrital particle transport mechanisms using ocean reanalysis data produce a good agreement between our predictions for the modern ice sheet/ocean system and marine surface sediments. Comparing results for the modern system to seafloor surface sediment measurements will allow application of the method to past ice sheet configurations. TASP currently predicts neodymium isotope compositions using the PSUICE3D ice sheet model, but it has been designed so that it could be adapted to predict other provenance indicators or use outputs of other ice sheet models.