Modelling the evolution of Dronning Maud Land, Antarctica across the last interglacial-glacial cycle – insights from isochrone modelling.

Reconstructions of Antarctica's past ice-sheet evolution remain poorly constrained due to sparse, spatially discontinuous proxies, limiting accurate projections of its future sea-level contribution. Here we present a novel isochronally-constrained reconstruction of Dronning Maud Land (DML), East Antarctica spanning the last interglacial-glacial cycle (~130 kyr), integrating extensive radar-derived internal reflection horizons (IRHs) with PISM ice-sheet simulations.

IRHs preserve continuous records of past accumulation, flow, and basal conditions, providing unprecedented spatiotemporal constraints for model validation. Our ensemble simulations indicate that DML’s sea-level potential change between interglacial and glacial states is comparable to, and likely larger than, the contribution of all modern mountain glaciers, and show that variations in geothermal flux alone can substantially alter sea-level projections. These results provide physical modelling context of East Antarctica's ice history, reveal DML's role in Last Interglacial sea-level rise, and highlight persistent parameterization uncertainties limiting future projections.