The primary Antarctic contribution to modern sea-level rise is glacial discharge from the Amundsen Sea sector of the West Antarctic Ice Sheet. The main processes responsible for ice mass loss are ocean-driven melting of ice shelves and atmospheric-driven surface melting of glaciers. Using a beryllium isotope-based reconstruction of ice-shelf history, the study demonstrates that glaciers flowing into the Amundsen Sea Embayment underwent melting and retreat between 9 and 6 thousand years ago. This melting event was primarily driven by atmospheric circulation changes linked to tropical Pacific Ocean warming, despite the influence of warm ocean water. This millennial-scale glacial history can validate contemporary ice-sheet models and improve sea-level projections.

Adam D. Sproson, Yusuke Yokoyama, Yosuke Miyairi, Takahiro Aze, Rebecca L. Totten