Decadal-scale onset and termination of Antarctic ice-mass loss during the last deglaciation

Emerging evidence suggests retreat of the Antarctic Ice Sheet (AIS) can persist considerably longer than the duration of the forcing. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and responses on century and longer timescales. New data from Iceberg Alley identifies eight retreat phases after the last Ice Age that de-stabilized the AIS within a decade, contributing to global sea-level rise for centuries to a millennium, which subsequently stabilized equally rapidly. New blue ice records and independent ice-sheet modeling demonstrate the dynamic response of the AIS included a step-wise retreat of up to 400 km across the Ross Sea, accompanied by ice elevation drawdown of the West Antarctic Ice Sheet (>600 m). Together, these long time series support studies that propose the recent acceleration of AIS mass loss may mark the beginning of a prolonged period of ice sheet retreat, associated with substantial global sea level rise.