Protracted ocean circulation slowdown drove exceptional ice-sheet melting during ice age termination IV

Glacial terminations stand out for their high rates of sea-level rise, particularly duringmeltwater pulses. Termination IV (T-IV; ~340,000 years before present) is a prominent example, with sea level rising at up to ~5m per century. Due to sparse absolute age constraints on marine records, the causes for the high rates of sea-level rise at T-IV remain elusive. In this work, we provide a speleothemchronology fromnorthern Italy, which we transpose to North Atlantic marine records. We infer that the high T-IV sea-level rise rate likely relates to a feedback whereby protracted meltwater release caused enhanced ocean heat storage, followed by heat release upon circulation recovery, driving additional ice-sheet collapse. This analysis highlights the critical role of oceanic feedbacks in driving exceptional rates of sea-level rise during terminations.