DEGLACIAL SEA-LEVEL RECORD FROM TAHITI CORALS AND THE TIMING OF GLOBAL MELTWATER DISCHARGE

THE timing of the last deglaciation is important to our understanding of the dynamics of large ice sheets(1) and their effects on the Earth' s surface(2,3). Moreover, the disappearance of the glacial ice sheets was responsible for dramatic increases in freshwater fluxes to the oce ans, which probably disturbed the ocean's thermohaline circulation and , hence, global climate(4-7). Sea-level increases bear witness to the melting of continental ice sheets, but only two such records-from Barb ados(8,9) and New Guinea(10,11) corals-have been accurately dated. But these corals overlie active subduction zones, where tectonic movement s are large and often discontinuous (especially in New Guinea), so the apparent sea-level records may be contaminated by a complex tectonic component. Here we date fossil corals from Tahiti, which is far from p late boundaries (and thus Is likely to be tectonically relatively stab le) and remote from the locations of large former ice sheets. The resu lting record indicates a large sea-level jump shortly before 13,800 ca lendar years sp, which corresponds to meltwater pulse 1A in the Barbad os coral records(8,9). The timing of this event is more accurately con strained in the Tahiti record, revealing that the meltwater pulse coin cides with a short and intense climate cooling event(12-15) that follo wed the initiation of the Bolling-Allerod warm period(12-16), but prec eded the Younger Dryas cold event by about 1,000 years.