Here we show how external oceanic forcing is a plausible driver of the enigmatic millennial-scale variability of the Laurentide ice sheet during the last glacial periods. We find excellent agreement when comparing ice discharge frequency from the ice-sheet model with proxy data for ice-rafted debris deposition the North Atlantic.

Laurentide ice sheet variability over the last glacial period as simulated by the ice-sheet model GRISLI forced by oceanic temperature anomalies.

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