Heinrich Event

A Heinrich event is an episode of massive iceberg discharge from the Laurentide Ice Sheet through Hudson Strait into the North Atlantic during the last glacial period. The armadas dropped ice-rafted debris that forms distinct lithic-rich layers in marine sediment cores. At least six events, H1 to H6, occurred between about 60,000 and 15,000 years ago, each lasting several hundred to about 1,000 years. The freshwater flux freshened surface waters, weakened North Atlantic Deep Water formation and the AMOC, and drove cooling, a mechanism shared with Dansgaard-Oeschger cycles.