The influence of meltwater on the Labrador Current in Heinrich event 1 and the Younger Dryas

Abstract

The Labrador Current transports freshwater from the Arctic regions to the northern Atlantic and the freshwater flux can influence the meridional overturning circulation. The response of the Labrador Current to meltwater processes is unclear during the deglaciation of the ice sheets around the northwest Atlantic. This study utilized cores from Flemish Pass to monitor variations in the strength of the Labrador Current by using the sortable-silt proxy. The carbonate content, the amount of ice-rafted detritus and XRF chemical data were measured to identify the main meltwater events during the last deglaciation. This study observed a clear enhancement of the flow strength of the Labrador Current in Heinrich Event 1 and the Younger Dryas, with the greatest flow strength during the Younger Dryas event. The onset of the current enhancement was dated at ca 13 cal ka BP, which preceded the enhanced ice-rafted deposition in Hudson Strait by about one thousand years. The current enhancement in Flemish Pass during the Younger Dryas event corresponds to the freshening of the surface water. Thus meltwater preceding significant iceberg supply has an important effect on the Labrador Current in Heinrich events on the Laurentide Ice Sheet margin.