Records and Processes of Near-Bottom Sediment Transport along the Norwegian-Greenland Sea Margins during Holocene and Late Weichselian (Termination I) Times

Acoustic mapping and sampling of Holocene and Late Weichselian deglacial sediments combined with oceanographic measurements in the sediment source and accumulation areas on the eastern continental margin of the Norwegian-Greenland Sea provide evidence that episodic transport towards high-accumulation areas is primarily downslope and gravity driven. Triggered by various hydrographic conditions, the runoff repeatedly followed the local gullies and channels of the seafloor.In contrast, sedimentological and oceanographic data from a topographic sediment trap on the Vøring Plateau at the Norwegian Sea margin indicate upslope sediment transport in the bottom nepheloid layer.Less comprehensive data from the Greenland Sea margin suggest that the prerequisites to sediment advection in terms of oceanographic structure, availability and sources of sediment differ from those of the eastern margin. The resulting near-bottom sediment transport is less pronounced. Advected sediments reaching the continental rise and the abyssal plain follow an old channel system.The forcing mechanisms of sediment advection changed dramatically from Late Weichselian to Holocene times due to changes in sea level, sediment availability, and water-mass stratification.