The Holocene History of Nares Strait: Transition from Glacial Bay to Arctic-Atlantic Throughflow.

Jennings, Anne; Sheldon, Christina; Cronin, Thomas; Francus, Pierre; Stoner, Joseph et Andrews, John (2011). The Holocene History of Nares Strait: Transition from Glacial Bay to Arctic-Atlantic Throughflow. Oceanography , vol. 24 , nº 3. pp. 26-41. DOI: 10.5670/oceanog.2011.52.

Prévisualisation

PDF Télécharger (935kB) | Prévisualisation

Résumé

Retreat of glacier ice from Nares Strait and other straits in the Canadian Arctic Archipelago after the end of the last Ice Age initiated an important connection between the Arctic and the North Atlantic Oceans, allowing development of modern ocean circulation in Baffin Bay and the Labrador Sea. As low-salinity, nutrient-rich Arctic Water began to enter Baffin Bay, it contributed to the Baffin and Labrador currents flowing southward. This enhanced freshwater inflow must have influenced the sea ice regime and likely is responsible for poor calcium carbonate preservation that characterizes the Baffin Island margin today. Sedimentologic and paleoceanographic data from radiocarbon-dated core HLY03-05GC, Hall Basin, northern Nares Strait, document the timing and paleoenvironments surrounding the retreat of waning ice sheets from Nares Strait and opening of this connection between the Arctic Ocean and Baffin Bay. Hall Basin was deglaciated soon before 10,300 cal BP (calibrated years before present) and records ice-distal sedimentation in a glacial bay facing the Arctic Ocean until about 9,000 cal BP. Atlantic Water was present in Hall Basin during deglaciation, suggesting that it may have promoted ice retreat. A transitional unit with high ice-rafted debris content records the opening of Nares Strait at approximately 9,000 cal BP. High productivity in Hall Basin between 9,000 and 6,000 cal BP reflects reduced sea ice cover and duration as well as throughflow of nutrient-rich Pacific Water. The later Holocene is poorly resolved in the core, but slow sedimentation rates and heavier carbon isotope values support an interpretation of increased sea ice cover and decreased productivity during the Neoglacial period.

Type de document:	Article
Mots-clés libres:	radiocarbon age calibration; northernmost Baffin Bay; sea ice; innuitian ice; foraminiferal assemblages; benthic foraminifera; fresh water; greenland; ocean; shelf
Centre:	Centre Eau Terre Environnement
Date de dépôt:	29 nov. 2019 14:36
Dernière modification:	29 nov. 2019 14:36
URI:	https://espace.inrs.ca/id/eprint/9514

Gestion Actions (Identification requise)

Modifier la notice