Quaternary Arctic Ocean sea ice variations and radiocarbon reservoir age corrections

• Published in: Quaternary Science Reviews
• Main Authors: Hanslik, D., Jakobsson, M., Backman, J., Bjorck, S., Sellen, E., O'Regan, Matthew, Fornaciari, E., Skog, G.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 2010
• Subjects: QE Geology; Arctic; Arctic Ocean; Foraminifera*; Lomonosov Ridge; Neogloboquadrina pachyderma; North Atlantic; Sea ice
• Online Access: https://orca.cardiff.ac.uk/id/eprint/7544/; https://doi.org/10.1016/j.quascirev.2010.06.011

A short sediment core from a local depression forming an intra basin on the Lomonosov Ridge, was retrieved during the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX). It contains a record of the Marine Isotope Stages (MIS) 1e3 showing exceptionally high abundances of calcareous microfossils during parts of MIS 3. Based on radiocarbon dating, linear sedimentation rates of 7e9 cm/ka persist during the last deglaciation. The Last Glacial Maximum (LGM) is partly characterized by a hiatus. Planktic foraminiferal abundance variations of Neogloboquadrina pachyderma sinistral and calcareous nannofossils reflect changes in Arctic Ocean summer sea ice coverage and probably inflow of subpolar North Atlantic water. Calibration of the radiocarbon ages, using modeled reservoir corrections from previous studies and the microfossil abundance record of the studied core, results in marine reservoir ages of 1400 years or more, at least during the last deglaciation. Paired benthiceplanktic radiocarbon dated foraminiferal samples indicate a slow decrease in age difference between surface and bottom waters from the Lateglacial to the Holocene, suggesting circulation and ventilation changes.