Deep sea ventilation of the northeastern Atlantic during the last 15,000 years

Sea surface temperature and salinity estimates reconstructed from a core (56/-10/36) collected on the. Barra Fan, northwest Scotland (56 degrees 43 'N, 09 degrees 19 'W; water depth 1320 m) show a series of rapid oscillations during the last deglacial period that are very similar to those observed in the delta O-18 records from Greenland ice cores. These records indicate that the transport of heat and salt toward the Nordic Seas was highest during the Bolling period. A nearby deeper water core (57/-11/59) on the distal margin of the Barra Fan (57 degrees 01 'N, 10 degrees 01 'W, water depth 2089 m) allows us to study the response of the delta C-13 record of the benthic foraminifera Cibicidoides wuellerstorfi through the deglacial interval at a century/decadal scale. By comparing the sea surface temperature, salinity and benthic records at this site with other Atlantic Ocean records, we evaluate the timing of deep sea ventilation with changes in surface water characteristics. The benthic delta C-13 evidence suggests that NADW formation strengthened during the Bolling-Allerod period and ventilation was at least as strong as it has been for much of the Holocene. Maximum deep water formation was essentially coincident with the maximum northward transport of heat and salt, but predates the transition in delta C-13 Which is recorded in the deep western Atlantic. Deep water ventilation of this site was reduced during the Younger Dryas period. (C) 2001 Elsevier Science B.V. All rights reserved.