Fig. 5: High δ18Osw-ivc signature reconstructed at multiple sites in the North Atlantic reveals the upstream pathway of glacial Northwest Atlantic deep waters.
From: Relatively warm deep-water formation persisted in the Last Glacial Maximum
a, Map showing the location of core sites used to reconstruct surface-ocean (red filled circles) and deep-ocean (blue filled circles) δ18Osw-ivc from the glacial North Atlantic (Methods, Extended Data Table 3 and references therein, and Source Data). The numbered star (11) denotes the approximate position of our Northwest Atlantic transect). The red and blue arrows denote surface- and deep-ocean currents, respectively. White shaded areas denote the approximate extent of the Laurentide Ice Sheet (LIS)49 and Feno-Scandinavian Sheet (FIS) and British-Irish Sheet (BIS)50 at 21.5 ka BP. GS, Gulf Stream. b, Simplified schematic showing the potential upstream pathway of high δ18Osw-ivc NADW (δ18Osw is reported relative to the SMOW scale). The numbers along the arrow correspond to the numbered core sites in a. For consistency and where necessary, both planktic and benthic Mg/Ca temperature data were recalibrated using new and/or updated calibrations and foraminiferal calcite (δ18Oc) was corrected using species-specific corrections14 (Methods and Source Data).
