What do benthic δ13C and δ18O data tell us about Atlantic circulation during Heinrich Stadial 1? ...

• Main Authors: Oppo, Delia W., Curry, William B., McManus, Jerry F.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2015
• Subjects: Paleoceanography; Glaciers > Climatic factors; Ocean circulation; Chemical oceanography; Paleoclimatology; Hydrology; NADW; North Atlantic Deep Water; North Atlantic; Northeast Atlantic
• Online Access: https://dx.doi.org/10.7916/d83j3csg; https://academiccommons.columbia.edu/doi/10.7916/D83J3CSG

Approximately synchronous with the onset of Heinrich Stadial 1 (HS1), δ13C decreased throughout most of the upper (~1000–2500 m) Atlantic, and at some deeper North Atlantic sites. This early deglacial δ13C decrease has been alternatively attributed to a reduced fraction of high-δ13C North Atlantic Deep Water (NADW) or to a decrease in the NADW δ13C source value. Here we present new benthic δ18O and δ13C records from three relatively shallow (~1450–1650 m) subpolar Northeast Atlantic cores. With published data from other cores, these data form a depth transect (~1200–3900 m) in the subpolar Northeast Atlantic. We compare Last Glacial Maximum (LGM) and HS1 data from this transect with data from a depth transect of cores from the Brazil Margin. The largest LGM-to-HS1 decreases in both benthic δ13C and δ18O occurred in upper waters containing the highest NADW fraction during the LGM. We show that the δ13C decrease can be explained entirely by a lower NADW δ13C source value, entirely by a decrease in the ...