Antarctic intermediate water circulation in the South Atlantic over the past 25,000years ...

• Main Authors: Howe, JNW, Piotrowski, AM, Oppo, DW, Huang, KF, Mulitza, S, Chiessi, CM, Blusztajn, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: marine geochemistry; geochemical tracers; abrupt/rapid climate change; Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.17863/cam.6375; https://www.repository.cam.ac.uk/handle/1810/261205

Antarctic Intermediate Water is an essential limb of the Atlantic meridional overturning circulation that redistributes heat and nutrients within the Atlantic Ocean. Existing reconstructions have yielded conflicting results on the history of Antarctic Intermediate Water penetration into the Atlantic across the most recent glacial termination. In this study we present leachate, foraminiferal, and detrital neodymium isotope data from three intermediate-depth cores collected from the southern Brazil margin in the South Atlantic covering the past 25kyr. These results reveal that strong chemical leaching following decarbonation does not extract past seawater neodymium composition in this location. The new foraminiferal records reveal no changes in seawater Nd isotopes during abrupt Northern Hemisphere cold events at these sites. We therefore conclude that there is no evidence for greater incursion of Antarctic Intermediate Water into the South Atlantic during either the Younger Dryas or Heinrich Stadial 1. We do, ...