Northern-sourced water dominated the Atlantic Ocean during the Last Glacial Maximum

• DOI: 10.1130/g47628.1
• Publication Date: 2020-05-19T20:49:21Z
• Authors: F. Pöppelmeier; P. Blaser; M. Gutjahr; S.L. Jaccard; M. Frank; L. Max; J. Lippold
• Keywords: Last Glacial Maximum; Circumpolar deep water

Abstract Increased carbon sequestration in the ocean subsurface is commonly assumed to have been one of main causes responsible for lower glacial atmospheric CO2 concentrations. Remineralized must stored away from atmosphere thousands years, yet water mass structure accommodating such increased storage continues be debated. Here, we present new sediment-derived bottom-water neodymium isotope records that allow fingerprinting masses and provide a more complete picture Atlantic Meridional Overturning Circulation geometry during Last Glacial Maximum. These results suggest vertical meridional distribution only experienced minor changes since last ice age. In particular, find no compelling evidence supporting southern-sourced substantially expanding shallower depths farther into Northern Hemisphere than today, which had previously inferred stable (δ13C) reconstructions. We argue depleted δ13C values observed deep Northwest do not necessarily indicate presence water. Instead, these may represent northern-sourced with modern preformed were further modified downstream by remineralized carbon, facilitated sluggish circulation, corroborating previous evidence.