Age models of sediment cores from the Southern Ocean ...
Recent geochemical models invoke ocean alkalinity changes, particularly in the surface Southern Ocean, to explain glacial age pCO2 reduction. In such models, alkalinity increases in glacial periods are driven by reductions in North Atlantic Deep Water (NADW) supply, which lead to increases in deep-w...
| Main Authors: | , |
|---|---|
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA
1994
|
| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.733763 https://doi.pangaea.de/10.1594/PANGAEA.733763 |
| Summary: | Recent geochemical models invoke ocean alkalinity changes, particularly in the surface Southern Ocean, to explain glacial age pCO2 reduction. In such models, alkalinity increases in glacial periods are driven by reductions in North Atlantic Deep Water (NADW) supply, which lead to increases in deep-water nutrients and dissolution of carbonate sediments, and to increased alkalinity of Circumpolar Deep Water upwelling in the surface Southern Ocean. We use cores from the Southeast Indian Ridge and from the deep Cape Basin in the South Atlantic to show that carbonate dissolution was enhanced during glacial stages in areas now bathed by Circumpolar Deep Water. This suggests that deep Southern Ocean carbonate ion concentrations were lower in glacial stages than in interglacials, rather than higher as suggested by the polar alkalinity model [Broecker and Peng, 1989, doi:10.1029/GB001i001p00015]. Our observations show that changes in Southern Ocean CaCO3 preservation are coherent with changes in the relative flux of ... : Supplement to: Howard, William R; Prell, Warren L (1994): Late Quaternary CaCO3 production and preservation in the Southern Ocean: Implications for oceanic and atmospheric carbon cycling. Paleoceanography, 9(3), 453-482 ... |
|---|