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| Schmittner, Andreas; Bostock, Helen C.; Cartapanis, Olivier; Curry, William B.; Filipsson, Helena L.; Galbraith, Eric D.; Gottschalk, Julia; Carlos Herguera, Juan; Hoogakker, Babette; Jaccard, Samuel L.; Lisiecki, Lorraine E.; Lund, David C.; Martinez-mendez, Gema; Lynch-stieglitz, Jean; Mackensen, Andreas; Michel, Elisabeth; Mix, Alan C.; Oppo, Delia W.; Peterson, Carlye D.; Repschlaeger, Janne; Sikes, Elisabeth L.; Spero, Howard J.; Waelbroeck, Claire. |
| The carbon isotope composition (C-13) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the C-13 of foraminifera tests. Here more than 1700 C-13 observations of the benthic foraminifera genus Cibicides from late Holocene sediments (C-13(Cibnat)) are compiled and compared with newly updated estimates of the natural (preindustrial) water column C-13 of dissolved inorganic carbon (C-13(DICnat)) as part of the international Ocean Circulation and Carbon Cycling (OC3) project. Using selection criteria based on the spatial distance between samples, we find high correlation between C-13(Cibnat) and C-13(DICnat), confirming earlier work. Regression analyses indicate... |
| Tipo: Text |
Palavras-chave: Carbon; Isotopes; Benthic; Foraminifera; Calibration. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00661/77326/78788.pdf |
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| Schiraldi, Benedetto, Jr.; Sikes, Elisabeth L.; Elmore, Aurora C.; Cook, Mea S.; Rose, Kathryn A.. |
| This study examined sources of mixed layer and shallow subsurface waters in the subtropical Bay of Plenty, New Zealand, across the last deglaciation (similar to 30-5 ka). delta O-18 and delta C-13 from planktonic foraminifera Globgerinoides bulloides and Globorotalia inflata in four sediment cores were used to reconstruct surface mixed layer thickness, delta O-18 of seawater (delta O-18(SW)) and differentiate between high-and low-latitude water provenance. During the last glaciation, depleted planktonic delta O-18(SW) and enriched delta C-13 (-0.4-0.1 parts per thousand) indicate surface waters had Southern Ocean sources. A rapid delta C-13 depletion of similar to 1 parts per thousand in G. bulloides between 20 and 19 ka indicates an early, permanent shift... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40132/39242.pdf |
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| Clementi, Vincent J.; Sikes, Elisabeth L.. |
| Lower atmospheric CO2 concentrations during the Last Glacial Maximum (LGM; 23.0‐18.0 ka) have been attributed to the sequestration of respired carbon in the ocean interior, yet the mechanism responsible for the release of this CO2 during the deglaciation remains uncertain. Here, we present calculations of vertical differences in oxygen and carbon isotopes (∆δ18O and ∆δ13C, respectively) from a depth transect of southwest Pacific Ocean sediment cores to reconstruct changes in water mass structure and CO2 storage. During the LGM, ∆δ18O indicates a more homogenous deep Pacific below 1100 m, whereas regional ∆δ13C elucidates greater sequestration of CO2 in two distinct layers: enhanced CO2 storage at intermediate depths between ~940 m and 1400 m, and... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00488/59920/63110.pdf |
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