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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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Addison, Jason A.; Finney, Bruce P.; Dean, Walter E.; Davies, Maureen H.; Mix, Alan C.; Stoner, Joseph S.; Jaeger, John M.. |
Biogenic opal, organic carbon, organic matter stable isotope, and trace metal data from a well-dated, high-resolution jumbo piston core (EW0408-85JC; 59 degrees 33.3'N, 144 degrees 9.21'W, 682 m water depth) recovered from the northern Gulf of Alaska continental slope reveal changes in productivity and nutrient utilization over the last 17,000 years. Maximum values of opal concentration (similar to 10%) occur during the deglacial Bolling-Allerod (B-A) interval and earliest Holocene (11.2 to 10.8 cal ka BP), moderate values (similar to 6%) occur during the Younger Dryas (13.0 to 11.2 cal ka BP) and Holocene, and minimum values (similar to 3.5%) occur during the Late Glacial Interval (LGI). When converted to opal mass accumulation rates, the highest values... |
Tipo: Text |
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Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00266/37680/36920.pdf |
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Praetorius, Summer K.; Condron, Alan; Mix, Alan C.; Walczak, Maureen H.; Mckay, Jennifer L.; Du, Jianghui. |
Columbia River megafloods occurred repeatedly during the last deglaciation, but the impacts of this fresh water on Pacific hydrography are largely unknown. To reconstruct changes in ocean circulation during this period, we used a numerical model to simulate the flow trajectory of Columbia River megafloods and compiled records of sea surface temperature, paleo-salinity, and deep-water radiocarbon from marine sediment cores in the Northeast Pacific. The North Pacific sea surface cooled and freshened during the early deglacial (19.0-16.5 ka) and Younger Dryas (12.9-11.7 ka) intervals, coincident with the appearance of subsurface water masses depleted in radiocarbon relative to the sea surface. We infer that Pacific meltwater fluxes contributed to net Northern... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72288/71102.pdf |
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