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| Skinner, Lc; Shackleton, Nj. |
| A sequence of accelerator mass spectrometry (AMS) C-14 dates performed on benthic and planktonic foraminifera from a northeast Atlantic deep-sea core (MD99-2334K; 37degrees480N, 10degrees10'W; 3146 m) permit the reconstruction of deep water ,,C-14 ventilation ages'' across the last deglaciation. The records from MD99-2334K have been placed on the GISP2 timescale via the synchrony of temperature changes recorded in the Greenland ice cores and in North Atlantic planktonic delta(18)O(cc) (calcite delta(18)O). On the basis of a range of estimates for past source water Delta(14)C, this permits the estimation of C-14 projection ventilation ages for comparison with benthic-planktonic C-14 age differences. Although the accurate estimation of past ventilation ages... |
| Tipo: Text |
Palavras-chave: Termination I; Ventilation age; Thermohaline circulation. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33971/32339.pdf |
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| Devries, Tim; Primeau, Francois. |
| Existing methods for inferring the ventilation age of water masses in the ocean using radiocarbon data neglect the effects of diffusive mixing. in the presence of varying atmospheric Delta(14)C, this neglect produces spurious time dependence in the estimated ventilation ages. To correct this deficiency we propose a new method for estimating the ventilation age from sediment core radiocarbon data. The new method is formulated in terms of parameterized age distributions that account for the effects of advective and diffusive transport in the ocean. When applied to simulated radiocarbon data from an OGCM, the method is able to closely reproduce the modeled ventilation age, whereas other methods are not. We also applied the method to sediment-core radiocarbon... |
| Tipo: Text |
Palavras-chave: Ocean Drilling Program; Site 887; Ventilation age; Radiocarbon; Transit-time distribution; Glacial-interglacial. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00231/34197/32870.pdf |
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