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| Meckler, A. Nele; Haug, Gerald H.; Sigman, Daniel M.; Plessen, Birgit; Peterson, Larry C.; Thierstein, Hans R.. |
| For the last deglaciation and Termination V ( the initiation of MIS 11 at around 430 ka) we report high-resolution sedimentary nitrogen isotope (delta(15)N)records from Cariaco Basin in the Caribbean Sea. During both terminations the previously reported interglacial decrease in delta(15)N clearly lags local changes such as water column anoxia as well as global increases in denitrification by several thousand years. On top of the glacial-interglacial change, several delta(15)N peaks were observed during the last deglaciation. The deglacial signal in Cariaco Basin can be best explained as a combination of (1) local variations in suboxia and water column denitrification as the reason for the millennial-scale peaks, (2) a deglacial maximum in mean ocean... |
| Tipo: Text |
Palavras-chave: Cariaco Basin; N fixation; Deglaciation. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34457/32869.pdf |
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| Meckler, A. Nele; Ren, Haojia; Sigman, Daniel M.; Gruber, Nicolas; Plessen, Birgit; Schubert, Carsten J.; Haug, Gerald H.. |
| Constraining variations in marine N(2)-fixation over glacial-interglacial timescales is crucial for determining the role of the marine nitrogen cycle in modifying ocean productivity and climate, yet paleo-records from N2-fixation regions are sparse. Here we present new nitrogen isotope (delta(15)N) records of bulk sediment and foraminifera test-bound (FB) nitrogen extending back to the last ice age from the oligotrophic Gulf of Mexico (GOM). Previous studies indicate a substantial terrestrial input during the last ice age and early deglacial, for which we attempt to correct the bulk sediment delta(15)N using its observed relationship with the C/N ratio. Both corrected bulk and FB-delta(15)N reveal a substantial glacial-to-Holocene decrease of delta(15)N... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33786/32567.pdf |
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