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| Romero, O. E.; Crosta, X.; Kim, J. -h.; Pichevin, L.; Crespin, J.. |
| Although productivity variations in coastal upwelling areas are mostly attributed to changes in wind strength, productivity dynamics in the Benguela Upwelling System (BUS) is less straightforward due to its complex atmospheric and hydrographic settings. In view of these settings, past productivity variations in the BUS can be better investigated with downcore sediments representing different productivity regimes. In this study, two sediment cores retrieved at ca. 25°–26°S in the BUS and representing different productivity regimes were studied. By using micropaleontological, geochemical and temperature proxies measured on core MD96-2098, recovered at 2910 m water depth in the bathypelagic zone at 26°S off Namibia, variations of filament front location,... |
| Tipo: Text |
Palavras-chave: Benguela; Diatoms; Millennial and submillennial time scale; Productivity; Sea-surface temperature; SW Atlantic; Upwelling filaments. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40499/39432.pdf |
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| Dumont, M.; Pichevin, L.; Geibert, W.; Crosta, X.; Michel, E.; Moreton, S.; Dobby, K.; Ganeshram, R.. |
| Changes in ocean circulation and the biological carbon pump have been implicated as the drivers behind the rise in atmospheric CO2 across the last deglaciation; however, the processes involved remain uncertain. Previous records have hinted at a partitioning of deep ocean ventilation across the two major intervals of atmospheric CO2 rise, but the consequences of differential ventilation on the Si cycle has not been explored. Here we present three new records of silicon isotopes in diatoms and sponges from the Southern Ocean that together show increased Si supply from deep mixing during the deglaciation with a maximum during the Younger Dryas (YD). We suggest Antarctic sea ice and Atlantic overturning conditions favoured abyssal ocean ventilation at the YD... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/72971/72036.pdf |
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