The nature of deep overturning and reconfigurations of the silicon cycle across the last deglaciation
MICHEL, Elisabeth
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Paléocéanographie [PALEOCEAN]
< Leer menos
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Paléocéanographie [PALEOCEAN]
Idioma
EN
Article de revue
Este ítem está publicado en
Nature Communications. 2020-03-24, vol. 11, n° 1
Resumen en inglés
Changes in ocean circulation and the biological carbon pump have been implicated as the drivers behind the rise in atmospheric CO 2 across the last deglaciation; however, the processes involved remain uncertain. Previous ...Leer más >
Changes in ocean circulation and the biological carbon pump have been implicated as the drivers behind the rise in atmospheric CO 2 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 CO 2 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 and marked an interval of Si cycle reorganisation. By regulating the strength of the biological pump, the glacial-interglacial shift in the Si cycle may present an important control on Pleistocene CO 2 concentrations.< Leer menos
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