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Crosta, X; Shemesh, A; Etourneau, J; Yam, R; Billy, I; Pichon, Jj. |
Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Subantarctic Zone and the southern Subtropical Zone of the Indian Ocean. These records provide a latitudinal transect covering the main oceanographic systems of the Southern Ocean. Carbon and nitrogen content of the diatom-bound organic matter increases during the last glacial in the Antarctic and Subantarctic zones but does not show a clear climate-related signal in the Subtropical Zone. Comparison of these records with sea-surface temperatures reconstructed at the core locations and... |
Tipo: Text |
Palavras-chave: Diatoms; Nutrient cycling; Southern Ocean. |
Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00230/34075/32543.pdf |
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Crosta, X; Shemesh, A. |
[1] Oceanic nutrient cycling in the Southern Ocean is supposed to have an important impact on glacial-interglacial atmospheric CO(2) changes and global climate. In order to characterize such nutrient cycling over the last two climatic cycles we investigated carbon and nitrogen isotopic ratios of diatom-bound organic matter (delta(13)C(diat) and delta(15)N(diat)- respectively) in two cores retrieved form the Atlantic and Indian sectors of the Antarctic Ocean. The two cores show the same isotopic patterns. The delta(13)C(diat) values are depleted during glacial periods and enriched during interglacial periods, indicating lower productivity during cold times. The delta(15)N(diat) values are enriched during glacial periods and depleted during interglacial... |
Tipo: Text |
Palavras-chave: Southern Ocean; Paleoceanography; Geochemistry; Diatoms. |
Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33402/31859.pdf |
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