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| De Garidel-thoron, T; Beaufort, L; Bassinot, F; Henry, P. |
| Past atmospheric methane-concentration oscillations recorded in polar ice cores vary together with rapid global climatic changes during the last glacial episode. In the "clathrate gun hypothesis," massive releases of deep-sea methane from marine gas-hydrate dissociation led to these well known, global, abrupt warmings in the past. If evidence for such releases in the water column exists, however, the mechanism and eventual transfer to the atmosphere has not yet been documented clearly. Here we describe a high-resolution marine-sediment record of stable carbon isotopic changes from the Papua Gulf, off Papua New Guinea, which exhibits two extremely depleted excursions (down to -9parts per thousand) at approximate to39,000 and approximate to55,000 years.... |
| Tipo: Text |
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| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00226/33734/32378.pdf |
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| De Garidel-thoron, T; Beaufort, L; Linsley, Bk; Dannenmann, S. |
| The primary productivity dynamics of the last 200,000 years in the Sulu Sea was reconstructed using the abundance of the coccolithophore Florisphaera profunda in the IMAGES MD97-2141 core. We find that primary productivity was enhanced during glacial periods, which we suggest is due to a stronger East Asian winter monsoon. During the last 80 kyr, eight significant increases in primary productivity (PP) in the Sulu Sea are similar to East Asian winter monsoon changes recorded in Chinese loess. The PP maxima are not linked with Heinrich events (HE) in the North Atlantic, although four PP peaks are synchronous with HE. The PP oscillations have frequencies near those of the Dansgaard-Oeschger cycles in Northern Hemisphere ice records and indicate a... |
| Tipo: Text |
Palavras-chave: Micropaleontology; Pacific Ocean. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33187/31809.pdf |
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