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| Andersen, C; Koc, N; Moros, M. |
| A composite record (LO09-14) of three sediment cores from the subpolar North Atlantic (Reykjanes Ridge) was investigated in order to assess surface ocean variability during the last 11 kyr. The core site is today partly under the influence of the Irminger Current (IC), a branch of the North Atlantic Drift continuing northwestward around Iceland. However, it is also proximal to the Sub-Arctic Front (SAF) that may cause extra dynamic hydrographic conditions. We used statistical methods applied to the fossil assemblages of diatoms to reconstruct quantitative sea surface temperatures (SSTs). Our investigations give evidence for different regional signatures of Holocene surface oceanographic changes in the North Atlantic. Core LO09-14 reveal relatively low and... |
| Tipo: Text |
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| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/34003/32348.pdf |
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| Koc, N; Labeyrie, L; Manthe, S; Flower, Bp; Hodell, Da; Aksu, A. |
| Well-preserved diatoms are present in high sedimentation rate Pleistocene cores retrieved on ocean Drilling Program (ODP) Legs 151, 152, 162 and IMAGES cruises of RN Marion Dufresne from the North Atlantic. Investigation of the stratigraphic occurrence of diatom species shows that the youngest diatom event observed in the area is the last occurrence (LO) of Proboscia curvirostris (Jouse) Jordan and Priddle. P. curvirostris is a robust species that can easily be identified in the sediments, and therefore can be a practical biostratigraphic tool. We have mapped its: areal distribution, and found that it stretches from 40 degreesN to 80 degreesN in the North Atlantic. Further, we have correlated the LO P. curvirostris to the oxygen isotope records of six... |
| Tipo: Text |
Palavras-chave: Biostratigraphy; North Atlantic; Diatoms; Pleistocene; Paleoceanography; Isotope stratigraphy; Oxygen. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33210/31708.pdf |
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| Andersen, C; Koc, N; Jennings, A; Andrews, Jt. |
| High-resolution sediment cores from the Voring Plateau, the North Iceland shelf, and the East Greenland shelf have been studied to investigate the stability of major surface currents in the Nordic Seas during the Holocene. Results from diatom assemblages and reconstructed sea-surface temperatures (SSTs) indicate a division of the Holocene into three periods: the Holocene Climate Optimum (9500 - 6500 calendar (cal) years BP), the Holocene Transition Period ( 6500 - 3000 cal years BP) and the Cool Late Holocene Period ( 3000 - 0 cal years BP). The overall climate development is in step with the decreasing insolation on the Northern Hemisphere, but regional differences occur regarding both timing and magnitude of SST changes. Sites under the direct influence... |
| Tipo: Text |
Palavras-chave: Nordic Seas; Holocene; Sea-surface temperatures. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00226/33721/32134.pdf |
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