Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Results of GreenICE sediment core study

Sediment coring were undertaken in a hitherto unexplored part of the Arctic Ocean, the margin of the Lomonosov Ridge facing the Lincoln Sea. The aim of the GreenICE project was to study the structure and dynamics of the sea ice cover and attempt to relate these to longer-term records of climate variability retrieved from sediment cores. The main field work was carried out in May 2004 from an ice camp established by a Twin Otter aircraft on drifting sea ice c.170 km north of Alert, Arctic Canada.

The recovered sediment cores contain very well-preserved calcareous microfossils allowing the establishment of reliable age models and fix points for correlation with other interior Arctic Ocean late Quaternary records. The sediment records reveal new data on variable Arctic Ocean paleoceanographic conditions during the last two glacial-interglacial cycles (last 200.000 years BP). The planktic foraminifera assemblage record reveals high abundances of small subpolar T. quinqueloba in the early and late interval of marine isotope stage 5. The abundance peaks are assigned to substage 5e (last interglacial) and 5a (warm interstadial).

These data indicate that the area, which totay is heavily ice-covered, has undergone extended periods of a reduced summer sea ice cover during earlier warm periods. With respect to glacial conditions, increased ice rafted debris deposition in the area appear to be associated with glacial isotope stages 6, 4 and late 3. The results are of particular interest for testing of climate model results of Arctic Ocean conditions under global warming influence. Results of the sediment core study are published in peer-reviewed international journals.

Informations connexes

Reported by

Geological Survey of Denmark and Greenland, Dept. of Quaternary Geology
Oster Voldgade 10
1350 Copenhagen K
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