THE INFLUENCE OF THE NORTH ATLANTIC CURRENT ON EUROPEAN ENVIRONMENTS DURING THE LAST INTERGLACIAL

To examine the influence of the North Atlantic circulation on European environments a correlation of last interglacial marine and terrestrial records was undertaken by an event-stratigraphic approach.

The major cold event after the last interglacial, i.e. C24, is clearly expressed in both marine and terrestrial records. In SST records this event is documented by the major peak abundance of IRD and N. pachyderma sinistral at the end of substage 5d. In terrestrial pollen records C24 is identified by the peak abundance of steppic taxa during the Herning stadial. The impact of the major cold event previous to the interglacial, i.e. Heinrich 11, is expressed in marine records by the peak abundance of IRD at the transition from MIS 6 to 5. In terrestrial pollen records the effect of H11 is recognized by peak abundance of steppic taxa right before the start of reforestation. Depths interpreted as showing the impact of C24, are assigned an age of 107 ka and depths which show the impact of H11 are assigned to 128 ka. Ages after Shackleton et al. (2002) are based on marine core MD95 2042. Events in the interval between C 24 and H 11 were tentatively dated on the assumption of uniform deposition rate.

The results show during the interglacial between 115 and 126 ka, the warming influence of the North Atlantic current (NAC) extended as far as 70ĒŠN to the Nordic Sea. For this period European pollen records indicate that the polar timberline was at ca. 69ĒŠN in Scandinavia and the northern boundary of thermophilous deciduous dominated woods at ca. 61ĒŠN. A major shift took place about 115 ka, which is labeled C26. The marine records show that the warming influence of the NAC did not extend to the Nordic Sea but still influenced sites in the subpolar North Atlantic. The response of European vegetation was an immediate southward push of the polar timberline to latitudes of northern Germany at ca. 53ĒŠN and the boundary of thermophilous deciduous dominated woods to ca. 48ĒŠ. These results show that European environments respond directly to changes in North Atlantic circulation.