Greenland palaeo-temperatures derived from the GRIP ice coreIn: Solar output and climate during the Holocene. Special Issue: ESF Project, European Palaeoclimate and Man II, p. 35-50, 1996
W. Dansgaard, S.J. Johnsen, H.B. Clausen, N. Gundestrup and C.U. Hammer
Geofysisk Afdeling, Niels Bohr Instituttet for Astronomi, Fysik og Geofysik, Københavns Universitet
A new 3029 m long deep ice core to bedrock has been drilled at the very top of the Greenland ice sheet (Summit) by the Greenland Ice-Core Project (GRIP), a European joint effort organized by the European Science Foundation. The ice core reaches back to 250 kyr B.P. according to dating based partly on stratigraphic methods and partly on ice-flow modelling. A continuous and extremely detailed stable isotope (δ18O) profile along the entire core depicts dramatic temperature changes in Greenland through the last two glacial periods, according to a time scale calculated by ice-flow modelling. Prior to 11 kyr B.P. the record is dominated by abrupt and irregular shifts, corresponding to temperature changes of 5o to 10oC, under glacial and maybe also under interglacial conditions. No less than 24 glacial interstadials have been identified in Weichselian ice, some of them are tentatively correlated to European interstadials. The shifts are associated with changes of the atmosphere/ocean circulation pattern in the North Atlantic Ocean. The Eem/Sangamon interglacial apparently elapsed completely in Greenland and Europe, perhaps because the Greenland climate was influenced by a strong and varying East Greenland Current, whereas Europe was permanently shielded by a strong Gulf Current displaced closer to western Europe than now.