HR: 14:10h
AN: PP43C-03    [Abstracts]
TI: Greenland ice Cores tell Tales on the Eemian Period and Beyond
AU: * Dahl-Jensen, D
EM: ddj@gfy.ku.dk
AF: Niels Bohr Insitute, Juliane Maries Vej 30, Copenhagen OE, 2100 Denmark
AU: Bennike, O
EM: obe@geus.dk
AF: Geological Survey of Denmark and Greenland (GEUS), Oester Voldgade 10, Copenhagen K, 1350 Denmark
AU: Willerslev, E
EM: ewillerslev@gfy.ku.dk
AF: Niels Bohr Insitute, Juliane Maries Vej 30, Copenhagen OE, 2100 Denmark
AB: The deep NGRIP ice core from North Greenland (75N, 42W) is 3090m deep and reaches 125.000 years back in time. The climate record has an extremely high resolution with annual layers of the order of 1 cm right down to the base because basal melt reduces the thinning of the basal layers. The lowest 60 m of the ice core contains ice from the last interglacial period, the Eemian period (OIS-5e) and it is seen from the stable isotopes that the period was 5 deg C warmer in Greenland than our present interglacial period and very stable. The transition to glacial conditions occurred gradually over several thousand years. The NGRIP ice core contains the first undisturbed record of the Eemian period from the North Atlantic region. The NGRIP results contribute with a fix point in the predictions for sea level rise from a globale warming: a 5 deg warming over Greenland corresponds to the global sealevel rise of 5 m as that observed during the Eemian period. To evaluate the area and volume of the Greenland Ice Sheet during the Eemian period, it is worth noting that we find Eemian ice in the Dye3 ice core in South Greenland, in the central Greenland Ice cores GRIP and GISP2, in NGRIP and in the little 350m thich ice cap, Renland, on the east coast of Greenland. It can directly be concluded that the there was an significant ice sheet covering Greenland during the warm Eemian period and that the reduction of the Greenland ice sheet at most contributed with a sea level rise of 1-2 m of the observed 5 m. At the melting base of the NGRIP ice core two macroscopic plant remains were recovered. One is a wood fragment of willow (Salix) and the other is a fragment of a bud scale, probably also from willow. Also a few tiny fragments of spruce or larch (Picea/Larix) were found found. The fragments cannot be identified at the species level, but willow, spruce and larch remains are common in the Kap Kobenhavn Formation, dated to around 2.4 Ma BP. The Greenland Ice Sheet did not exist when the Kap Kobenhavn Formation was deposited, as shown by the occurrence of numerous warmth demanding plants and animals.
DE: 0724 Ice cores (4932)
DE: 0726 Ice sheets
DE: 0776 Glaciology (1621, 1827, 1863)
DE: 1630 Impacts of global change (1225)
DE: 1641 Sea level change (1222, 1225, 4556)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005