The δ 18 O record along the Greenland Ice Core Project deep ice core and the problem of possible Eemian climatic instability

Johnsen, Sigfús
Clausen, Henrik,
Dansgaard, Willi
Gundestrup, Niels
Hammer, Claus
Andersen, Uffe
Andersen, Katrine
Hvidberg, Christine
Dahl-Jensen, Dorthe
Steffensen, Jørgen
Shoji, Hitoshi
Sveinbjörnsdóttir, Árny
White, Jim
Jouzel, Jean
Fisher, David
Johnsen, Sigffis,

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Publication date

November 1997

DOI

10.1029/97JC00167

Publisher

American Geophysical Union (AGU)

Abstract

International audienceOver 70,000 samples from the 3029-m-long Greenland Ice Core Project (GRIP) ice core drilled on the top of the Greenland Ice Sheet (Summit) have been analyzed for •180. A highly detailed and continuous •80 profile has thus been obtained and is discussed in terms of past temperatures in Greenland. We also discuss a three-core stacked annual •80 profile for the past 917 years. The short-term (<50 years) variability of the annual •80 signal is found to be 1%o in the Holocene, and estimates for the coldest parts of the last glacial are 3%0 or higher. These data also provide insights into possible disturbances of the stratigraphic layering in the core which seems to be sound down to the onset of the Eemian. Spectral analysis...