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Clim. Past Discuss., 3, 409-433, 2007
www.clim-past-discuss.net/3/409/2007/
© Author(s) 2007. This work is licensed
under a Creative Commons License.

Synchronisation of the EDML and EDC ice cores for the last 52 kyr by volcanic signature matching

M. Severi1, S. Becagli1, E. Castellano1, A. Morganti1, R. Traversi1, R. Udisti1, U. Ruth2, H. Fischer2, P. Huybrechts2,7, E. Wolff3, F. Parrenin4, P. Kaufmann5, F. Lambert5, and J. P. Steffensen6
1Department of Chemistry, University of Florence, Florence, Italy
2Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, Germany
3British Antarctic Survey, Cambridge, UK
4Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS and Joseph Fourier University, Grenoble, France
5Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
6Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
7Departement Geografie, Vrije Universiteit Brussel, Brussels, Belgium

Abstract. A common time scale for the EPICA ice cores from Dome C (EDC) and Dronning Maud Land (EDML) was established. Since EDML core was not drilled on a dome, the development of the EDML1 time scale for the EPICA ice core drilled in Dronning Maud Land was carried on by creating a detailed stratigraphic link between this core and the one drilled at Dome C, dated by a simpler 1D ice-flow model. The synchronisation between the two ice cores was built via the identification of several common volcanic signatures. This paper describes the rigorous method, using the signature of volcanic sulfate, which was employed for the last 52 kyr of the record. By evaluating the ratio R of the apparent duration of temporal intervals between couples of isochrones, the depth comparison between the two cores was turned into an estimate of anomalies between the modelled EDC and EDML glaciological age models during the studied period. On average R ranges between 0.8 and 1.2 corresponding to an uncertainty within 20% in the estimate of the time duration in at least one of the two ice cores. Significant deviations of R up to 1.4–1.5 are observed between 18 and 28 kyr BP. At this step our approach is not able to unequivocally find out which of the models is affected by the errors, but assuming the thinning function at both sites and accumulation history at Dome C, which was drilled on a dome, as being correct, this anomaly can be ascribed to a complex spatial accumulation variability (which may be different at present day and in the past) and to upstream ice flow in the area of the EDML core.

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Citation: Severi, M., Becagli, S., Castellano, E., Morganti, A., Traversi, R., Udisti, R., Ruth, U., Fischer, H., Huybrechts, P., Wolff, E., Parrenin, F., Kaufmann, P., Lambert, F., and Steffensen, J. P.: Synchronisation of the EDML and EDC ice cores for the last 52 kyr by volcanic signature matching, Clim. Past Discuss., 3, 409-433, 2007.   Bibtex   EndNote   Reference Manager

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