A 60 000 year Greenland stratigraphic ice core chronology A. Svensson1, K. K. Andersen1, M. Bigler1, H. B. Clausen1, D. Dahl-Jensen1, S. M. Davies2, S. J. Johnsen1, R. Muscheler3, F. Parrenin4, S. O. Rasmussen1, R. Röthlisberger5, I. Seierstad1, J. P. Steffensen1, and B. M. Vinther1,6 1Centre for Ice and Climate, Niels Bohr Institute, Univ. of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark 2Department of Geography, University of Wales Swansea, Singleton Park, Swansea, SA2 8PP, UK 3GeoBiosphere Science Centre, Quaternary Sciences, Lund University, Sölvegatan 12, 22362 Lund, Sweden 4Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS and Joseph Fourier University, Grenoble, France 5British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK 6Climate Research Unit, School of Environmental Sciences, University of East Anglia, NR47TJ, Norwich, UK
Abstract. The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on
annual layer counting of high-resolution records from Greenland ice cores.
Whereas the Holocene part of the time scale is based on various records from
the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely
based on NorthGRIP records. Here we present an 18 ka extension of the time
scale such that GICC05 continuously covers the past 60 ka. The new section
of the time scale places the onset of Greenland Interstadial 12 (GI-12) at
46.9±1.0 ka b2k (before year AD 2000), the North Atlantic Ash Zone
II layer in GI-15 at 55.4±1.2 ka b2k, and the onset of GI-17 at
59.4±1.3 ka b2k. The error estimates are derived from the accumulated
number of uncertain annual layers. In the 40–60 ka interval, the new time
scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 ka.
Assuming that the Greenland climatic events are synchronous with those
seen in the Chinese Hulu Cave speleothem record, GICC05 compares well to the
time scale of that record with absolute age differences of less than 800
years throughout the 60 ka period. The new time scale is generally in close
agreement with other independently dated records and reference horizons,
such as the Laschamp geomagnetic excursion, the French Villars Cave and the
Austrian Kleegruben Cave speleothem records, suggesting high accuracy of
both event durations and absolute age estimates.
Citation: Svensson, A., Andersen, K. K., Bigler, M., Clausen, H. B., Dahl-Jensen, D., Davies, S. M., Johnsen, S. J., Muscheler, R., Parrenin, F., Rasmussen, S. O., Röthlisberger, R., Seierstad, I., Steffensen, J. P., and Vinther, B. M.: A 60 000 year Greenland stratigraphic ice core chronology, Clim. Past, 4, 47-57, doi:10.5194/cp-4-47-2008, 2008.