Volcanic ash layers from the Last Glacial Termination in the NGRIP ice cores

Journal of Quaternary Science, Vol. 20, No. 3, doi:10.1002/jqs.908, 2005

A.K. Mortensen and K. Grönvold
Nordic Volcanological Institute, Grensa´svegur 50, 108 Reykjavik, Iceland.
M. Bigler
Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland.
J.P. Steffensen and S.J. Johnsen
Ice and Climate, The Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark

The tephrochronological record of the 1400-1640 m depth (~10 000-16 000 calendar ice core years before present) of the NGRIP ice core has been established by particle screening of selected samples. Ash was identified in 20 samples. Correlation with ice, marine and terrestrial records from volcanic source regions in the northern hemisphere positively identifies the Saksunarvatn Ash and the Vedde Ash (Ash Zone 1). Major element chemistry of the remaining identified ash layers mainly points towards an Icelandic origin. This tephrochronological record provides new important marker horizons for correlating the timing of the climatic changes associated with the Last Glacial Termination within the North Atlantic region, as well as outlining more details concerning the frequency and composition of volcanic eruptions occurring at this deglaciation.