The 8.2 ka cooling event related to extensive melting of the Greenland Ice Sheet
H. Ebbesen1, A. Kuijpers1, M. Moros2, J. Lloyd3, M.-S. Seidenkrantz4, and S. Troelstra51Geological Survey of Denmark and Greenland, Denmark 2Institute for Baltic Sea Research, Warnemünde, Germany 3Department of Geography, University of Durham, UK 4Institute of Geology, Aarhus University, Denmark 5Department of Paleoclimatology and Geomorphology, Vrije Universiteit, The Netherlands
Received: 03 Sep 2008 – Discussion started: 27 Oct 2008
Abstract. The North Atlantic cooling event at 8200 calibrated (cal) yr BP has been attributed to effects of an extensive freshwater discharge from the Hudson Strait (Barber et al., 1999; Leverington et al., 2002). Here we present sedimentary records from 5 cores collected from the Greenland shelf. These document high magnetic susceptibility (MS) values related to massive silt deposition, which is ascribed to large-scale melt water outflow from the Greenland Ice Sheet (GIS) spanning the centuries before 8200 cal yr BP and ending after 8000 cal yr BP. XRF trace element composition and foraminiferal fauna's provide additional evidence for excessive melt-water production, which can be related to early Holocene warming of the circum-Arctic region including Greenland. Planktonic foraminiferal fauna data from the southern Davis Strait indicate the widespread presence of negative salinity anomalies reaching far offshore Greenland. Significant freshening of surface waters around Greenland prior to 8200 cal yr BP must have led to a slowdown of the deep-water formation which thus implies that significant melting of the GIS should be taken into account when discussing driving mechanisms behind the 8200 cal yr BP cooling event.
Ebbesen, H., Kuijpers, A., Moros, M., Lloyd, J., Seidenkrantz, M.-S., and Troelstra, S.: The 8.2 ka cooling event related to extensive melting of the Greenland Ice Sheet, Clim. Past Discuss., 4, 1219-1235, doi:10.5194/cpd-4-1219-2008, 2008.