TY - JOUR
T1 - Early Holocene large-scale meltwater discharge from Greenland documented by foraminifera and sediment parameters
AU - Seidenkrantz, Marit-Solveig
AU - Ebbesen, Hanne
AU - Aagaard-Sørensen, Steffen
AU - Moros, Matthias
AU - Lloyd, Jeremy M.
AU - Olsen, Jesper
AU - Knudsen, Mads Faurschou
AU - Kuijpers, Antoon
PY - 2013/12/1
Y1 - 2013/12/1
N2 - Records of foraminiferal assemblages combined with lithological properties (grain size, magnetic parameters and XRF data) of marine sediment cores from West Greenland coastal waters and the adjacent Labrador Sea document widespread early Holocene meltwater discharge. This discharge is concluded to originate from large-scale melting of the Greenland Ice Sheet (GIS) having started prior to 8600. cal.yr. BP and ended at about 7700-7500. cal.yr. BP, when the GIS margin had withdrawn from the fjords and become mainly land-based. The benthic foraminiferal record from one of the coastal sites mainly reflects West Greenland Current (WGC) subsurface water properties and to a minor degree surface productivity. The most significant feature in this record is an abrupt shift to a higher-productivity regime around ~. 7700. cal.yr. BP. We suggest that the cessation of a widespread GIS meltwater discharge at that time favoured an increased influence of (sub)surface water of Atlantic origin and initiation of modern subpolar gyre circulation enabling Labrador Sea deep convection. Further offshore, a record of planktonic foraminiferal assemblages shows an oceanographic change at ca. 9500. cal.yr. BP, whilst a gradual but marked change in the planktonic foraminiferal assemblage between 8800 and 7000. cal.yr. BP may be related to a narrowing of the WGC low-salinity surface water belt. The oceanic regime off West Greenland prior to ~. 7800. cal.yr. BP was thus characterised by the presence of a permanent and widespread meltwater surface layer, presumably preventing deep convection in this region. Apart from indications of a slight decrease in meltwater discharge by the benthic foraminiferal fauna data, neither of the records show any clear signal of a regionally important 8.2. ka event.
AB - Records of foraminiferal assemblages combined with lithological properties (grain size, magnetic parameters and XRF data) of marine sediment cores from West Greenland coastal waters and the adjacent Labrador Sea document widespread early Holocene meltwater discharge. This discharge is concluded to originate from large-scale melting of the Greenland Ice Sheet (GIS) having started prior to 8600. cal.yr. BP and ended at about 7700-7500. cal.yr. BP, when the GIS margin had withdrawn from the fjords and become mainly land-based. The benthic foraminiferal record from one of the coastal sites mainly reflects West Greenland Current (WGC) subsurface water properties and to a minor degree surface productivity. The most significant feature in this record is an abrupt shift to a higher-productivity regime around ~. 7700. cal.yr. BP. We suggest that the cessation of a widespread GIS meltwater discharge at that time favoured an increased influence of (sub)surface water of Atlantic origin and initiation of modern subpolar gyre circulation enabling Labrador Sea deep convection. Further offshore, a record of planktonic foraminiferal assemblages shows an oceanographic change at ca. 9500. cal.yr. BP, whilst a gradual but marked change in the planktonic foraminiferal assemblage between 8800 and 7000. cal.yr. BP may be related to a narrowing of the WGC low-salinity surface water belt. The oceanic regime off West Greenland prior to ~. 7800. cal.yr. BP was thus characterised by the presence of a permanent and widespread meltwater surface layer, presumably preventing deep convection in this region. Apart from indications of a slight decrease in meltwater discharge by the benthic foraminiferal fauna data, neither of the records show any clear signal of a regionally important 8.2. ka event.
KW - 8.2ka event
KW - Early Holocene
KW - Foraminifera
KW - Greenland
KW - Magnetic susceptibility
KW - Meltwater discharge
KW - Sediment properties
UR - http://www.scopus.com/inward/record.url?scp=84888199893&partnerID=8YFLogxK
U2 - 10.1016/j.palaeo.2012.04.006
DO - 10.1016/j.palaeo.2012.04.006
M3 - Article
VL - 391
SP - 71
EP - 81
JO - Palaeogeography, Palaeoclimatology, Palaeoecology
JF - Palaeogeography, Palaeoclimatology, Palaeoecology
SN - 0031-0182
IS - Part A
ER -