Restricted impact of Holocene climate variations on the southern Greenland Ice Sheet

TY - JOUR

T1 - Restricted impact of Holocene climate variations on the southern Greenland Ice Sheet

AU - Larsen, Nicolaj Krog

AU - Kjær, Kurt H.

AU - Olsen, Jesper

AU - Funder, Svend Visby

AU - Kjeldsen, Kristian Kjellerup

AU - Nørgaard-Pedersen, Niels

PY - 2011/10

Y1 - 2011/10

N2 - We use an ice marginal "threshold lake", Lower Nordbosø, in southern Greenland to record episodes when the southern Greenland Ice Sheet (sGIS) was close to the present extent, represented by beds of clastic sediments whereas gyttja-deposition reflects periods when the glacier was behind the threshold, and no glacial meltwater input. The results show that the sedimentation was initiated at c. 10.6 cal ka BP when the ice margin had reached the present extent following the deglaciation. After this the ice margin remained close to the present extent until c. 6.9 cal ka BP when it retreated behind the threshold and first reappeared with a clear glacial signal at c. 3.0-2.8 cal. ka BP and from c. 0.5 cal ka BP until the present. An overall good correlation between clastic input into Lower Nordbosø and IRD events from Narsaq Sound suggests that they represent a general glacial proximity signal of the sGIS. Our data demonstrates that the sGIS behaved less vigorously to Holocene climate changes compared to previous reconstructions. The ice sheet only retreated behind the present ice extent from c. 6.9 to 3.0 cal ka BP and c. 2.8 to 0.5 cal ka BP in the mountainous southern Greenland, whereas the more sensitive low-lying Qassimiut lobe was behind its present margin from c. 9 ka until the Little Ice Age. Accordingly, the ice marginal behavior in southern Greenland is not only governed by climate changes but also strongly influenced by the local topographic setting.

AB - We use an ice marginal "threshold lake", Lower Nordbosø, in southern Greenland to record episodes when the southern Greenland Ice Sheet (sGIS) was close to the present extent, represented by beds of clastic sediments whereas gyttja-deposition reflects periods when the glacier was behind the threshold, and no glacial meltwater input. The results show that the sedimentation was initiated at c. 10.6 cal ka BP when the ice margin had reached the present extent following the deglaciation. After this the ice margin remained close to the present extent until c. 6.9 cal ka BP when it retreated behind the threshold and first reappeared with a clear glacial signal at c. 3.0-2.8 cal. ka BP and from c. 0.5 cal ka BP until the present. An overall good correlation between clastic input into Lower Nordbosø and IRD events from Narsaq Sound suggests that they represent a general glacial proximity signal of the sGIS. Our data demonstrates that the sGIS behaved less vigorously to Holocene climate changes compared to previous reconstructions. The ice sheet only retreated behind the present ice extent from c. 6.9 to 3.0 cal ka BP and c. 2.8 to 0.5 cal ka BP in the mountainous southern Greenland, whereas the more sensitive low-lying Qassimiut lobe was behind its present margin from c. 9 ka until the Little Ice Age. Accordingly, the ice marginal behavior in southern Greenland is not only governed by climate changes but also strongly influenced by the local topographic setting.

U2 - 10.1016/j.quascirev.2011.07.022

DO - 10.1016/j.quascirev.2011.07.022

M3 - Journal article

SN - 0277-3791

VL - 30

SP - 3171

EP - 3180

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

IS - 21-22

ER -