Holocene thinning in central Greenland controlled by the Northeast Greenland Ice Stream

Ice-core records from the interior of the Greenland ice sheet suggest widespread thinning during the Holocene. However, the recurring underestimation of this thinning in numerical models raises concerns about both the veracity of such reconstructions and the reliability of glaciological models. Rece...

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Bibliographic Details
Published in:Nature communications 2024-07, Vol.15 (1), p.6434-12, Article 6434
Main Authors: Tabone, Ilaria, Robinson, Alexander, Montoya, Marisa, Alvarez-Solas, Jorge
Format: Article
Language:English
Subjects:
704/106/125
704/106/413
Cores
Deglaciation
Fast ice
Holocene
Humanities and Social Sciences
Ice
Ice sheets
Mathematical models
multidisciplinary
Numerical models
Science
Science (multidisciplinary)
Shear stress
Sheet modelling
Stream discharge
Stream flow
Thinning
Three dimensional flow
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Summary:Ice-core records from the interior of the Greenland ice sheet suggest widespread thinning during the Holocene. However, the recurring underestimation of this thinning in numerical models raises concerns about both the veracity of such reconstructions and the reliability of glaciological models. Recent work suggests the 8000-year-old Northeast Greenland Ice Stream (NEGIS), including a now-extinct northern tributary, may have been an early influence on Greenland ice-sheet dynamics. Yet, the inaccurate reproduction of NEGIS-like dynamics in most models hampers investigation of whether this feature played a role in Holocene ice-sheet thinning. Here we show that grounding-line retreat in northeast Greenland triggers elevation changes at the northern summit via ice-dynamic effects modulated by the paleo NEGIS system. In our simulations, fast ice-stream flow caused by transiently imposed reduced basal shear stress following the northeast retreat explains 55% ( ± 18%) of the estimated ice thinning, showing that ice-stream dynamics is one of the main drivers of the NGRIP Holocene surface elevation drop. Our findings show that the ice-flow in northeast Greenland plays a large role in ice-surface elevation changes in central Greenland. Using a three-dimensional ice sheet model, this work demonstrates that more than half of the Holocene surface elevation drop recorded in ice cores from north-central Greenland can be attributed to ice dynamic changes in northeast Greenland following ice-sheet retreat during the last deglaciation.
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-024-50772-5