Sensitive response of the Greenland Ice Sheet to surface melt drainage over a soft bed

TitleSensitive response of the Greenland Ice Sheet to surface melt drainage over a soft bed
Publication TypeJournal Article
Year of Publication2014
AuthorsBougamont M., Christoffersen P., Hubbard A.L, Fitzpatrick A.A, Doyle S.H, Carter S.P
JournalNature Communications
Date Published2014/09
Type of ArticleArticle
ISBN Number2041-1723
Accession NumberWOS:000343029100001
Keywordsablation zone; b; basal mechanics; flow; outlet glacier; russell glacier; sea-level rise; stream; subglacial drainage; supraglacial lake; west greenland

The dynamic response of the Greenland Ice Sheet (GrIS) depends on feedbacks between surface meltwater delivery to the subglacial environment and ice flow. Recent work has highlighted an important role of hydrological processes in regulating the ice flow, but models have so far overlooked the mechanical effect of soft basal sediment. Here we use a three-dimensional model to investigate hydrological controls on a GrIS soft-bedded region. Our results demonstrate that weakening and strengthening of subglacial sediment, associated with the seasonal delivery of surface meltwater to the bed, modulates ice flow consistent with observations. We propose that sedimentary control on ice flow is a viable alternative to existing models of evolving hydrological systems, and find a strong link between the annual flow stability, and the frequency of high meltwater discharge events. Consequently, the observed GrIS resilience to enhanced melt could be compromised if runoff variability increases further with future climate warming.

Short TitleNat. Commun.
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