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Ice-ocean interactions at the Northeast Greenland Ice stream (NEGIS) over the past 11,000 years

Lloyd, J. M.; Ribeiro, S.; Weckström, K.; Callard, L.; Ó Cofaigh, C.; Leng, M. J.; Gulliver, P.; Roberts, D. H.

Ice-ocean interactions at the Northeast Greenland Ice stream (NEGIS) over the past 11,000 years Thumbnail


Authors

J. M. Lloyd

S. Ribeiro

K. Weckström

L. Callard

C. Ó Cofaigh

P. Gulliver

D. H. Roberts



Abstract

Recent observations have identified increased mass loss from Greenland marine-terminating outlet glaciers (MTOG) with implications for global sea-level rise and wider ocean circulation. The flow of Atlantic-sourced waters to the Greenland margin is thought to be a major control on MTOG behaviour. Investigation of longer-term records of the role of Atlantic-sourced waters on MOTG dynamics are needed to improve understanding of potential future trends in MTOG behaviour. Here we present a multi-proxy study (benthic and planktic foraminifera, dinoflagellate cysts, diatoms, stable isotopes, sea ice biomarkers and sedimentological analyses) from core PS100-198 on the northeast Greenland shelf to investigate the interaction between the Northeast Greenland Ice Stream (NEGIS) and ocean circulation through the Holocene. Proximal glaciomarine conditions at the base of the core indicate deglaciation before 10.9 ka cal BP with the relatively warm Atlantic Water present through advection of the Return Atlantic Current (RAC) across the shelf. The advection of RAC increased through the early Holocene reaching peak subsurface warmth from 8 to 9 ka cal BP. Surface conditions at this time were characterised by heavy sea-ice cover. During the mid-to late Holocene (c. 7–2 ka cal BP) advection of RAC weakened with cooler subsurface waters, but with an amelioration of surface conditions characterised by seasonal sea ice. From c. 2 ka cal BP, during the late Holocene, surface conditions continued to improve with continued seasonal sea-ice cover while subsurface proxies record an increase in RAC advection. The last c. 100 years represent the most ameliorated surface conditions through the Holocene and with subsurface conditions as warm as the early Holocene peak. This coincided with the final break up of ice within 79N fjord and retreat of NEGIS to the Holocene minimum position. Current conditions, therefore, suggest the present-day ice shelf within 79N fjord is most likely susceptible to collapse in the near future. This study highlights the critical influence of Atlantic-sourced waters on the dynamics of major Greenland MTOGs.

Journal Article Type Article
Acceptance Date Mar 25, 2023
Online Publication Date Apr 17, 2023
Publication Date May 15, 2023
Deposit Date Apr 24, 2023
Publicly Available Date Apr 24, 2023
Journal Quaternary Science Reviews
Print ISSN 0277-3791
Electronic ISSN 1873-457X
Publisher Elsevier BV
Peer Reviewed Peer Reviewed
Volume 308
Article Number 108068
DOI https://doi.org/10.1016/j.quascirev.2023.108068
Keywords Holocene; Paleoceanography; Greenland; Foraminifera; Dinocysts; Sedimentology; Marine cores
Public URL https://nottingham-repository.worktribe.com/output/19993636
Publisher URL https://www.sciencedirect.com/science/article/pii/S0277379123001166

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