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. and Roberts, D.H. (2023) Ice-ocean interactions at the Northeast Greenland Ice stream (NEGIS) over the past 11,000 years. Quaternary Science Reviews, 308, 108068. (doi: 10.1016/j.quascirev.2023.108068)

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.

• Item Type: Articles
• Additional Information: We gratefully acknowledge support from AWI for ship time via grants AWI_PS100_01 and AWI_PS109_03. Guillaume Masse and Caroline Guilmette are kindly thanked for the IP25 data. This work was funded by NERC Standard Grant NE/N011228/1. Additional support was provided through the NERC National Environmental Isotope Facility for stable isotope analyses (grant IP-1816-0618, analyses performed by Hilary Sloane, BGS) and NERC Radiocarbon Facility NRCF010001 (allocation number 2113.0418). [...] SR received financial support from the Independent Research Council Denmark (grant nr. 9064-00039B) and KW from Arctic Avenue (spearhead research project between the University of Helsinki and Stockholm University).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gulliver, Dr Pauline

Creator Roles

Gulliver, P.: Formal analysis

• Authors: Lloyd, J.M., Ribeiro, S., Weckström, K., Callard, L., Ó Cofaigh, C., Leng, M.J., Gulliver, P., and Roberts, D.H.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Quaternary Science Reviews
• Publisher: Elsevier
• ISSN: 0277-3791
• ISSN (Online): 1873-457X
• Published Online: 17 April 2023
• Copyright Holders: Copyright: © 2023 The Authors
• First Published: First published in Quaternary Science Reviews 308: 108068
• Publisher Policy: Reproduced under a Creative Commons licence