A high-resolution elemental record of post-glacial lithic sedimentation in Upernavik Trough, western Greenland: History of ice-sheet dynamics and ocean circulation changes over the last 9100 years
SAINT-ONGE, G.
Université du Québec à Rimouski [UQAR]
Centre de recherche sur la dynamique du système Terre [GEOTOP]
Université du Québec à Rimouski [UQAR]
Centre de recherche sur la dynamique du système Terre [GEOTOP]
MASSÉ, Guillaume
Variabilité de l'Océan et de la Glace de mer [LOCEAN-VOG]
Takuvik International Research Laboratory
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Variabilité de l'Océan et de la Glace de mer [LOCEAN-VOG]
Takuvik International Research Laboratory
Langue
EN
Article de revue
Ce document a été publié dans
Global and Planetary Change. 2020-08, vol. 191, p. 103217
Résumé en anglais
A better understanding of the past dynamics of local sectors of the Greenland ice sheet (GIS) with regards to ocean circulation and climate changes can be developed from proxy records derived from marine sedimentary archives. ...Lire la suite >
A better understanding of the past dynamics of local sectors of the Greenland ice sheet (GIS) with regards to ocean circulation and climate changes can be developed from proxy records derived from marine sedimentary archives. Here we investigate the post 9.1 cal. Kyr BP history of the western sector of the GIS from the XRF core scanner-derived geochemistry of a sediment core retrieved from Upernavik Trough, Melville Bay. The elemental signature of material derived from Melville Bay glaciers, Upernavik Isstrom and Rink Isbrae can be inferred from the geology of the bedrocks drained by these major ice streams of the western GIS. Changes in abundance of Fe-rich basaltic material reflect changes in West Greenland Current (WGC) strength. Contributions from Melville Bay glaciers were dominant during the early part of the record as a result of the rapid retreat of this stretch of the NW GIS. Atmospheric warming and strengthened WGC between 7.5 and 5 cal. Kyrs BP promoted contributions from distal southern sources of lithic material to the sedimentation over Upernavik Trough. The Neoglacial shift in climate and ocean circulation led to a general reduction in the delivery of lithic material from western GIS glacier outlets glaciers. The particular geomorphology of the fjord hosting Rink Isbrae as well as the important depth of the Uummannaq Trough likely explain the high relative contribution of this glacier to the lithic sedimentation over Upernavik Trough during the later part of the Holocene despite a weakened WGC.< Réduire
Mots clés en anglais
West Greenland
Holocene
Tidewater glaciers
Climate changes
Ocean circulation
Project ANR
Productivité biologique dans l'Océan Arctique: réponse passée, présente et future aux fluctuations climatiques, et impacts sur les flux de carbone, le réseau trophique et les communautés humaines locales - ANR-14-CE01-0017