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TitreControls on the formation of turbidity current channels associated with marine-terminating glaciers and ice sheets
AuteurPope, E L; Normandeau, A; Ó Cofaigh, C; Stokes, C R; Talling, P J
SourceMarine Geology vol. 415, 10595, 2019 p. 1-21, https://doi.org/10.1016/j.margeo.2019.05.010 (Accès ouvert)
Année2019
Séries alt.Ressources naturelles Canada, Contribution externe 20180400
ÉditeurElsevier BV
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.margeo.2019.05.010
Mediapapier; en ligne; numérique
Formatspdf (Adobe® Reader®); html
Lat/Long OENS -76.0000 -20.0000 84.0000 59.0000
Sujetscourants de turbidite; caractéristiques sous-marines; chenaux; sédiments marins; transport des sediments; dispersion des sédiments; volumes de sediment; glaciers; nappes glaciaires; carbone; interprétations géophysiques; bathymétrie; marges continentales; plate-forme continentale; fjords; milieu côtièr; marges glaciaires; écoulement glaciaire; dépôts glaciaires; moraines; télédétection; imagerie par satellite; milieu hydrologique; réseaux hydrographiques; eaux de ruissellement; systèmes d'écoulement; débit de sedimentation; morphologie; Calotte glaciaire du Groenland; eau douce; altitude; géologie marine; géologie des dépôts meubles/géomorphologie; hydrogéologie; géophysique; Nature et environnement
Illustrationslocation maps; geoscientific sketch maps; tables; satellite images; plots; schematic representations
ProgrammeGéo-risques marins, Géoscience pour la sécurité publique
Diffusé2019 06 04
Résumé(disponible en anglais seulement)
Submarine channels, and the sediment density flows which form them, act as conduits for the transport of sediment, macro-nutrients, fresher water and organic matter from the coast to the deep sea. These systems are therefore significant pathways for global sediment and carbon cycles. However, the conditions that permit or preclude submarine channel formation are poorly understood, especially when in association with marine-terminating glaciers. Here, using swath-bathymetric data from the inner shelf and fjords of northwest and southeast Greenland, we provide the first paper to analyse the controls on the formation of submarine channels offshore of numerous marine-terminating glaciers. These data reveal 37 submarine channels: 11 offshore of northwest Greenland and 26 offshore of southeast Greenland. The presence of channels is nearly always associated with: (1) a stable glacier front, as indicated by the association with either a moraine or grounding-zone wedge; and (2), a consistent seaward sloping gradient. In northwest Greenland, turbidity current channels are also more likely to be associated with larger glacier catchments with higher ice and meltwater fluxes which provide higher volumes of sediment delivery. However, the factors controlling the presence of channels in northwest and southeast Greenland are different, which suggest some complexity about predicting the occurrence of turbidity currents in glacier-influenced settings. Future work on tidewater glacier sediment delivery rates by different subglacial processes, and the role of grain size and catchment/regional geology is required to address uncertainties regarding the controls on channel formation.
Résumé(Résumé en langage clair et simple, non publié et disponible en anglais seulement)
Submarine channels, and the turbidity currents which form and navigate them, act as conduits for the transport of sediment, macro-nutrients, fresher water and organic matter from the coast to the deep sea. The exact conditions that permit or prevent submarine channel formation are poorly understood, especially when in association with marine-terminating glaciers. Here, using swath-bathymetric data from the inner shelf and fjords of Northwest and Southeast Greenland, we analyse the controls on the formation of submarine channels offshore marine-terminating glaciers.
GEOSCAN ID313660