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TitreNumerical modelling of seabed disturbance and sediment mobility, with applications to morphodynamics on the storm-dominated Sable Island Bank, Scotian Shelf
TéléchargerTéléchargements
AuteurLi, M Z; Zou, Q; Hannah, C; Perrie, W; Prescott, R; Toulany, B
SourceCommission géologique du Canada, Dossier public 6155, 2009, 1 feuille, https://doi.org/10.4095/247853 (Accès ouvert)
Image
Année2009
ÉditeurRessources naturelles Canada
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/247853
Mediapapier; en ligne; numérique
FormatsJPEG2000; pdf
ProvinceRégion extracotière de l'est
Lat/Long OENS -62.0000 -59.0000 44.5000 43.2500
Sujetsmilieux de marée; marées; courants de marée; distribution des sédiments; transport des sediments; milieu sédimentaire; sedimentation; dynamique sédimentaire; propagation des ondes; courants; levés géophysiques; bathymétrie; géologie marine; sédimentologie
Illustrationslocation maps; images
ProgrammeAléas géologiques et contraintes à la mise en valeur des ressources extracôtières, Géosciences à l'appui de la gestion des océans
Diffusé2009 09 08
Résumé(disponible en anglais seulement)
Waves, tidal currents, wind-driven and circulation currents, and sediment mobility were modelled for one full year over the storm-dominated Sable Island Bank (SIB), Scotian Shelf. The mean shear velocity of tidal current and that of the wind-driven and circulation current are less than 2 cm/s, but the peak mean wave and combined wave-current shear velocities reach 4 and 4.5 cm/s respectively. Comparison between the model-predicted shear velocity and bedload threshold suggests that the circulation and wind-driven currents cause minimum sediment mobility on SIB. Tidal current and waves can each cause sediment mobility at least once a year over 36% and 71% of the bank area respectively, while the combined wave-current shear can cause sediment mobility over 93% of the bank area. Calculated time percentages of sediment mobility caused by various processes indicate that wave or wave-dominant disturbance is most important and occurs over >50% of the bank area, while mixed disturbance is also significant and occurs over ~ 30% of the bank area. Tide or tide-dominant disturbance occurs over only 10% of the bank area. Several parameters are proposed as universal indices for quantifying seabed disturbance and sediment mobility for coastal and shelf environments.This distribution and mobility of various mid-sized bedforms were correlated with the seabed disturbance parameters. Updated bedform distribution was compared with seabed disturbances predictions to define seven bedform zones on SIB.
GEOSCAN ID247853