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TitreNumerical model predictions of seabed disturbance, sediment mobility and sediment transport in the Bay of Fundy, Canada
AuteurLi, M Z; Hannah, C; Perrie, W; Tang, C; Prescott, R
Source27th International association of sedimentologists meeting of sedimentology, abstracts volume; 2009, 1 pages
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090208
Réunion27th International Association of Sedimentologists Meeting of Sedimentology; Alghero; IT; Septembre 20-23, 2009
ProvinceRégion extracotière de l'est
Lat/Long OENS-67.5000 -63.5000 46.0000 44.0000
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
ProgrammeGéoscience en mer, Énergie renouvelable offshore
Résumé(disponible en anglais seulement)
The Bay of Fundy located on the east coast of Canada has been of great economic, ecological and scientific significance because of its world-renowned tides, unique seabed geology, and diverse ecosystems. Busy shipping lanes, numerous ports and coastal infrastructures, significant fisheries and aquaculture industry, and various sanctuaries, reserves, and marine protected areas create various conflicts in the use of the waters and seabed in the bay. There has been a renewed interest in developing the huge tidal energy in the Bay of Fundy in recent years. Demonstration project has already began and commercial developments are also on the horizon. All these economical and environmental issues demand sound knowledge of the nearbed hydrodynamic and sedimentary processes for the region.
Waves, tidal currents, and wind-driven and circulation currents were predicted from oceanographic models. These wave and current outputs were coupled with observed grain size and high-resolution bathymetry in a sediment transport model (SEDTRANS) to predict the seabed disturbance, sediment mobility, and sediment transport pattern in the Bay of Fundy. Mean tidal current is the highest in the upper bay (> 1.2 m/s), reduced to moderate in the central and southeastern region (0.5 - 0.8 m/s) and decreased further (0.2 - 0.5 m/s) in the southwest region and the outer bay. Mean wave height, in contrast, is the greatest in the outer bay (~ 1.3 m) and gradually decreases to the northeast in the central and upper bay (< 0.5 m). Ocean circulation currents on average are predominantly less than 0.3 m/s. Maximum mean shear velocity on the seafloor due to all current and wave processes reaches about 5 cm/s and is predominantly due to tidal current. Comparison between the model-predicted shear velocity from various processes and the threshold for bedload transport suggests that sediment mobility caused by waves is restricted to small coastal areas and is less than 5% of the time. Sediment mobilization by tidal current occurs nearly over the entire Bay of Fundy with maximum time percent reaching 80-90% of the time. Accordingly the seabed disturbance regime in the Bay of Fundy is classified as tidedominant. Sediment transport rate and direction in a tidal cycle and during selected storms will also be analysed to demonstrate the regional sediment transport patterns for tide-only and storm conditions.