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TitleA modeling study of the impact of major storms on seabed shear stress and sediment transport on the Grand Banks of Newfoundland
AuthorLi, M Z; Wu, Y; Han, G; Prescott, R H; Tang, C C L
Sourcevol. 122, no. 5, 2017 p. 4183-4216, https://doi.org/10.1002/2016JC012215 (Open Access)
Year2017
Alt SeriesEarth Sciences Sector, Contribution Series 20160176
PublisherWiley-Blackwell
Documentserial
Lang.English
Mediaon-line; digital
File formatpdf (Adobe® Reader®); html
ProvinceNewfoundland and Labrador; Eastern offshore region
NTS1; 2C; 2E; 2F; 10/NE; 11A; 11B; 11G; 11H; 11I; 11J; 11L; 11M; 11N
AreaGrand Banks of Newfoundland; St. Pierre Bank; Flemish Cap; Avalon Channel; Grand Bank; Whale Bank; Green Bank; Southeast Shoal
Lat/Long WENS -60.0000 -44.0000 50.0000 42.0000
Subjectsmarine geology; surficial geology/geomorphology; Nature and Environment; Science and Technology; continental margins; continental shelf; marine sediments; sands; shear stress; sediment transport; climate; meteorology; storms; oceanography; currents; bottom currents; tidal currents; computer simulations; modelling; bathymetry; erosion; accretion; grain size analyses; sedimentation; Hibernia; Newfoundland Shelf; seabed shear stress; waves; water depths; storm-induced currents; pebbles; sediment transport potential; wave heights; 3-D modelling
Illustrationslocation maps; geoscientific sketch maps; tables; time series; plots
ProgramMarine Geohazards, Public Safety Geoscience
Released2017 05 22
AbstractWaves, current and sediment transport processes in major storms on the Grand Banks of Newfoundland were simulated using integrated wave, three-dimensional tidal and ocean currents, and combined-flow sediment transport models. While the tidal and circulation currents are low and cause little sediment transport, storm-induced waves and currents enhance bed shear velocity by more than 5 times and cause wide occurrence of transport of medium sand over the entire Grand Banks. The storm impact on shear stress and transport strongly depends on water depths and the greatest impact occurs over the bathymetric highs on southeastern Grand Bank where the maximum shear velocity reaches 15 cm s-1 and the maximum transport rates are >5 kg m-1 s-1. The direction of sediment transport rotates clockwise progressively through nearly 360° during the passage of a storm. Although peak transport typically occurs on central and southeastern Grand Bank with a southeasterly direction, the magnitude, direction and timing of peak transport show strong spatial and temporal variability. The variability of the peak transport largely depends on the timing and relative intensity of the waves and the total bottom currents which in turn depends on the addition of the storm-induced and tidal currents. The calculation of the maximum transport potential suggests that sediments as coarse as small pebbles are mobile in depths < 80 m under 1:1 year storms and that medium sand transport occurs in depths as deep as 200 m during major storms. Sediment transport modelling results corroborate the observed sediment erosion and accretion patterns.
Summary(Plain Language Summary, not published)
Severe winter storms generate huge waves and strong bottom currents that greatly impact the seabed on the Grand Banks of Newfoundland. Seabed impact and sediment transport processes during major storms on the Grand Banks were studied using numerical modelling method. While the tidal and circulation currents are low and cause little sediment transport, storm-induced waves and currents enhance bed shear velocity by more than 5 times and cause wide occurrence of sediment transport over the entire Grand Banks. The storm impact on shear stress and sediment transport is the greatest over the shallow waters on southeastern Grand Bank where the maximum shear velocity reaches 15 cm s-1 and the maximum transport rates are >5 kg m-1 s-1. The direction of sediment transport rotates clockwise progressively during the passage of a storm. Sediments as coarse as small pebbles are mobile in depths < 80 m under 1-year storms and medium sand transport occurs in depths as deep as 200 m during major storms.
GEOSCAN ID299241