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| Registros recuperados: 34 | |
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| Meule, S; Pinazo, C; Degiovanni, C; Barusseau, Jp; Libes, M. |
| In marine coastal environments, storms have a major morphological impact on sand beaches. This study, part of the French Programme National d'Environnement Cotier, consisted in developing and applying hydrodynamic and sedimentary models to simulate the major processes that modify sand beaches. In order to study sediment dynamics, we developed three models to simulate waves, currents and sediment transport associated with a storm event. The wave model was a Mild Slope Equation model based on the parabolic approximation of the refraction-diffraction equation of Berkhoff. The hydrodynamic model was obtained by the depth-average of Navier Stockes' equations forced by the terms of radiation stresses induced by waves. The sedimentary model SEDSIM developed by... |
| Tipo: Text |
Palavras-chave: Modification de la plage; Modèles numériques; Transport sédimentaire; Tempête; Courants induits par la houle; Beach modification; Numerical models; Sediment transport; Storm; Wave-induced current. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43339/42887.pdf |
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| Guillou, Nicolas; Rivier, Aurelie; Chapalain, Georges; Gohin, Francis. |
| Numerous ecological problems of continental shelf ecosystems require a refined knowledge of the evolution of suspended sediment concentrations (SSC). The present investigation focuses on the spatial and temporal variabilities of near-surface SSC in coastal waters of the English Channel (western Europe) by exploiting numerical predictions from the Regional Ocean Modeling System ROMS. Extending previous investigations of ROMS performances in the Channel, this analysis refines, with increased spatial and temporal resolutions, the characterization of near-surface SSC patterns revealing areas where concentrations are highly correlated with evolutions of tides and waves. Significant tidal modulations of near-surface concentrations are thus found in the eastern... |
| Tipo: Text |
Palavras-chave: Sediment transport; Numerical modeling; Satellite; ROMS; MERIS; MODIS. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00345/45607/45227.pdf |
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| Drago, T; Oliveira, A; Magalhaes, F; Cascalho, J; Jouanneau, Jm; Vitorino, Joao. |
| On the basis of sedimentological and oceanographical data, a transport scheme for fine-grained material is proposed in order to explain the location of a muddy deposit present in the northern Portuguese continental shelf, north-west off the Douro River mouth. This mid-shelf deposit is recent, active and its main source is apparently the Douro River. The sediment supply can be related with the oceanographic conditions in winter regime, characterised by a poleward along shelf current with a bottom westward component, as a consequence of a south-west wind. The resulting fine sediment transport, essentially made in the bottom nepheloid layer is believed to have a north-west direction. |
| Tipo: Text |
Palavras-chave: Plateau continental portugais; Sédiment fin; Biotite; Transport de sédiments; Hydrologie hivernale; Portuguese shelf; Fine sediments; Biotite; Sediment transport; Winter regime. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00326/43681/43193.pdf |
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| Dufois, Francois; Garreau, Pierre; Le Hir, Pierre; Forget, P. |
| Simulations of both currents and waves were performed throughout the year 2001 to assess the relative contribution of each to their overall erosive potential on the Gulf of Lions shelf. Statistical analysis of bottom shear stress (BSS) was compared to sediment grain-size distribution on the bottom. The hydrodynamic features of the bottom layer coincide with the distribution of surficial sediments, and three areas with different hydro-sedimentary characteristics were revealed. (i) The sandy inner shelf ( < 30 m) area is a high-energy-wave dominated area but may be subjected to intense current-induced BSS during on-shore winds along the coast and during continental winds mainly in the up-welling cells. (ii) The middle shelf (30-100 m) is a low-energy... |
| Tipo: Text |
Palavras-chave: Gulf of Lions; 3D modelling; Bottom shear stress; Sediment transport. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6305.pdf |
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| Bertin, Xavier; De Bakker, Anouk; Van Dongeren, Ap; Coco, Giovanni; Andre, Gael; Ardhuin, Fabrice; Bonneton, Philippe; Bouchette, Frederic; Castelle, Bruno; Crawford, Wayne C.; Davidson, Mark; Deen, Martha; Dodet, Guillaume; Guerin, Thomas; Inch, Kris; Leckler, Fabien; Mccall, Robert; Muller, Heloise; Olabarrieta, Maitane; Roelvink, Dano; Ruessink, Gerben; Sous, Damien; Stutzmann, Eleonore; Tissier, Marion. |
| Infragravity (hereafter IG) waves are surface ocean waves with frequencies below those of wind-generated "short waves" (typically be- low 0.04 Hz). Here we focus on the most common type of IG waves, those induced by the presence of groups in incident short waves. Three related mechanisms explain their generation: (1) the development, shoaling and release of waves bound to the short-wave group envelopes (2) the modulation by these envelopes of the location where short waves break, and (3) the merging of bores (breaking wave front, resembling to a hydraulic jump) inside the surfzone. When reaching shallow water (O(1-10 m)), IG waves can transfer part of their energy back to higher frequencies, a process which is highly dependent on beach slope. On gently... |
| Tipo: Text |
Palavras-chave: Infragravity waves; Bound wave; Dissipation; Reflection; Sediment transport; Barrier breaching; Seiche; Earth hum. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00417/52876/53800.pdf |
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| Payo-payo, Marta; Silva Jacinto, Ricardo; Lastras, G.; Rabineau, Marina; Puig, P.; Martin, J.; Canals, M.; Sultan, Nabil. |
| Bottom trawling leads to recurrent sediment resuspension events over fishing grounds. Recent studies have shown how bottom trawling can drive seascape reshaping at large spatial scales and enhance sediment transport in submarine canyons, which subsequently impacts deep-sea ecosystems. Present knowledge on the transfer and accumulation of sediment flows triggered by bottom trawling is based on localized and infrequent measurements whilst a more complete picture of the process is needed. The present work focuses on the modeling of sediment transport and accumulation resulting from trawling activities in La Fonera submarine canyon, northwestern Mediterranean Sea, thus contributing to an improved assessment of trawling impacts. Based on mooring data within a... |
| Tipo: Text |
Palavras-chave: Bottom trawling; Inverse model; Modeling; Sediment transport; Submarine canyon; Turbidity currents. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00374/48549/48862.pdf |
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| Mazieres, Alais; Gillet, Herve; Castelle, Bruno; Mulder, Thierry; Guyot, Corentin; Garlan, Thierry; Mallet, Cyril. |
| In this study, the Capbreton canyon head, just off the coast, is investigated using high-resolution multibeam bathymetry datasets, sediment samples and numerical modeling. The HR bathymetry analysis reveals a morphological connection between the longshore trough and the head of the canyon. The analysis of recent sediment samples shows a clear correlation between the sediment of the canyon head and that of the nearshore. Hydrodynamic modeling (a coupled wave-flow model) shows that for high-energy waves, the rotational nature of surf-zone circulation reverses and wave-induced currents have the potential to transport large quantities of nearshore sands toward the canyon head. All these arguments support the assumption that the canyon head captures a part of... |
| Tipo: Text |
Palavras-chave: Longshore drift; Submarine canyon; Capbreton; Hydrodynamic modeling; Sediment transport. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00180/29118/27524.pdf |
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| Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, Cecile; Froidefond, Jean-marie; Andrefouet, Serge; Munoz-caravaca, Alain. |
| Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba), and sediment-rich waters in the Laucala Bay (Fiji). In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at... |
| Tipo: Text |
Palavras-chave: Ocean color; Remote sensing; Sediment transport; Suspended matter; Turbidity; New Caledonia; Cuba; Fiji. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00203/31417/29808.pdf |
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| Orvain, Francis. |
| Flume experiments were designed to study how sediment erodibility was modified by the facultative suspension-feeder Scrobicularia plana living at different densities in sediment beds of various degrees of compaction. Two separate erosion phases were identified from the resuspension kinetics: (1) erosion of an unconsolidated surficial layer (i.e. fluff layer) and (2) the subsequent bed erosion. S. plana were found to influence both erosion phases: (1) erosion rates of the fluff layer were controlled by bioturbation activities, the extents of which were influenced by bivalve density and the degree of compaction of the sediments, and (2) critical thresholds of the subsequent bed erosion decreased as clam density increased, likely due to depressions in the... |
| Tipo: Text |
Palavras-chave: Resuspension; Model; Functional groups; Sediment transport; Bioturbation; Scrobicularia plana; Intertidal mudflat. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3776.pdf |
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| Registros recuperados: 34 | |
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