Consulta: subjectFacets:"Mud"
Registros recuperados: 9
Data/hora: 01/06/2024 09:22:44

Sedimentation on intertidal mudflats in the lower part of macrotidal estuaries: Sedimentation rhythms and their preservation
Provedor de dados: 5
Autores: Deloffre, J; Verney, Romaric; Lafite, R; Lesueur, P; Lesourd, S; Cundy, A.
The objective of this study is to propose an original approach to the analysis of the formation of intertidal rhythmites, their preservation, and the evaluation of sedimentation rates on estuarine mudflats. Three mudflats, one from each of three estuaries, were analysed using a combination of long-term (&gt;a year), high-frequency (1 burst/10 or 20 min), and high-resolution (0.2 cm) altimeter datasets and X-ray images of sediment cores collected during topographic surveys. The results highlight the roles played by sediment supply, hydrodynamics, and morphology of the lower estuaries on the sedimentation rhythms. While the sediment-starved Medway estuary (Kent, UK) remains stable at different time-scales, the annual sedimentation rates on the sheltered...
Tipo: Text
Palavras-chave: Macrotidal estuary; X ray imagery; Altimeter; Rhythmites; Mud; Morphology.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3517.pdf

Modeling mud and sand transfers between a macrotidal estuary and the continental shelf: influence of the sediment-transport parameterization
Provedor de dados: 5
Autores: Diaz, Melanie; Grasso, Florent; Le Hir, Pierre; Sottolichio, Aldo; Caillaud, Matthieu; Thouvenin, Benedicte.
Coastal environments are directly influenced by terrigenous inputs coming from rivers through estuaries. Quantifying the amount of nutrients and contaminants transported by sediments from continental areas to the sea is crucial for marine resources protection. However, the complexity of estuarine dynamics makes it difficult to quantify sediment fluxes from field measurements alone and requires numerical modeling. Thus, using a realistic 3D hydrodynamic and sediment transport model, this study aims at evaluating the influence of model empirical parameters on sediment fluxes and estimating uncertainties on mud and sand transfers at a macrotidal estuary mouth. A sensitivity analysis, considering changes in sediment transport parameters, revealed that the...
Tipo: Text
Palavras-chave: Sensitivity analysis; Sediment fluxes; Numerical modeling; Mud; Sand; Gironde Estuary.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00617/72897/71906.pdf

Rejets urbains. Volet Manche - Atlantique - Site de Morlaix - Etudes sédimentologique et Bathymétrique de l' estuaire de Morlaix
Provedor de dados: 5
Autores: Bassoullet, Philippe; L'Yavanc, Jacky; Guillaud, Jean-francois; Loarer, Ronan; Breton, Marguerite.
In order to increase our knowledge about sediment transport in the bay and maritime part of the River of Morlaix (Finistère), measurernènts have been perforrned on site. This report gives the granulometrical and physical parameters of the sediments as weIl as the hydrodynamics, used for a model of particulate transport in the area. The rnodel and its application will be published later
Tipo: Text
Palavras-chave: Rejet urbain; Sédiment; Granulométrie; Hydrodynamique; Modèle de transport particulaire; Sable; Vase; Estuaire de Morlaix.; Urban wastes; Model; Sediment; Granulometry; Hydrodynamics; Sand; Mud; Sedimentary transport model; Morlaix estuary.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/00345/45658/45293.pdf

Dynamics of sand and mud mixtures: a multiprocess-based modelling strategy
Provedor de dados: 5
Autores: Le Hir, Pierre; Cayocca, Florence; Waeles, Benoit.
Mixed sediments are constituted of cohesive and non-cohesive materials with distinct behaviours that numerical models traditionally manage separately. This paper first introduces a rapid state of the Art in sediment transport modelling in order to point out the specific requirements for process-based models applied to mixed sediments.  Based on a preliminary study by Waeles et al. (2007), which showed the validity of the advection approach to compute fine sand transport, a complete modelling strategy is described: it is applied to the suspended transport of sand and mud mixtures, and accounts for consolidation of mixed sediments. Special care is paid to the realistic representation of the structure and density of sand and mud mixtures, and to the...
Tipo: Text
Palavras-chave: Sediment transport modelling; Mixed sediment; Sand; Mud; Suspension; Consolidation.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00028/13952/12567.pdf

Action des epandages de craie (ou CaCO3) sur les vases des claires et des parcs ostreicoles.
Provedor de dados: 5
Autores: Feuillet, Michelle; Gouleau, Dominique.
Tipo: Text
Palavras-chave: Water quality; Mineralization; Mud; Oyster pond; Chalk spreeding.
Ano: 1977
URL: http://archimer.ifremer.fr/doc/1977/publication-1993.pdf

Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France) - Part 1: Numerical Modeling of Turbidity Maximum Dynamics
Provedor de dados: 5
Autores: Grasso, Florent; Verney, Romaric; Le Hir, Pierre; Thouvenin, Benedicte; Schulz, Elisabeth; Kervella, Youenn; Fard, I. Khojasteh Pour; Lemoine, J. -p.; Dumas, Franck; Garnier, Valerie.
Tidal pumping, baroclinic circulation and vertical mixing are known to be the main mechanisms responsible for the estuarine turbidity maximum (ETM) formation. However, the influence of hydro-meteorological conditions on ETM dynamics is still not properly grasped and requires further investigation to be quantified. Based on a realistic 3-dimensional numerical model of the macrotidal Seine Estuary (France) that accounts for mud and sand transport processes, the objective of this study is to quantify the influence of the main forcing (river flow, tides, waves) on the ETM location and mass changes. As expected, the ETM location is strongly modulated by semidiurnal tidal cycles and fortnightly timescales with a high sensitivity to river flow variations. The ETM...
Tipo: Text
Palavras-chave: Estuary; Mud; Sand; Hydrodynamics; Turbidity maximum; Waves; Measurement; Modeling.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00416/52770/53638.pdf

Nature and rates of fine-sedimentation on a mid-shelf: "La Grande Vasiere" (Bay of Biscay, France)
Provedor de dados: 5
Autores: Dubrulle, C; Jouanneau, J; Lesueur, P; Bourillet, Jean-francois; Weber, O.
The study area, "La Grande Vasiere" (LGV), stretches out on the French Atlantic continental shelf (at ca. 100 m water depth), along 250 km from the Glenan Islands at the north to the southwest of Rochebonne at the south. Box-cores were sampled in this mid-shelf area during four cruises in June 1995, and in April, June and September 2002. They were investigated using sedimentologicat approaches (X-radiographs and grain-size analyses) and radionuclide studies (Pb-210 geochronology and excess Th-234). The main results are: (1) the surficial sediments are generally organized into a decimetrescale fining up sequence which can be the result of extreme storms; (2) an upper mixing layer of 7-20cm reflects an important biological benthic activity and/or the impact...
Tipo: Text
Palavras-chave: Bay of Biscay; Continental shelf; Sedimentation rate; Radionuclides; Fine sediment fraction; Mud.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3539.pdf

Foraminíferos bentónicos de la Bahía de Santa Elena - Ecuador, durante 2006-2007
Provedor de dados: 20
Autores: Gualancañay, E.
Se identificaron doce especies de foraminíferos bentónicos en la bahía de Santa Elena, Ecuador, correspondientes a mayo de 2006 y octubre de 2007. Las especies halladas son típicas de aguas poco profundas entre 4 y 20 metros de profundidad sobre sedimento arenoso y mezcla de arena y limo y son las siguientes: Cibicides aknerianus, Cibicides bertheloti f. boueana, Elphidium articulatum, Nonion pizarrense, Quinqueloculina agglutinans, Quinqueloculina granulosa, Quinqueloculina lamarckiana, Rotalia beccarii, Saccammina calcarea, Textulariella foliacea, Textularia secasensis y Trochammina advena.
Tipo: Journal Contribution
Palavras-chave: Foraminifera; Shallow water; Sand; Mud; Sand; Mud; Http://aims.fao.org/aos/agrovoc/c_6779; Http://aims.fao.org/aos/agrovoc/c_4973.
Ano: 2009
URL: http://hdl.handle.net/1834/3359

Hidden impacts of the Samarco mining waste dam collapse to Brazilian marine fauna - an example from the staurozoans (Cnidaria)
Provedor de dados: 49
Autores: Miranda,Lucília Souza; Marques,Antonio Carlos.
The collapse of the Fundão tailings dam at Mariana (State of Minas Gerais, Brazil) started a huge human tragedy and likely the most serious environmental disaster in recent Brazilian history. The dam had contained waste from processing iron ore from mines owned by Samarco, a joint venture company of the Brazilian Vale S.A. and the Anglo-Australian BHP Billiton Ltd. Following ineffective attempts to contain the disaster, after 16 days the mud flood reached the sea, where its impact is expected to affect thousands of marine fauna and flora species. Here, we provide an example of one of these species, the cnidarian Kishinouyea corbini Larson 1980 (Staurozoa), emblematic because it is extremely rare, poorly studied, and its known distribution overlaps the...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Espírito Santo; Rio Doce; Mud; Staurozoa; Kishinouyea corbini.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000200401