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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 (>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 |
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| 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 |
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