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| Registros recuperados: 27 | |
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| Millot, Claude. |
| Continental shelf dynamics have been observed since 1974 in the Gulf of Lions (NorthWestern Mediterranean Sea), with the principal aim of understanding the sumrner circulation in this region. From satellite infrared data, current meters, thermistor chains, and tidal gauge records, it appears that the major events occurring on the continental shelf take the form of wind-induced mesoscale phenomena. These phenomena, which are connected with strong and transient coastal upwellings, are generated by NorthWesterly winds, the mistral and the tramontane, which are highly transient in speed, with a stable direction and a short lifetime. These specifie features have enabled us to investigate the transient response of the sea on about ten such occasions per typical... |
| Tipo: Text |
Palavras-chave: Upwelling côtier; Plateau continental; Golfe du Lion; Coastal upwelling; Continental shelf; Gulf of Lions. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00122/23335/21159.pdf |
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| Jouet, Gwenael; Hutton, E; Syvitski, J; Berne, Serge. |
| Passive continental margin subsidence is initiated by the synrift mechanical stretching of the lithospheric upper brittle layer and continues during the postrift phase; the thermal cooling and contraction of the upwelled asthenosphere forces the margin to subside in addition to the overloads from sea water and sediments. Therefore, the total subsidence in stretched basins includes fault-controlled initial sinking, thermal subsidence and flexural isostatic compensations. Decoupling and estimating the different components of this subsidence from stratigraphic analysis and restricted geophysical and sedimentological databases remains problematic. In particular, backstripping the sediment layers requires a well-constrained geological framework. A method is... |
| Tipo: Text |
Palavras-chave: Gulf of Lions; Continental shelf; Sedflux; Stratigraphic simulations; Isostasy; Subsidence. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4640.pdf |
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| Mengual, Baptiste; Le Hir, Pierre; Cayocca, Florence; Garlan, T.. |
| Based on experiments, a trawling-induced erosion dynamics was included in a 3D realistic and pre-validated hydro-sedimentary model so as to assess its contribution to the overall regional sediment dynamics in the specific case of the Bay of Biscay continental shelf. The effect of trawling was investigated throughout a 5-year period in terms of horizontal/vertical fluxes and changes in seabed mud content, and compared to the natural variability of sediment fluxes at different spatio-temporal scales. Trawling is shown in the model to significantly contribute to sediment re-suspension, and changes in the seabed at the scale of the shelf. The contribution of trawling to re-suspension is >80% during the high fishing season at many locations on the outer... |
| Tipo: Text |
Palavras-chave: Sediment fluxes; Bottom trawling; Numerical modelling; Bay of Biscay; Continental shelf. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00500/61146/64574.pdf |
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| Redois, F; Debenay, Jp. |
| Two hundred and twenty four benthic foraminiferal species were recognized in the total assemblages of fifty samples collected from the Senegalese continental shelf south of Dakar (down to a depth of 200 m). A factor analysis based on nineteen dominant species shows three main factors. The first two seem to be associated with temperature and its seasonal variations; they are depth-related and determine two main faunal changes. The third factor is substrate-related. The main depth-related species are: i) Cribrononion gerthi, Quinqueloculina akneriana, Quinqueloculina lamarckiana, Cribrolinoides curtus, Elphidium fichtellianum and Textularia sagittula in th coastal zone; ii) Discorbinella bertheloti, Cancris aff. C. sagrum, Textularia truncata, Nonion fabum,... |
| Tipo: Text |
Palavras-chave: Foraminifère actuel; Plateau continental; Atlantique; Sénégal; Recent foraminifer; Continental shelf; Atlantic; Senegal. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43622/43920.pdf |
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| Lazure, Pascal; Jegou, Anne-marie; Kerdreux, Michel. |
| The Bay of Biscay is characterised by large fresh water inputs from two major rivers, the Loire and the Gironde, with a mean discharge of about 900 m(3)/s. To describe the spatial and temporal variability of the Loire and Gironde plumes, continuous salinity measurements were made at 4 locations on French coastal islands over periods lasting at least two years. These islands are located at a distance from the large local gradients linked to local inputs. Whereas sea surface salinity in the centre of the Bay of Biscay is 35.6, salinities at the coast vary between about 35 in summer to occasionally less than 30 in late winter or in spring. Minimum salinities do not occur at the same time along the coast, indicating a strong spatial gradient. Near the Loire... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Continental shelf; River plume; Seasonal variability; Salinity; Hydrology. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3957.pdf |
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| Menesguen, Alain; Dussauze, Morgan; Dumas, Franck; Thouvenin, Benedicte; Garnier, Valerie; Lecornu, Fabrice; Repecaud, Michel. |
| European directives (Water Framework Directive - WFD and Marine Strategy Framework Directive - MSFD) require a regular survey of several descriptors of the Environmental Status of coastal waters of the North-east Atlantic Ocean. Especially for the MSFD, which may concern large continental shelf areas where measurements are scarce, realistic ecological models can help assessing the Environmental Status. The ECO-MARS3D model of the pelagic ecosystem of the Bay of Biscay and English Channel continental shelf (NE Atlantic) has been developed for these applied purposes and validated against various types of historic data. This first paper deals with the basic biogeochemical version, which contains inorganic nutrients (NH4, NO3, PO4, Si(OH)4), three... |
| Tipo: Text |
Palavras-chave: Ecological 3D model; Continental shelf; Bay of Biscay and English Channel; Surface chlorophyll; Dissolved oxygen; MSFD. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58098/60510.pdf |
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| Jansen, Jan; Dunstan, Piers K.; Hill, Nicole A.; Koubbi, Philippe; Melbourne‐thomas, Jessica; Causse, Romain; Johnson, Craig R.. |
| Characterising the spatial distribution and variation of species communities and validating these characteristics with data from the field are key elements for an ecosystem‐based approach to management. However, models of species distributions that yield community structure are usually not linked to models of community dynamics, constraining understanding and management of the ecosystem, particularly in data‐poor regions. Here we use a qualitative network model to predict changes in Antarctic benthic community structure between major marine habitats characterised largely by seafloor depth and slope, and use multivariate mixture models of species distributions to validate the community dynamics. Further, we then assess how future increases in primary... |
| Tipo: Text |
Palavras-chave: Deep‐sea; Ecosystem structure; Ecosystem dynamic; Southern Ocean; Antarctica; Continental shelf; Upper slope; Species archetype model; Qualitative network model; Spatial model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71143/69460.pdf |
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| Lafosse, M.; Gorini, C.; Le Roy, P.; Alonso, B.; D'Acremont, E.; Ercilla, G.; Rabineau, Marina; Vazquez, J. T.; Rabaute, A.; Ammar, A.. |
| In active basins, tectonics can segment the continental shelf and control its stratigraphic architecture and physiography. Segmentation can explain the local evolution and morphology of the continental shelf because of sea-level variations, local tectonic segmentation and hydrodynamic processes. Here we investigate the tectonically active Morocco continental margin (southern Alboran Sea) using high-resolution seismic profiles and multibeam bathymetric data. The active faults bounding the transtensive Nekor basin triggered the segmentation of the shelf into three sectors showing different subsidence rates: a western sector corresponding to an extensive fault relay, a central sector corresponding to the subsiding Al-Hoceima Bay and an eastern sector... |
| Tipo: Text |
Palavras-chave: Seismic stratigraphy; Active tectonic; Pleistocene; Continental shelf; Swath bathymetry; Geomorphology; Western Mediterranean. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56232/57812.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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| Reynaud, Jean-yves; Lauriat-rage, Agnès; Tessier, Bernadette; Neraudeau, Didier; Braccini, Eric; Carriol, René-pierre; Clet-pellerin, Martine; Moullade, Michel; Lericolais, Gilles. |
| Macro- and micro-faunas are reported from six gravity cores collected at a mean depth of 150 m in the surficial deposits of the Kaiser sand bank in the Southern Western Channel Approaches. These are bivalves (mainly), gastropods, echinids, crustaceans and foraminifers. These fauna present a very rich association of numerous, well preserved species from various ecological settings. Such an association is commonly reported from the continental shelf of the last transgressive cycle. In addition, the sediment comprises two imported faunal associations. The first one corresponds to thanatocaenoses of Pliocene/lowermost Pleistocene and Weichselian age, reworked respectively from the underlying celtic incised valley fills and the Celtic Sand Banks. The absence of... |
| Tipo: Text |
Palavras-chave: Continental shelf; Thanatofauna; Sea level; Reworking; Transport. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00146/25682/23843.pdf |
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| Guillaud, Jean-francois; Aminot, Alain; Delmas, Daniel; Gohin, Francis; Lunven, Michel; Labry, Claire; Herbland, Alain. |
| Seasonal variations in nutrient inputs are described for the main rivers (Loire and Vilaine) flowing into the northern Bay of Biscay. The river plumes are high in N/P ratio in late winter and spring, but not in the inner plume during the summer. Conservative behavior results in most nutrients entering the estuary and eventually reaching the coastal zone. Temporal and spatial aspects of phytoplankton growth and nutrient uptake in the northern Bay of Biscay distinguish the central area of salinity 34 from the plume area. The first diatom bloom appears offshore in late winter, at the edge of the river plumes, taking advantage of haline stratification and anticyclonic "weather windows." In spring, when the central area of the northern shelf is... |
| Tipo: Text |
Palavras-chave: Northern Bay of Biscay; Phytoplankton; Continental shelf; Riverine inputs; Nutrients. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2354.pdf |
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| Dupré, Stephanie; Loubrieu, Benoit; Pierre, C.; Scalabrin, Carla; Guerin, Charline; Ehrhold, Axel; Ogor, Andre; Gautier, Emeric; Ruffine, Livio; Biville, Romain; Saout, Johan; Breton, C; Floodpage, J.; Lescanne, M.. |
| A few thousand (2612) seeps are releasing microbial methane bubbles from the seafloor at the Aquitaine Shelf edge (Bay of Biscay) at shallow water depths (140‐220 m). This methane contributes to the formation of meter‐scale subcircular carbonate structures, which are (sub‐)outcropping over 375 km2. Based on in situ flow rate measurements and acoustic data, and assuming steady and continuous fluxes over time, the methane entering the water column is estimated to 144 Mg/yr. Microbial methane circulation has been on‐going for at least a few thousand years. This discovery highlights the importance of microbial methane generation, disconnected from deep thermogenic sources and gas hydrates, at continental shelves. The shelf edge may be viewed as a focus area... |
| Tipo: Text |
Palavras-chave: Microbial methane; Continental shelf; Fluid emissions; High‐resolution acoustics; Aquitaine Margin; Methane‐derived authigenic carbonates. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/72982/72057.pdf |
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| Registros recuperados: 27 | |
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