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Dupont, Jp; Collins, Mb; Lafite, R; Nash, L; Huault, Mf; Shimwell, Sj; Chaddock, S; Brunet, C; Wartel, M; Lamboy, M. |
During a survey at six stations in the Dover Strait, from July 1990 to November 1991, water samples were collected to measure : suspended sediment load and its organic content; particle characteristics; photosynthesis pigments; and heavy metals. In this contribution, particle measurements are interpreted in terms of hydrodynamical effects and seasonal evolution. Multi-modal grain size spectra are indicative of depth and cross-sectional variations, from die coastline to the central waters. Tidal variations, biological productivity and wind effects can be identified. Suspended particulate matter (SPM) components (determined using SEM, when combined with size spectra) illustrate hydrodynamical, geomorphological and biological effects on the composition of the... |
Tipo: Text |
Palavras-chave: SUSPENDED MATTER; DIATOMS; DOVER STRAIT; ENGLISH CHANNEL. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00099/21073/18698.pdf |
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Douez, C; Statham, P; Auger, Y; Choisy, P; Deram, L; Dupont, Jp; Fischer, Jc; Puskaric, E; Wartel, M. |
Within the framework of the European Fluxmanche programme, 92 samplings of suspended particulate matter were collected during eight cruises through the Dover Strait. The mean concentrations obtained for Al (44.3 mg/g), Fe (27.4 mg/g) and Ca (110 mg/g) are comparable to those obtained by Nolting and Eisma in January 1980. However, the concentrations of Mn (0.585 mg/g) Ti (3.14 mg/g) and V (0.225 mg/g) are twice as large. An important gradient of concentration is observed between the coastal and offshore waters, reflecting coastal erosion and human activities. Detailed examination of the contents of the major elements indicates that these remain practically constant in the particulate matter during a tidal cycle. On the other hand, the concentrations of... |
Tipo: Text |
Palavras-chave: SUSPENDED MATTER; TRACE-METAL; DOVER STRAIT; MANGANESE; SEA WATER. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21141/18761.pdf |
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Bentley, D; Lafite, R; Morley, Nh; James, R; Statham, Pj; Guary, Jc. |
As part of the MAST I-FluxManche initiative, a monthly (September 1990 to November 1991) sampling programme has been carried out in the Dover Strait. Samples were taken (weather permitting) at two depths at each of six standard stations between Folkestone and Cap Gris-Nez. Data from all surveys, in conjunction with estimates of water movement derived from hydrodynamic numerical model, have been used to calculate fluxes of nutrients between the Channel and the North Sea. Results demonstrate that although nutrient concentrations are lower in the central channel-waters than in the coastal zone, the dissolved nutrient flux to the North Sea is mom important for stations of the central part of the Dover Strait as water. Current concern about possible increases... |
Tipo: Text |
Palavras-chave: NUTRIENTS; FLUXES; DOVER STRAIT. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21124/18744.pdf |
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Chapalain, G; Smaoui, H; Lepretre, A; Nguyen, Kd; Ouahsine, A; Tessier, B. |
The present paper deals with the modelling of hydro-sedimentary processes in the coastal area near Cape Gris-Nez and Cape Blanc-Nez (Dover Strait). The modelling procedure consists in coupling different hydro-sedimentary process models with a high spatial resolution two-dimensional tidal flow model (Nguyen and Ouahsine, 1992). The sediment transport models used include two semi-empirical models based on a dimensionless analysis and energetic concepts (Ackers and White, 1973; Engelund and Hansen, 1967), and a more heuristic cu (concentration times velocity) model (van Rijn, 1984 a; b). All these models are applied to predict instantaneous and tidally-integrated sediment transports in the area under investigation. |
Tipo: Text |
Palavras-chave: DOVER STRAIT; TIDAL CURRENTS; COASTAL SEDIMENTS; HYDRO-SEDIMENTARY PROCESSES; MODELING. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21140/18760.pdf |
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Grochowski, Ntl; Collins, Mb; Boxall, Sr; Salomon, Jc; Breton, M; Lafite, R. |
Sand transport pathways are predicted, by combining outputs from an hydrodynamic numerical model with empirical sediment transport formulae. Tidal simulations, combined with various wind conditions, are compared with patterns presented in the literature. Results show that tides determine the long-term transport pattern in the area; this consists mainly of an ebb-dominated (North Sea towards Channel) mid-Strait region and flood-dominated pathways along the coastlines, which narrow towards the (Dover) Strait. Localised transport paths are identified; these are believed to be responsible partially for the presence of large sandbanks. Superimposed SW and NE wind activity overwhelms the tidally-induced pattern; this occurs infrequently and long-term pattern is... |
Tipo: Text |
Palavras-chave: ENGLISH CHANNEL; DOVER STRAIT; SEDIMENT DYNAMICS; MODELING; SANDBANKS. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00099/21075/18700.pdf |
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Prandle, D. |
Contaminants from the Channel flow through the Dover Strait into the North Sea where they represent a significant fraction of the enhanced concentrations observed along the continental coast. Despite numerous previous investigations, the magnitude of this net flow and its dependency on various forcing factors remain uncertain. The new UK H.F. Radar system, OSCR (Ocean Surface Current Radar) developed for measuring nearshore surface currents offers a clear opportunity of establishing the magnitude and nature of this flow. Starting in July 1990, H.F. Radar observations were made in the Dover Strait for five months from the French coast overlapping (for two months) with five months from the English coast. These measurements involved fully-automised monitoring... |
Tipo: Text |
Palavras-chave: DOVER STRAIT; HF RADAR; ACOUSTIC DOPPLER; CURRENT PROFILER; TIDAL FLUX. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00099/21070/18695.pdf |
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