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Registros recuperados: 16 | |
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Carbajal, N; Backhaus, Jo. |
With the application of a two-dimensional nonlinear hydrodynamical-numerical semi-implicit model, the principal tides M(2), S(2), K(2), N(2), K(1), P(1) and O(1) were studied. Energy budgets of the semi-diurnal M(2) and S(2) were calculated separately. The linear sum of these budgets was compared with the tidal energy budget obtained when these two tidal constituents interact. Since a quadratic form for the bottom friction was used, remarkable differences were found. The results show that in the area of the Colorado River delta, the dissipation of tidal energy is very strong. Intense tidal currents were observed in the same region and over the Salsipuedes Sill. Energy budgets calculated for forcing waves of different periods, but of the same amplitude,... |
Tipo: Text |
Palavras-chave: Modèle numérique; Marée; Courant résiduel; Bilan énergétique; Seiche; Numerical modelling; Tide; Residual flow; Energy budget; Seiche. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43666/43204.pdf |
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Miramontes, Elda; Jouet, Gwenael; Thereau, Estelle; Bruno, Miguel; Penven, Pierrick; Guerin, Charline; Le Roy, Pascal; Droz, Laurence; Jorry, Stephan; Hernández‐molina, F. Javier; Thiéblemont, Antoine; Silva Jacinto, Ricardo; Cattaneo, Antonio. |
Evidences of sedimentation affected by oceanic circulation, such as nepheloid layers and contourites are often observed along continental slopes. However, the oceanographic processes controlling sedimentation along continental margins remain poorly understood. Multibeam bathymetry and high‐resolution seismic reflection data revealed a contourite depositional system in the Mozambican upper continental slope composed of a contourite terrace (a surface with a gentle seaward slope dominated by erosion) and a plastered drift (a convex‐shape sedimentary deposit). A continuous alongslope channel and a field of sand dunes (mainly migrating upslope), formed during Holocene, were identified in the contourite terrace at the present seafloor. Seismic reflection data... |
Tipo: Text |
Palavras-chave: Contourite; Sediment drift; Bedform; Sedimentary processes; Tide; Internal solitary waves; Bottom currents. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00605/71730/70205.pdf |
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Baltzer, Agnes; Reynaud, Marine; Ehrhold, Axel; Fournier, Jerome; Cordier, Celine; Clouet, Helene. |
About a decade ago, a large field of pockmarks, covering an overall area of 36 km(2) was discovered in water depths of < 30m in the central part of the Bay of Concarneau (Southern Brittany, France). This field, composed of features from 5 m to 35 m in diameter and < 1 m in depth, is characterized by unusual high densities of pockmarks, up to 5840 per square kilometre. Geophysical data correlated with sedimentary samples acquired in 2005 and 2009 show that pockmarks and their immediate surroundings are associated with dense tubes benches cover, built by a filter-feeding amphipod: Haploops nirae, forming original benthic communities. Two complementary surveys were carried out in April 2011 (Pock and Ploops) and April 2014 (Pock and Tide), on the... |
Tipo: Text |
Palavras-chave: Géophysique; Marée; Failles; Gaz; Geophysics; Pockmarks; Tide; Turbidity; Gas; Chimneys pipes; Concarneau. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52107/52938.pdf |
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Martinez, A; Perez, E; Bruno, M. |
Analysis of water level and current meter series from different locations on the island shelf of Gran Canaria reveals strong variations in tidal properties. Semidiurnal sea level amplitudes agree with the results obtained from global tidal models for this region only on the northern coast of the island, while they decrease towards the southwest (10 cm difference for the M-2 constituent). Semidiurnal currents present maxima at the southeastern and northwestern extremities of the island (30-40 cm s(-1) for M-2) and minima in the north-northeast and southwest (3-6 cm s(-1) for M-2), showing simultaneous strong changes in the phase. Diurnal levels and currents display smaller variations than the semidiurnal band. The behaviour of semidiurnal constituents is... |
Tipo: Text |
Palavras-chave: Marée; Courant de marée; Île; Modélisation numérique; Îles Canaries; Tide; Tidal current; Island; Numerical modelling; Canary Islands. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43625/43258.pdf |
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Idier, Deborah; Paris, Francois; Le Cozannet, Goneri; Boulahya, Faiza; Dumas, Franck. |
Sea-level rise (SLR) can modify not only total water levels, but also tidal dynamics. Several studies have investigated the effects of SLR on the tides of the western European continental shelf (mainly the M2 component). We further investigate this issue using a modelling-based approach, considering uniform SLR scenarios from −0.25 m to +10 m above present-day sea level. Assuming that coastal defenses are constructed along present-day shorelines, the patterns of change in high tide levels (annual maximum water level) are spatially similar, regardless of the magnitude of sea-level rise (i.e., the sign of the change remains the same, regardless of the SLR scenario) over most of the area (70%). Notable increases in high tide levels occur especially in the... |
Tipo: Text |
Palavras-chave: Tide; Sea-level rise; Tidal component; Climate change; European Shelf; Resonance. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00367/47859/47842.pdf |
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Bailly Du Bois, P; Dumas, Franck; Morillon, M; Furgerot, L; Voiseux, C; Poizot, E; Mear, Y; Bennis, Anne-claire. |
This study presents an overview of the main hydrodynamic features of the Alderney Race strait based on in-situ measurements and 2D hydrodynamic model simulations. The strait encompasses a large amplitude of tidal properties (tidal range and tidal wave propagation) and particularly strong currents exceeding 5 m.s-1 with associated counter currents and gyres. Variations in depth, sea bottom roughness, coastal topography and current orientation around the La Hague Cape provide access to a large variety of original hydrodynamic regimes. Some are revealed as locations with a 0.4 m drop in the mean sea level associated with strong average currents. A resonance effect associated with the offshore currents can also be observed close to the coasts. The "St Martin... |
Tipo: Text |
Palavras-chave: Alderney Race; La Hague Cape; Current; Tide; Hydrodynamics; Model. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75286/75639.pdf |
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Bao, Xw; Gao, Gp; Yan, J. |
With the fine horizontal (5' x 5') and vertical (15 levels) grids, a three-dimensional model, imbedded a closure turbulence sub-model, was used to calculate the barotropic tides and tidal currents in the Bohai Sea, Yellow Sea, and East China Sea. The computational results are in good agreement with the observed M2, S2, K1 and O1 tides in the domain. Comparison with fifty tide gauges showed that the averaged absolute differences between the simulated and observed amplitudes are only 3.95, 2.96, 2.5 and 1.78 cm for the M2, S2, K1 and O1 tidal waves, respectively. The averaged phase-lag differences of the four tides are 6.88, 6.96, 5.96 and 6.16 degrees. The model reproduces well the tidal charts and this characteristic is discussed in detail. Comparison with... |
Tipo: Text |
Palavras-chave: Modèle 3D; Marée et courants de marée; Mer de Chine; 3D model; Tide; East China Sea. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43360/42855.pdf |
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Guillou, Nicolas; Rivier, Aurelie; Gohin, Francis; Chapalain, Georges. |
The present study investigates the performances of the three-dimensional multicomponent hydro-sedimentary model ROMS (Regional Ocean Modeling System) to predict near-surface suspended sediment concentrations (SSC) in the English Channel (western Europe). Predictions are assessed against satellite-retrieved observations from raw MODIS and MERIS images for the year 2008 characterized by the highest availability of cloud-free data. Focus is put on improvements obtained with: (1) SSC inputs at the open boundaries; and (2) simple parameterizations of the settling velocity and the critical shear stress. Sensitivity studies confirm the importance of the advection of fine-grained suspended sediments in the central waters of the English Channel exhibiting benefits... |
Tipo: Text |
Palavras-chave: ROMS; Satellite; MERIS; MODIS; Tide; Wave. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00276/38766/37307.pdf |
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Santos,Urânia Amaral dos; Alvarez,Martin Roberto; Schilling,Ana Cristina; Strenzel,Gil Marcelo Reuss; Pendu,Yvonnick Le. |
We analyzed the influence of time, tide and water depth on the activity and spatial distribution of estuarine dolphins Sotalia guianensis in Pontal Bay, Ilhéus, Brazil. Direct observations were carried out at four fixed points from January to December of 2006. Estuarine dolphins were sighted in 11 out of 12 months and in 30% of 181 sampling periods. The average group size, which was 3.75 ± 1.59 (n = 64), did not vary significantly by month (Kruskal-Wallis, H = 10.6729; p = 0.3836). Infants and adults represented 18 and 82% of the individuals whose age we were able to determine, respectively. Estuarine dolphins were more frequently present than expected in areas deeper than 3 m (regression GLM, z = 3.773; p = 0.0002). The animals were more frequently... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dolphin; Behavior; Time of the day; Tide; Water depth; Estuarine fauna. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032010000200007 |
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Hernández Morales,Dannys Paola; Romaña Torres,Yorlenys; Jaramillo-Vélez,Alfredo; Pelegrí,Josep L.; Toro,Vladimir G.. |
ABSTRACT Good knowledge of the coastal circulation patterns is essential for a proper management of the coastline, especially in areas with a high anthropic pressure. In order to determine the main characteristics of the coastal currents in the Gulf of Urabá, the seasonal patterns of surface circulation were measured and analyzed during times of high and low rainfall along 6 km of coastline, between the Punta de Las Vacas and Punta Yarumal coastal spit systems, in the municipality of Turbo, Antioquia. These measurements were made with surface drifters, which were launched at different tide stages and tracked for time periods based on the semi-diurnal cycle. The in-situ measurements were analyzed alongside tide and wind data from a climatic station located... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Surface circulation; Wind; Tide; Drifters; Coastal currents.. |
Ano: 2021 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612021000200009 |
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Kolm,Hedda Elisabeth; Andretta,Lucimar. |
The influence of tidal phase on bacteria abundance in surface waters was studied in five stations along the Perequê tidal creek (Paraná State, Brazil), at spring and neap low and high tides in July 1999. The stations were located from the mouth (St.1) to the creek's head (St. 5). The following parameters were analyzed: salinity, temperature, pH, dissolved oxygen, total carbon dioxide, seston, particulate organic matter, pluviosity, chlorophyll "a", total heterotrophic bacteria, bacterial biomass, cultivable heterotrophic aerobic halophilic and halophobic bacteria, total coliforms and Escherichia coli. The results showed that the highest values of salinity, pH and dissolved oxygen at stations 1 to 4 were registered during the spring high tide. The amount of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacteria; Tide; Tidal creek; Perequê; Paraná State. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000200002 |
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Registros recuperados: 16 | |
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