Consulta: subjectFacets:"Fluxes"
Registros recuperados: 21
Data/hora: 07/06/2024 10:53:37

Downward fluxes of particulate organic matter in coastal and oceanic areas off Chile: The role of the OMZ and functional groups of the plankton
Provedor de dados: 72
Autores: González,H E; Daneri,G; Menschel,E; Marchant,M; Pantoja,S; Hebbeln,D; Barria,C; Vera,R; Iriarte,J.
Vertical fluxes of particles have been estimated during the last decade in coastal and oceanic systems off central-southern Chile. Free-drifting, cylindrical sediment traps have been deployed below the mixing layer from coastal areas, while automatic, cone-shaped sediment traps have been anchored in deep oceanic areas. Vertical fluxes toward 2300 m depth off Coquimbo were dominated by calcium carbonate (~70 mg m-2 d-1) instead of particulate organic carbon (POC ~7 mg m-2 d-1), where foraminifers (Neogloboquadrina pachyderma) and faecal pellets of Euphausia mucronata and Oikopleura spp, played important roles as vehicles for carbonate and carbon, respectively. In coastal upwelling systems, (i. e. Concepción), the dominant vertical flux was POC, mainly...
Tipo: Journal article
Palavras-chave: Particulate organic matter; Fluxes; Oxygen minimum zone; Zooplankton functional groups; Sediment traps; Central Chile.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300007

Water and nutrient fluxes as indicators for the stability of different land use systems on the terra firme near Manaus.
Provedor de dados: 14
Autores: SHIFT PROJECT ENV 45.
This second annual report of the project summarizes the activities between January and December 1996. During this year, the project left the preparotory stage of purchasing, importing and installing equipment and entered into the stage of routine data collection and analysis.The report is divided into two parts. In the main part, the project team is presented and its acitivities during the year 1996 are briefly summarized. The annexes give detailed accounts of selected research acitivities of the project. Despite numerous problems, all project activities were in principle successful, and there were no major changes to the time plan of the project. The root distribution studies were completed. Significant progress was made in soil physical studies, soil...
Tipo: Outras publicações técnicas (INFOTECA-E)
Palavras-chave: Area abandonada; Agrofloresta; Fluxo; Brasil; Amazonas; Tropical rain forest; Agroforest; Fluxes; Analysis; Água; Análise; Conservação do Solo; Floresta Tropical Úmida; Nutriente; Environmental degradation; Nutrients; Soil conservation; Water.
Ano: 1997
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/667417

Calibração da técnica de Time Domain Reflectometry (TRD) para avaliação da umidade do solo, em um Latossolo Amarelo, textura muito argilosa, com diferentes valores de densidade aparente do solo - avaliação no campo.
Provedor de dados: 14
Autores: TEIXEIRA, W. G.; FACCIN, O. P.; AZEVEDO, C. P. de; HUWE, B.; SCHROTH, G.
Avaliação de umidade volumetrica do solo pela técnica de time Domain Reflectometry (TDR) para Latossolo Amarelo (Xanthic ferralsol - FAO) textura muito argilosa, com diferentes valores de p. Foram determinados os coeficientes de determinacao ajustada (R2) e o erro padrao da media. Realizou-se um ajuste por regressao multipla para P e E, selecionando-se as variaveis que contribuiam significativamente para o modelo por procedimentos de selecao stepwise. Como a variacao dos valores de p esta diretamente relacionada ao uso do solo (especie presente e o manejo praticado), foram observadas importantes diferencas entre as P das areas cultivadas e as da floresta primaria. Os valores reduzidos de P proxima as plantas de pupunha (Bactris gasipaes H.B.K.) em relacao...
Tipo: Capítulo em livro técnico (INFOTECA-E)
Palavras-chave: Propriedade fisica; Fluxo; Brasil; Amazonas; Tropical rain forest; Moisture; Fluxes; Água; Bactris Gasipaes; Cupuaçu; Floresta Tropical Úmida; Kudzu; Pueraria Phaseoloides; Pupunha; Solo; Theobroma Grandiflorum; Umidade; Uso da Terra; Density; Land use; Physical properties; Soil; Water.
Ano: 1997
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/667398

Changes in seabed morphology, mud temperature and free gas venting at the Håkon Mosby mud volcano, offshore northern Norway, over the time period 2003-2006
Provedor de dados: 5
Autores: Foucher, Jean-paul; Dupre, Stephanie; Scalabrin, Carla; Feseker, Tomas; Harmegnies, Francois; Nouze, Herve.
The Håkon Mosby mud volcano is a 1.5-km-diameter geological structure located on the Southwest Barents Sea slope at a water depth of 1,270 m. High-definition seabed mapping of the mud volcano has been carried out in 2003 and 2006. A comparative analysis of the bathymetry and backscatter maps produced from the two surveys shows subtle morphological changes over the entire crater of the mud volcano, interpreted to be the consequence of mud eruption events. Mud temperature measurements point to a persistently warm mud at shallow depth in the crater. This is explained by upward fluid advection, rather than conductive cooling of mud flows. The small-scale spatial variability in the temperature distribution may be related to mud outflows or changes in the fluid...
Tipo: Text
Palavras-chave: Sw barents sea; Cold seep ecosystems; Fluid flow; Methane; Sediment; Onshore; Fluxes; Margin; Water.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00004/11527/10261.pdf

Influence of oyster culture on biogeochemistry and bacterial community structure at the sediment-water interface
Provedor de dados: 5
Autores: Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis.
Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor...
Tipo: Text
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf

Influence d'un élevage ostréicole sur les flux de nutriments et d'oxygène dans un écosystème lagunaire
Provedor de dados: 5
Autores: Mazouni, Nabila; Deslous-paoli, Jean-marc; Landrein, Sonia.
The impact of suspended oyster culture (Crassostrea gigas, Thunberg) on oxygen and nutrient fluxes has been studied in situ, in a coastal lagoon (Thau, France), during a seasonal cycle. On the first plan of the multiple factorial correspondences analysis (MCA), seasons were well discriminated. The fluxes were maximum in summer and minimum in winter. However, this seasonal pattern was not only linked to the water temperature, as autumn and spring (similar temperatures of about 12 degrees C) were distinct in the second factorial plan (2.3). Oxygen uptake by the oyster cultures varied between 0 mu mol m(-2) h(-1) (January) and 11 823 +/- 377 mu mol m(-2) h(-1) (July). Ammonia and nitrate-nitrites were released into the water column respectively at a rate of...
Tipo: Text
Palavras-chave: Oxygen; Nutrients; Fluxes; Oyster culture; Oxygène; Nutriments; Flux; Elevage ostréicole.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-840.pdf

Insights into decadal North Atlantic sea surface temperature and ocean heat content variability from an eddy-permitting coupled climate model
Provedor de dados: 5
Autores: Moat, B. I.; Sinha, B.; Josey, S. A.; Robson, J.; Ortega, P.; Sévellec, Florian; Holliday, N. P.; Mccarthy, G. D.; New, A. L.; Hirschi, J. J.-m.
An ocean mixed layer heat budget methodology is used to investigate the physical processes determining subpolar North Atlantic (SPNA) sea surface temperature (SST) and ocean heat content (OHC) variability on decadal-multidecadal timescales using the state-of-the-art climate model HadGEM3-GC2. New elements include development of an equation for evolution of anomalous SST for interannual and longer timescales in a form analogous to that for OHC, parameterization of the diffusive heat flux at the base of the mixed layer and analysis of a composite AMOC event. Contributions to OHC and SST variability from two sources are evaluated i) net ocean-atmosphere heat flux and ii) all other processes, including advection, diffusion and entrainment for SST. Anomalies in...
Tipo: Text
Palavras-chave: Atmosphere-ocean interaction; Climate variability; Energy budget; Balance; Fluxes; Heat budgets; Fluxes; Surface temperature.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00502/61395/65060.pdf

Mercury speciation and exchanges at the air-water interface of a tropical artificial reservoir, French Guiana
Provedor de dados: 5
Autores: Muresan Paslaru, Bogdan; Cossa, Daniel; Richard, S; Burban, B.
The distribution and speciation of mercury (Hg) in air, rain, and surface waters from the artificial tropical lake of Petit-Saut in French Guiana were investigated during the 2003/04 period. In the air, total gaseous mercury (TGM) at the dam station averaged 12 +/- 2 pmol m(-3) of which &gt; 98% was gaseous elemental mercury (GEM). GEM distribution depicted a day-night cycling with high concentrations (up to 15 pmol m(-3)) at dawn and low concentrations (down to 5 pmol m(-3)) at nightfall. Reactive gaseous mercury (RGM) represented &lt; 1% of the GEM with a mean concentration of 4 3 fmol m(-3). Diel RGM variations were negatively related to GEM. In the rain, the sum of all Hg species in the unfiltered (HgTUNF) averaged 16 +/- 112 pmol L-1. Temporal...
Tipo: Text
Palavras-chave: Fluxes; Speciation; Mercury; Artificial reservoir; Atmosphere.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3329.pdf

Composition of biofouling communities on suspended oyster cultures: an in situ study of their interactions with the water column
Provedor de dados: 5
Autores: Mazouni, Nabila; Gaertner, J; Deslous-paoli, Jean-marc.
This study was based on in situ experiments conducted in a shellfish lagoon (Thau, France) to determine the interactions between suspended oyster Crassostrea gigas Thunberg cultures and their environment at a seasonal scale. Three groups of descriptors were considered simultaneously during the course of the study: the taxonomic composition of an oyster culture unit (OCU), the nutrient and oxygen exchanges at the OCU-water interface (fluxes) and the water-column characteristics (water). We used a multiple factorial analysis (MFA) to assess in a single reference frame: (1) the seasonal organisation of the taxonomic groups which compose the OCU and (2) the interactions between this multispecific assemblage and the water column. We found strong seasonal...
Tipo: Text
Palavras-chave: Ascidians; Fluxes; Multicompartment approach; Biofouling; Oyster culture.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/1996/publication-809.pdf

Les apports en sels nutritifs dans l'estuaire de la Seine
Provedor de dados: 5
Autores: Guillaud, Jean-francois.
In this report, nutrient concentrations and fluxes are evaluated at the Caudebec station in the Seine estuary; with a mean river flow of 413 m3/s, the values of mean interannual fluxes are 46 300 t per year for silicium, 90 700 t per year for total nitrogen and 11 000 t per year for total phosphorus ; since 1984, there is a decrease of phosphate fluxes (3 % per year) and an increase of total nitrogen fluxes (2 % per year).
Tipo: Text
Palavras-chave: Sels nutritifs; Estuaire Seine; Flux; Nutrients; Seine estuary; Fluxes.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00425/53660/54499.pdf

A Surface Ocean CO2 Reference Network, SOCONET and Associated Marine Boundary Layer CO2 Measurements
Provedor de dados: 5
Autores: Wanninkhof, Rik; Pickers, Penelope A.; Omar, Abdirahman M.; Sutton, Adrienne; Murata, Akihiko; Olsen, Are; Stephens, Britton B.; Tilbrook, Bronte; Munro, David; Pierrot, Denis; Rehder, Gregor; Magdalena Santana-casiano, J.; Mueller, Jens D.; Trinanes, Joaquin; Tedesco, Kathy; O'Brien, Kevin; Currie, Kim; Barberols, Leticia; Telszewski, Maciej; Hoppema, Mario; Ishii, Masao; Gonzalez-davila, Melchor; Bates, Nicholas R.; Metzl, Nicolas; Suntharalingam, Parvadha; Feely, Richard A.; Nakaoka, Shin-ichiro; Lauvset, Siv K.; Takahashi, Taro; Steinhoff, Tobias; Schuster, Ute.
The Surface Ocean CO2 NETwork (SOCONET) and atmospheric Marine Boundary Layer (MBL) CO2 measurements from ships and buoys focus on the operational aspects of measurements of CO2 in both the ocean surface and atmospheric MBLs. The goal is to provide accurate pCO(2) data to within 2 micro atmosphere (mu atm) for surface ocean and 0.2 parts per million (ppm) for MBL measurements following rigorous best practices, calibration and intercomparison procedures. Platforms and data will be tracked in near real-time and final quality-controlled data will be provided to the community within a year. The network, involving partners worldwide, will aid in production of important products such as maps of monthly resolved surface ocean CO2 and air-sea CO2 flux...
Tipo: Text
Palavras-chave: Carbon dioxide; Network; Oceanography; Fluxes; Best practices.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00675/78725/80992.pdf

Variability of the Heat and Salt Budget in the Subtropical Southeastern Pacific Mixed Layer between 2004 and 2010: Spice Injection Mechanism
Provedor de dados: 5
Autores: Kolodziejczyk, Nicolas; Gaillard, Fabienne.
The mixed layer heat and salt budget in the southeastern subtropical Pacific are estimated using 7 years (2004-10) of Argo-profiling float data, surface fluxes, precipitation, surface velocity data, and wind observations and reanalysis. In this region, the mixed layer heat budget is characterized by a strong annual cycle mainly modulated by the shortwave radiation annual cycle. During the austral fall and winter, the shortwave radiation input minimum is overwhelmed by the heat loss mainly because of the latent heat flux. The mixed layer salt budget also presents a strong annual cycle with a minimum of salt content during the late austral winter. In contrast with the heat budget, the salt budget is mainly driven by the unresolved terms computed as the...
Tipo: Text
Palavras-chave: Mixed layer; Heat budgets; Fluxes; Salinity; In situ oceanic observations; Interannual variability; Seasonal cycle.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00155/26587/24722.pdf

Assessment of the quantities of herbicides and nutrients brought down by the river Charente to the coast and modelling of the dispersion of atrazine in the Marennes-Oleron bay
Provedor de dados: 5
Autores: Munaron, Dominique; Dubernet, Jf; Delmas, F; Stanisiere, Jean-yves; Scribe, P.
Our study aims at making progress the estimate of herbicide and nutrient inputs to the Marennes-Oleron bay which could influence summer oysters mortalities, and to bring, a better understanding of the impact on coastal ecosystems by modelling the dynamics of these compounds in the shellfish-farming area. The development of a strategy adapted to the river Charente and its estuary reveals that agricultural activity on the watershed area is omnipresent, as well on the level of the nitrogen as on the one of herbicides contributions. It is thus necessary to specify Charente fluxes, which is the main tributary of the Marennes-Oleron bay, in order to better characterize its impact on shell fish-farming activity. Hydrodynamic modelling will constitute an...
Tipo: Text
Palavras-chave: Marennes Oleron bay; River Charente; Modelling; Fluxes; Nutrients; Herbicides.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-3612.pdf

An Assessment of the Precision and Confidence of Aquatic Eddy Correlation Measurements
Provedor de dados: 5
Autores: Donis, Daphne; Holtappels, Moritz; Noss, Christian; Cathalot, Cecile; Hancke, Kasper; Polsenaere, Pierre; Wenzhoefer, Frank; Lorke, Andreas; Meysman, Filip J. R.; Glud, Ronnie N.; Mcginnis, Daniel F.
The quantification of benthic fluxes with the aquatic eddy correlation (EC) technique is based on simultaneous measurement of the current velocity and a targeted bottom water parameter (e.g., O2, temperature). High-frequency measurements (64 Hz) are performed at a single point above the seafloor using an acoustic Doppler velocimeter (ADV) and a fast-responding sensor. The advantages of aquatic EC technique are that 1) it is noninvasive, 2) it integrates fluxes over a large area, and 3) it accounts for in situ hydrodynamics. The aquatic EC has gained acceptance as a powerful technique; however, an accurate assessment of the errors introduced by the spatial alignment of velocity and water constituent measurements and by their different response times is...
Tipo: Text
Palavras-chave: Turbulence; Boundary layer; Fluxes; Instrumentation/sensors; Optimization; Experimental design.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00275/38577/37102.pdf

Subantarctic Mode Water Formation, Destruction, and Export in the Eddy-Permitting Southern Ocean State Estimate
Provedor de dados: 5
Autores: Cerovecki, Ivana; Talley, Lynne D.; Mazloff, Matthew R.; Maze, Guillaume.
Subantarctic Mode Water (SAMW) is examined using the data-assimilating, eddy-permitting Southern Ocean State Estimate, for 2005 and 2006. Surface formation due to air–sea buoyancy flux is estimated using Walin analysis, and diapycnal mixing is diagnosed as the difference between surface formation and transport across 30°S, accounting for volume change with time. Water in the density range 26.5 &lt; σθ &lt; 27.1 kg m−3 that includes SAMW is exported northward in all three ocean sectors, with a net transport of (18.2, 17.1) Sv (1 Sv ≡ 106 m3 s−1; for years 2005, 2006); air–sea buoyancy fluxes form (13.2, 6.8) Sv, diapycnal mixing removes (−14.5, −12.6) Sv, and there is a volume loss of (−19.3, −22.9) Sv mostly occurring in the strongest SAMW formation...
Tipo: Text
Palavras-chave: Atmosphere-ocean interaction; Buoyancy; Fluxes; Ocean circulation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00154/26487/24596.pdf

The biogeochemistry of mercury at the sediment water interface in the Thau lagoon. 1. Partition and speciation
Provedor de dados: 5
Autores: Muresan Paslaru, Bogdan; Cossa, Daniel; Jezequel, D; Prevot, F; Kerbellec, S.
Solid sediment, pore and epibenthic waters were collected from the Thau lagoon (France) in order to study the post depositional partition and mobility of mercury and monomethylmercury in an organic rich sediment. Total Hg (HgT) and monomethymercury (MMHg) profiles were produced in both dissolved and solid phases. The distribution of HgT in the solid appeared to be related to the historical changes in the Hg inputs into the lagoon. HgT was in equilibrium between solid and solution in the sulfidic part of the cores, with a mean log Kd of 4.9 +- 0.2. The solid appeared to be a source of HgT for pore water in the upper oxic to suboxic parts of the cores. The MMHg represented a small fraction of HgT: 3-15 % and 0.02-0.80 % in the dissolved and in the solid...
Tipo: Text
Palavras-chave: Fluxes; Partition; Sediment; Lagoon; Methylmercury; Mercury.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2006/publication-2083.pdf

Strong Indian Ocean sea surface temperature signals associated with the Madden-Julian Oscillation in late 2007 and early 2008
Provedor de dados: 5
Autores: Vialard, Jerome; Foltz, G. R.; Mcphaden, M. J.; Duvel, J. P.; De Boyer Montegut, Clement.
A moored buoy was recently deployed at 8 degrees S, 67 degrees E in the shallow thermocline region of the Indian Ocean known as "Seychelles-Chagos Thermocline Ridge'' (SCTR), where the Madden Julian Oscillation (MJO) is associated with strong sea surface temperature (SST) variability. We use observations from this mooring to describe the oceanic signature of two MJOs between November 2007 and February 2008. The four-month average upper ocean heat balance was largely between heating by atmospheric forcing (2.0 +/- 0.3 degrees C/month) and a significant cooling by subsurface processes (-2.2 +/- 0.8 degrees C/month), consistent with climatological Ekman pumping in the region. The two MJO events resulted in strong intraseasonal SST variations (1.5 to 2 degrees...
Tipo: Text
Palavras-chave: Layer heat balance; Paific; Perturbations; Prediction; Fluxes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00185/29636/27988.pdf

La qualité des eaux dans l'Estuaire de la Gironde. 1- Traitement des données. 2 - Synthèse
Provedor de dados: 5
Autores: Maurice, Laurence.
The main problem of the Girond estuary is a pollution by the cadmium. During this last ten years, the good quality of the water is proved by the analysis of the main physico - chemical and biochemical parameters and bacteria. But since 1989, straight to the Blayais power station, the BOD5 varied between 2 and 3,5 mg.l-1 and a diminution of the dissolved oxygen has been observed; it's probably caused by the accumulation of biodegradable organic matter in the maximum turbidity zone during years characterized by low river flows. For average river flow, urban discharges takes part for 20 % in total fluxes of BD05; in 1991, this part attempts 35 %. During the last 7 years, the pluriannual evolution of the nitrate concentrations measured in the Garonne river...
Tipo: Text
Palavras-chave: Oxygène; Sels nutritifs; Matière organique; Bactéries; Apports; Estuaire Gironde; Oxygen; Nutrients; Organic matter; Bacteria; Fluxes; Gironde estuary.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00037/14855/12178.pdf

Validation and analysis of ocean parameters using ASCAT data
Provedor de dados: 5
Autores: Bentamy, Abderrahim; Ardhuin, Fanny; Croize-fillon, Denis; Queffeulou, Pierre.
This project aims to investigate the quality of ASCAT measurements as well as their use for oceanographic purposes. The accuracy of ASCAT retrievals will be mainly based on the use of collocated data from moored buoys, numerical weather prediction models, and satellites. The resulting collocated data will be used to explore the accuracy of the geophysical model function which relates the backscatter coefficients to surface wind vectors, as well as to assess the quality of ASCAT vector winds at global and local scales. Once this objective reached, it will enable to fully utilize the MetOp data for oceanographic applications. They will contribute to evaluate various estimates of ocean surface flux parameters required to force ocean general circulation...
Tipo: Text
Palavras-chave: Fluxes; Sea ice; Wind; Scatterometer; ASCAT; MetOp; Flux; Glaces de mer; Vent; Diffusiomètre; ASCAT; MetOp.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-1272.pdf

Indo-Pacific Sea surface temperature perturbations associated with intraseasonal oscillations of tropical convection
Provedor de dados: 5
Autores: Duvel, Jean Philippe; Vialard, Jerome.
The intraseasonal variability (ISV; 20-90 days) of the SST is examined using 7 yr of data from the Tropical Rainfall Measuring Mission's (TRMM) Microwave Imager ( TMI). The ISV of the SST is larger in the summer hemisphere and in regions of relatively small ocean mixed layer depth (MLD). For these regions, the reddening of the SST spectrum in regard to the surface flux spectrum suggests that the ISV of the SST is mostly controlled by the integration of the local surface forcing by ocean mixed layer. However, the precise origin of large-scale organized perturbations of the SST also depends on region and season. Since the ISV of the convection is an intermittent phenomenon, the local mode analysis (LMA) technique is used to detect only the ensemble of...
Tipo: Text
Palavras-chave: Madden julian oscillation; Western indian ocean; Summer monsoon; Mixed layer; Warm pool; Variability; Fluxes; Model; Atmosphere; Bengal.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00185/29638/27986.pdf

Comportement du cadmium et du mercure lors de la diagenèse précoce et flux à l'interface eau-sédiments en zone littorale
Provedor de dados: 5
Autores: Gonzalez, Jean-louis.
The early diagenesis of Cd and Hg has been studied in different coastal areas (vasière Ouest-Gironde, Pertuis d'Antioche, baie de Marennes-Oléron). For these two metals, the fluxes at the sediment-water interface have been calculated. Considering only molecular diffusion, the diffusionnal fluxes of Cd and Hg to the colurnn water are negligible with regard to both the particular fluxes to the sediments and the inputs of the "Gironde" and "Charente" ·,estuaries. The take into account of the different processes which affect the ex changes at the interface (erosion, bioturbation) permits more realistic an estimation of the role of sediments in the geochemical cycle of Cd and Hg. The results show that up to 50% of particular Cd and Hg which are integrated into...
Tipo: Text
Palavras-chave: Cadmium; Mercure; Eaux intrstitielles; Diagenèse précoce; Flux; Interface eaux-sédiments; Bioturbation; Modélisation; Cadmium; Mercury; Pore waters; Early diagenesis; Fluxes; Sediment-water interface; Bioturbation; Modelling.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00442/55402/56920.pdf