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| Registros recuperados: 167 | |
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| LESSA,GUILHERME C.; BITTENCOURT,ABÍLIO C.S.P.; BRICHTA,ARNO; DOMINGUEZ,JOSÉ M. L.. |
| Todos os Santos Bay is a large (<img ALIGN="BOTTOM" BORDER="0" SRC="http:/img/fbpe/aabc/v72n4/0052img1.gif" ALT="$ \approx$"> 1000 km²), structurally controlled tidal bay in northeast Brazil. Three main drainage basins debouch into the bay, providing a mean freshwater discharge of 200 m³/s (prior to 1985), or less than 1% of the spring tidal discharge through the bay mouth. Based on the result of several sedimentological studies performed in the 1970's, five surface sedimentary facies were identified inside the bay, namely i) transgressive siliciclastic marine sand facies; ii) transgressive bay sand-mud facies; iii) a transgressive carbonate marine sand facies; iv) regressive bay-mud facies, and v) regressive fluvial sand facies. The spatial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Estuary; Sediment; Stratigraphy; Holocene. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000400008 |
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| Cesar,Augusto; Abessa,Denis Moledo de Souza; Pereira,Camilo Dias Seabra; Santos,Aldo Ramos; Fernández,Nuria; Choueri,Rodrigo Brasil; DelValls,Tomas Angel. |
| In this work, multivariate and numeric methods were used to integrate the chemical and ecotoxicological data obtained for the sediments from the Santos Estuarine System, and for the vicinity of the discharges of the Submarine Sewage Outfall of Santos, in order to establish more accurately the environmental risks, identify the priority areas and thus provide guidance to control the programs and public policies. For both the datasets, the concentrations which exceeded numeric sediment guidelines tended to be associated to toxicity. For the estuary, this trend was corroborated by the correlations between the toxicity and Cu and PAHs levels, whereas for the sewage outfall region, this was observed through the correlation between the toxicity and Hg contents.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sediment; Contamination; Toxicity; Tiburonella viscana; Environmental risk assessment. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000100028 |
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| Gomez, E; Millet, B; Picot, B. |
| The Mejean-Perols Lagoon is situated on the French Mediterranean coast. It is a small (747 ha) and shallow (70 cm) lagoon. Some treated effluent from Montpellier flows into this hypereutrophic lagoon. The cartography of C, N and P concentrations in the sediment was studied based on 35 bottom samples. The nitrogen and organic carbon concentrations were more or less homogeneous, the highest concentrations being found in the middle of the lagoon. The phosphate was principally bound onto the sediment in the west zone. The observed distribution was independent of grain size, the distribution of which was rather homogeneous. In this lagoon water circulation is wind induced. Four different water flow structures were observed, as functions of the prevailing winds... |
| Tipo: Text |
Palavras-chave: Sédiment; Lagune côtière; Hydrodynamique; Sels nutritifs; Carbone; Sediment; Coastal lagoon; Hydrodynamics; Nutrients; Carbon. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43642/43247.pdf |
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| Tanty, Cyrielle; Valet, Jean-pierre; Carlut, Julie; Bassinot, Franck; Zaragosi, Sebastien. |
| Turbiditic events are mostly avoided in paleomagnetic studies and therefore their remanence and magnetic properties are poorly described. Turbidites are exempt of bioturbation and potentially provide pertinent information about depositional remanence. We studied four quaternary turbidites of different origins in marine sediment cores. Upward fining of both magnetic and sedimentary fractions indicates that coarser grains reached the bottom first. We observe a progressive shallowing of the magnetic inclinations between the upper and bottom layers of the turbidites that increases with the size of the events and obeys a simple linear scaling law. Measurements of magnetic anisotropy suggest that hydrodynamic conditions prevailing during deposition seem to be... |
| Tipo: Text |
Palavras-chave: Detrital remanence; Turbidite; Sediment; Rock magnetism; Magnetization. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53226/54792.pdf |
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| Giorgetti, Alessandra; Lipizer, Marina; Molina Jack, Maria Eugenia; Holdsworth, Neil; Jensen, Hans Mose; Buga, Luminita; Sarbu, George; Iona, Athanasia; Gatti, Julie; Larsen, Martin; Fyrberg, Lotta; Østrem, Ann Kristin; Schlitzer, Reiner. |
| Tipo: Text |
Palavras-chave: Nutrients; Oxygen; Acidity; Contaminants; Sediment; Biota; Aggregated datasets. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00663/77519/79314.pdf |
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| Sultan, Nabil; Gaudin, Mathieu; Berne, Serge; Canals, Miquel; Urgeles, Roger; Lafuerza, Sara. |
| To improve understanding of evolution of submarine canyons, a three-dimensional slope-stability model is applied to Bourcart Canyon in the western Gulf of Lions in the Mediterranean Sea. The model builds on previous work by Chen and others, and it uses the upper bound theorem of plasticity to calculate the factor of safety of a kinematically admissible failing mass. Examples of three-dimensional failure surfaces documented in the literature were used to test the model formulation. Model application to Bourcart Canyon employed the results of a detailed stratigraphic analyses based on data acquired by swath bathymetry, sub-bottom profiling, high-resolution seismic reflection surveys, and piston coring. The sediment layers were also characterized using... |
| Tipo: Text |
Palavras-chave: Cascadia accretionary complex; Upper bound theorem; Stability analysis; Continental slope; Limit equilibrium; Western gulf; Offshore; Margin; Initiation; Sediment. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2410.pdf |
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| OLIVEIRA, M. D. de; CALHEIROS, D. F.. |
| A agricultura intensiva, pastagens cultivadas, garimpo, agroindústria e os efluentes urbanos estão entre os principais fatores que causam alterações ambientais no Pantanal e rios associados (Ferreira et. al., 1994). Estas atividades estão concentradas principalmente nas áreas de planalto e têm gerado aumentos no aporte de nutrientes e sedimentos para a planície. Um bom exemplo, é rio Taquari, um dos maiores tributários da bacia do alto rio Paraguai (Brasil; 1997). A bacia hidrográfica do rio Taquari está localizada entre as latitudes de 17°00'00''S e 20°00'00''S e as longitudes de 53°00'00''W e 58°00'00''W, abrangendo uma área de aproximadamente 65.023 km2, dentro da bacia do Alto Paraguai (BAP). No fim do alto curso, o rio Taquari recebe o rio Coxim com... |
| Tipo: Folhetos |
Palavras-chave: Assoreamento; Sólido suspenso; Característica; Rio Taquari; Sediment; Nutrient; Characteristic; Taquari river; Água; Limnologia; Nutriente; Sedimento; Limnology; Water. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810732 |
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| Roussel, Erwan; Sauvadet, Anne Laure; Allard, Jonathan; Chaduteau, Carine; Richard, Pierre; Cambon Bonavita, Marie-anne; Chaumillon, Eric. |
| In Marennes-Oleron Bay, a macro-tidal bay located on the French Atlantic coast, kilometer-scale acoustic turbidity reveals an accumulation of free gas in the sediment. Large concentrations of organic matter and rapid sedimentation rates provide ideal settings for biogenic methane cycling. We integrate seismic, sedimentologic, biogeochemical and molecular genetic approaches to determine whether microbial methane cycling is involved in this process. Here we show that the acoustic turbidity upper boundary matched with X-ray facies displaying fissures with the highest methane concentrations, demonstrating the existence of methane bubbles in the sediment. 16S rRNA and mcrA gene clone libraries were dominated by sequences affiliated to the three known ANME... |
| Tipo: Text |
Palavras-chave: Sediment; Methane; McrA; 16S rRNA; Archaea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6165.pdf |
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| Fagel, N; Dehairs, F; Andre, L; Bareille, G; Monnin, C. |
| We present excess Ba (Baxs) data (i.e., total Ba corrected for lithogenic Ba) for surface sediments from a north-south transect between the Polar Front Zone and the northern Weddell Gyre in the Atlantic sector and between the Polar Front Zone and the Antarctic continent in the Indian sector. Focus is on two different processes that affect excess Ba accumulation in the sediments: sediment redistribution and excess Ba dissolution. The effect of these processes needs to be corrected for in order to convert accumulation rate into vertical rain rate, the flux component that can be linked to export production. In the Southern Ocean a major process affecting Ba accumulation rate is sediment focusing, which is corrected for using excess (230)Th. This correction,... |
| Tipo: Text |
Palavras-chave: Excess Ba; Sediment; Southern Ocean; Export production. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33392/31868.pdf |
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| Pascal, P.y.; Dupuy, C; Mallet, C; Richard, P; Niquil, N. |
| The fate of benthic bacterial biomass in benthic food webs is a topic of major importance but poorly described. This paper describes an alternative method for evaluation of bacterial grazing rate by meiofauna and macrofauna using bacteria pre-enriched with stable isotopes. Natural bacteria from the sediment of an intertidal mudflat were cultured in a liquid medium enriched with 15NH4Cl. Cultured bacteria contained 2.9% of 15N and were enriched sufficiently to be used as tracers during grazing experiments. Cultured bacteria presented a biovolume (0.21 μm3) and a percentage of actively respiring bacteria (10%) similar to those found in natural communities. The number of Operational Taxon Units found in cultures fluctuated between 56 and 75% of that... |
| Tipo: Text |
Palavras-chave: Tracer; Stable isotope; Sediment; Grazing; Bacteria. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4296.pdf |
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| Lemes,Gilmar AF; Kist,Luiza W; Bogo,Mauricio R; Yunes,João S. |
| Background Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. Methods [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosastrain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodegradation; Microcystin; Sediment; Patos Lagoon; Estuary; Brazil. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992015000100313 |
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| Petit, Fabienne; Clermont, Olivier; Delannoy, Sabine; Servais, Pierre; Gourmelon, Michele; Fach, Patrick; Oberle, Kenny; Fournier, Matthieu; Denamur, Erick; Berthe, Thierry. |
| The aim of this study was to investigate the diversity of the E. coli population, focusing on the occurrence of pathogenic E. coli, in surface water draining a rural catchment. Two sampling campaigns were carried out in similar hydrological conditions (wet period, low flow) along a river continuum, characterized by two opposite density gradients of animals (cattle and wild animals) and human populations. While the abundance of E. coli slightly increased along the river continuum, the abundance of both human and ruminant-associated Bacteroidales markers, as well as the number of E. coli multi-resistant to antibiotics, evidenced a fecal contamination originating from animals at upstream rural sites, and from humans at downstream urban sites. A strong spatial... |
| Tipo: Text |
Palavras-chave: Water; Sediment; Pathogenic E. coli; Virulence gene; Shiga toxin. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00378/48887/49328.pdf |
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| Moukrim, A; Chiffoleau, Jean-francois; Cheggour, M; Burgeot, Thierry. |
| Monthly samples of sediment were collected from the Souss estuary, to determine the changes which have occurred in the concentrations of ten metals between 2001 when the low estuary was receiving the wastewaters from Agadir city and 2003 after stopping the sewage dumping. The annual contents of Cu, Fe, Zn (in 2001) and those of Cr, Cu, Fe, Mn, Ni, Pb, and Zn (in 2003) showed significant correlations with those of Al, indicating that fluctuations of their concentrations were only due to those of the aluminosilicate fraction of the clayey sediment. After normalization of these metallic concentrations in relation to those of Al, the contents of the different metals showed insignificant correlations between both years, except for Zn which significantly dropped... |
| Tipo: Text |
Palavras-chave: Souss estuary; Wastewater; Sediment; Metal contamination. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5923.pdf |
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| Ouillon, S.; Douillet, Pascal; Lefebvre, J. P.; Le Gendre, Romain; Jouon, Aymeric; Bonneton, P.; Fernandez,; Chevillon, C.; Magand, O.; Lefevre, J.; Le Hir, Pierre; Laganier, R.; Dumas, Franck; Marchesiello, P.; Madani, A. Bel; Andrefouet, S.; Panche, J. Y.; Fichez, R.. |
| The south-west lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave set-up induced by the swell breaking on the reef barrier... |
| Tipo: Text |
Palavras-chave: Hydrodynamics; Suspended sediment; New Caledonia; Coral reef lagoon; Sediment; Turbidity; Resuspension. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12526/9401.pdf |
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| Dou, Yanguang; Yang, Shouye; Liu, Zhenxia; Clift, Peter D.; Yu, Hua; Berne, Serge; Shi, Xuefa. |
| The Okinawa Trough is a natural laboratory for the study of later Quaternary land-ocean interaction and paleoenvironmental changes. In this study we reconstruct the evolution of clay mineral assemblages in Core DGKS9604 retrieved from the central Okinawa Trough. Illite dominates the clay mineral compositions, with average contents above 60%. Clay mineral evolution since 28 ka is closely related to changes in sediment provenance and paleoenvironment. Sea level rise and the strength of the Kuroshio Current control the dispersal and deposition of clays on the East China Sea shelf and in the Okinawa Trough, and thus, determine the clay mineral compositions in the core sediments. During the late last glacial period (28.0-14.0 ka), the paleo-Changjiang River... |
| Tipo: Text |
Palavras-chave: Clay mineral; Sediment; Provenance; East China Sea; Okinawa Trough. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11367/7977.pdf |
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| Registros recuperados: 167 | |
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