Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: 

RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 39
Primeira ... 12 ... Última
Imagem não selecionada

Imprime registro no formato completo
Variation horizontale du flux particulaire à micro- et méso-échelle dans la plaine abyssale de Californie (4 100 m de profondeur) ArchiMer
Crassous, Philippe; Khripounoff, Alexis.
Nine sediment traps were assembled in triplicate on a frame and deployed at 100 m above the bottom in the California abyssal plain (4 100 m depth) for ten days. The distances between traps were from 30 cm to 11 km. The main flux measured during this period was 167 mg m(-2) day(-1) with a minimum of 43 mg m(-2) d(-1) and a maximum of 283 mg m(-2) d(-1). This high variation of the particulate flux at the kilometric scale was also observed at a metric scale: for example, the particulate flux measured with one of triplicate traps was equal to 82.3 +/- 46.5 mg m(-2) d(-1) (more than 50 % of variation) between traps distant of less than 1 m. To explain this heterogeneity of the flux measurement, some hypotheses are developed in this study: sampling artefact,...
Tipo: Text Palavras-chave: SEDIMENT TRAPS; DEEP SEA; HORIZONTAL FLUX VARIATION.
Ano: 1994 URL: http://archimer.ifremer.fr/doc/00098/20885/18499.pdf
Imagem não selecionada

Imprime registro no formato completo
Remises en suspension sédimentaires observées en Méditerranée par 2 000 m de profondeur à l'aide de pièces à particules ArchiMer
Crassous, Philippe; Khripounoff, Alexis; Larosa, Jacques; Miquel, Juan-carlos.
Four sediment traps of two different types and two current meters were deployed fixed to two identical moorings, at a depth of 2 000 m, off the coast at Nice, for 70 days between April and June 1987. The particulate flux measured with sediment traps decreased from 1 000 to 95 mg/m2/day during this experiment. The carbonate carbon concentration of the particles also decreased during this period; organic carbon concentrations varied inversely with the flux, increasing from 1.8 to 3.7 % of the particle dry weight. It is concluded that these changes reveal the presence of a deep-sea storm with a significant resuspension of sediment to a height greater than 200 m (distance of the traps from the bottom). By the end of the experiment, identical sediment traps had...
Tipo: Text
Ano: 1991 URL: http://archimer.ifremer.fr/doc/00101/21244/18859.pdf
Imagem não selecionada

Imprime registro no formato completo
Ecophysiological differences between vesicomyid species and metabolic capabilities of their symbionts influence distribution patterns of the deep‐sea clams ArchiMer
Cruaud, Perrine; Decker, Carole; Olu, Karine; Arnaud-haond, Sophie; Papot, Claire; Le Baut, Jocelyn; Vigneron, Adrien; Khripounoff, Alexis; Gayet, Nicolas; Cathalot, Cecile; Caprais, Jean-claude; Pignet, Patricia; Godfroy, Anne; Cambon Bonavita, Marie-anne.
This study provides an analysis of vesicomyid bivalve–symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on‐site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal...
Tipo: Text Palavras-chave: Deep-sea ecosystems; Guaymas Basin; Marine ecology; Pliocardinae bivalve; Sulfur storage; Vesicomyid movements.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00493/60426/64028.pdf
Imagem não selecionada

Imprime registro no formato completo
Rare earth elements and neodymium isotopes in sedimentary organic matter ArchiMer
Freslon, Nicolas; Bayon, Germain; Toucanne, Samuel; Bermell, Sylvain; Bollinger, Claire; Chéron, Sandrine; Etoubleau, Joel; Germain, Yoan; Khripounoff, Alexis; Ponzevera, Emmanuel; Rouget, Marie Laure.
We report rare earth element (REE) and neodymium (Nd) isotope data for the organic fraction of sediments collected from various depositional environments, i.e. rivers (n=25), estuaries (n=18), open-ocean settings (n=15), and cold seeps (n=12). Sedimentary Organic Matter (SOM) was extracted using a mixed hydrogen peroxide/nitric acid solution (20%-H2O2 – 0.02M-HNO3), after removal of carbonate and oxy-hydroxide phases with dilute hydrochloric acid (0.25M-HCl). A series of experimental tests indicate that extraction of sedimentary organic compounds using H202 may be complicated occasionally by partial dissolution of sulphide minerals and residual carbonates. However, this contamination is expected to be minor for REE because measured concentrations in H2O2...
Tipo: Text Palavras-chave: Organic matter; Rare earth elements; REE; Neodymium isotopes; ΕNd; Sediment; Boundary Exchange; Paleoceanography.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00191/30250/28682.pdf
Imagem não selecionada

Imprime registro no formato completo
HOT 96 News ArchiMer
Gaill, Francoise; Felbeck, Horst; Desbruyeres, Daniel; Lallier, Francois; Toulmond, A.; Alayse, Anne-marie; Briand, Patrick; Brulport, Jean-pierre; Caprais, Jean-claude; Chevaldonne, P.; Coail, Jean-yves; Cosson, R.; Crassous, Philippe; Delachambre, J.; Durif, C.; Echardour, L.; Herve, G.; Hourdez, Stephane; Jollivet, D.; Kerdoncuff, Jacques; Khripounoff, Alexis; Lechaire, J.p.; Pruski, Audrey; Ravaux, Juliette; Sarradin, Pierre-marie; Shillito, Bruce; Toullec, J.y.; Arndt, C.; Fisher, C.; Lutz, Richard; Childress, J..
Tipo: Text
Ano: 1996 URL: http://archimer.ifremer.fr/doc/00179/29003/27431.pdf
Imagem não selecionada

Imprime registro no formato completo
Spatial and temporal patterns of benthic macrofaunal communities on the deep continental margin in the Gulf of Guinea ArchiMer
Galeron, Joelle; Menot, Lenaick; Renaud, Nolwenn; Crassous, Philippe; Khripounoff, Alexis; Treignier, C.; Sibuet, M..
Density, taxonomic composition at higher taxon level and vertical distribution of benthic macrofaunal communities and sediment characteristics (pore water, nitrogen, organic carbon, sulfur, C/N ratio, n-alcohol biomarkers) were examined at three deep sites on the Congo-Gabon continental margin. This study was part of the multidisciplinary BIOZAIRE project that aimed at studying the deep benthic ecosystems in the Gulf of Guinea. Sampling of macrofaunal communities and of sediment was conducted during three cruises (January 2001, December 2001 and December 2003) at two downslope sites (4000 m depth), one located near the Congo submarine channel (15 km in the south) and the other one far from the channel (150km in the South). The third area located 8 km north...
Tipo: Text Palavras-chave: Deep sea; Distribution; Community structure; Macrofauna; Congo canyon; Congo Angola margin; Equatorial west Africa margin; Atlantic.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-7315.pdf
Imagem não selecionada

Imprime registro no formato completo
Dynamics of benthic copepods and other meiofauna in the benthic boundary layer of the deep NW Mediterranean Sea ArchiMer
Guidi-guilvard, L. D.; Thistle, D.; Khripounoff, Alexis; Gasparini, S..
A continuous high-resolution time-series survey of the hyperbenthic community and local environmental conditions was conducted in the benthic boundary layer (BBL) of the DYFAMED-BENTHOS station (43 degrees 24.61'N, 7 degrees 51.67'E at 2347 in depth in the NW Mediterranean) between January 1996 and April 1998 using bottom-moored sediment traps and a current meter. Sediment traps were set 4 m above the bottom. Hyperbenthos was collected as 'swimmers', i.e. those organisms that are alive when they enter the traps but are not part of the particle flux. Identification of these organisms showed that similar to 90%, were meiobenthic, Copepods dominated and comprised on average 75%, of total swimmers. They were followed by nauplii (12%), annelids (7.8%),...
Tipo: Text Palavras-chave: Biodiversity; Population growth; Emergence; Resuspension; Benthic storms; Hyperbenthos; Swimmers; Deep sea.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-7416.pdf
Imagem não selecionada

Imprime registro no formato completo
Natural and anthropogenic trace metals in sediments of the Ligurian Sea (Northwestern Mediterranean) ArchiMer
Heimbuerger, Lars-eric; Cossa, Daniel; Thibodeau, Benoit; Khripounoff, Alexis; Mas, Virginie; Chiffoleau, Jean-francois; Schmidt, Sabine; Migon, Christophe.
The magnitude and the chronology of anthropogenic impregnation by Hg and other trace metals of environmental concern (V, Cr, Ni, Cu, Zn, Ag, Cd and Pb, including its stable isotopes) in the sediments are determined at the DYFAMED station, a site in the Ligurian Sea (Northwestern Mediterranean) chosen for its supposed open-sea characteristics. The DYFAMED site (VD) is located on the right levee of the Var Canyon turbidite system, at the end of the Middle Valley. In order to trace the influence of the gravity current coming from the canyon on trace metal distribution in the sediment, we studied an additional sediment core (VA) from a terrace of the Var Canyon, and material collected in sediment traps at the both sites at 20 m above sea bottom. The patterns...
Tipo: Text Palavras-chave: Marine sediments; Sediment traps; Mercury; Trace metals; Lead isotopes; Geochronology.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00073/18435/16125.pdf
Imagem não selecionada

Imprime registro no formato completo
Variability in gas and solute fluxes through deep-sea chemosynthetic ecosystems inhabited by vesicomyid bivalves in the gulf of Guinea ArchiMer
Khripounoff, Alexis; Caprais, Jean-claude; Decker, Carole; Essirard, Mikael; Le Bruchec, Julie; Noel, Philippe; Olu, Karine.
We have studied two species of vesicomyid bivalves inhabiting different areas of sulfide-rich sediments in association with methane seepage at two pockmarks located at about 650 m and 3150 m depth, respectively, along the Gabon-Congo margin, and organic-rich sediments in the deepest zone (4950 m depth) of the Congo deep-sea fan. Benthic chambers Calmar were deployed on three study sites to assess gas and solute exchanges at the water-sediment interface. We recorded in situ measurements of oxygen, total carbon dioxide, ammonium, methane, and sulfide in two clam beds at each site. At all sites, irrespective of which the vesicomyid species are present, oxygen consumption was high and variable (28–433 mmol m−2 d−1) as was total carbon dioxide emission (36–1857...
Tipo: Text Palavras-chave: Benthic chamber; Cold-seep ecosystem; Reduced sediment; Gas fluxes; Vesicomyid bivalves; Gulf of Guinea.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00226/33746/32160.pdf
Imagem não selecionada

Imprime registro no formato completo
Respiration of bivalves from three different deep-sea areas: cold seeps, hydrothermal vents and organic carbon-rich sediments ArchiMer
Khripounoff, Alexis; Caprais, Jean-claude; Decker, Carole; Le Bruchec, J.; Noel, Philippe; Husson, Berengere.
We studied bivalves (vesicomyids and mytilids) inhabiting four different areas of high sulfide and methane production: 1) in the Gulf of Guinea, two pockmarks (650 m and 3150 m depth) and one site rich in organic sediments in the deepest zone (4950 m average depth), 2) at the Azores Triple Junction on the Mid-Atlantic Ridge, one hydrothermal site (Lucky Strike vent field, 1700 m depth). Two types of Calmar benthic chambers were deployed, either directly set into the sediment (standard Calmar chamber) or fitted with a tank to isolate organisms from the sediment (modified Calmar chamber), to assess gas and solute exchanges in relation to bivalve bed metabolism. Fluxes of oxygen, total carbon dioxide, ammonium and methane were measured. At the site with...
Tipo: Text Palavras-chave: Deep-sea; Benthic chamber; Vesicomyid and Mytilid bivalves; Respiration rate; Cold seep; Hydrothermal vent.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00341/45204/44614.pdf
Imagem não selecionada

Imprime registro no formato completo
Deep cold-water coral ecosystems in the Brittany submarine canyons (Northeast Atlantic): Hydrodynamics, particle supply, respiration, and carbon cycling ArchiMer
Khripounoff, Alexis; Caprais, Jean-claude; Le Bruchec, Julie; Rodier, Philippe; Noel, Philippe; Cathalot, Cecile.
The submarine canyons of the Brittany continental slope (Bay of Biscay–Northeast Atlantic) were studied to describe the conditions in which cold-water corals occur in these areas and their consequences for coral metabolism. Near-bottom current, oxygen, temperature, and particle flux, simultaneously measured for 2 yr at 850 m depth, revealed by spectral analysis the presence of several frequencies with a dominant semidiurnal tidal cycle and a current direction determined exclusively by the canyon topography. Sediment trap data also showed a seasonal input of material with a large peak of particles and carbon fluxes at the end of winter. Daily particle and carbon fluxes at 20 m above the bottom were 2.49 g m−2 d−1 and 20 mg C m−2 d−1, respectively. At the...
Tipo: Text
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00173/28380/26695.pdf
Imagem não selecionada

Imprime registro no formato completo
Different types of sediment gravity flows detected in the Var submarine canyon (northwestern Mediterranean Sea) ArchiMer
Khripounoff, Alexis; Crassous, Philippe; Lo Bue, N.; Dennielou, Bernard; Silva Jacinto, Ricardo.
Current velocities and vertical sediment fluxes in the Var submarine canyon were assessed at three stations respectively at 800 m, 1200 m and 1800 m depth, using moorings deployed for 4 months during winter 2008-2009. During this period, we observed three major sediment gravity flows, all characterized by sudden increases in current velocity that lasted 2-5 h and by downward particle fluxes. Each gravity flow, described using a high frequency current meter and two Acoustic Doppler Current Profiler (75 and 300 kHz ADCP) showed distinctive features. The first event, triggered during a flood of the Var River, was determined to be a hyperpycnal current with a large vertical extent (>100 m high) and relatively low velocity (40 cm s(-1)). The second event,...
Tipo: Text
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00113/22394/20343.pdf
Imagem não selecionada

Imprime registro no formato completo
Les apports organiques et leur transformation en milieu abyssal à l'interface eau-sédiment dans l'Océan Atlantique tropical ArchiMer
Khripounoff, Alexis; Rowe, Gilbert T.
Five particle traps were deployed at depths of 4 400 to 4 900 rn at two stations on the Demerara abyssal plain and one station on the Cape Verde abyssal plain (tropical Atlantic). At the same time, an intensive sampling of superficial sediments was carried out using a 0,25 m2 box corer. The total particle flux varied from 372 to 87,7 mg dry weightfm2/day. The average concentration of organic carbon was 40 mg/g of material collected. ln the surface sediment this was only 4 mg/g. A direct relationship existed between the intensity of the flux of organic matter and the richness of the organic matter of the deposited sediment. According to our calculations, more than 90% of the organic matter arriving at the bottom is consumed by the abyssal benthos and only...
Tipo: Text Palavras-chave: Milieu abyssal; Flux particulaire; Bilan d'énergie; Biochimie des particules et des sédiments; Atlantique tropical; Deep-sea; Particles flux; Tropical atlantic; Energy budget; Biochemitry of particles and sediments.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/00112/22318/19991.pdf
Imagem não selecionada

Imprime registro no formato completo
La nutrition d'echinodermes abyssaux I. Alimentation des holothuries ArchiMer
Khripounoff, Alexis; Sibuet, Myriam.
In deep waters, deposit-feeding holothurians represent a high percentage of the total abyssal biomass and play an important ecological role in sediment modification. The feeding of these organisms, which inhabit a nutritively poor environment, has been studied by means of analyses of intestinal contents. Four abundant species : Psychropotes longicauda Theel, Paroriza pallens (Koehler), Benthogone rosea Koehler and Molpadia blakei (Theel), collected between 2000 and 4500 m in the Bay of Biscay during three cruises organized by CNEXO-COB, were chosen for this study. The morphological characteristics of the ingested alimentary particles are described and the results of analyses of the organic matter in the guts reported. The species studied do not exhibit a...
Tipo: Text
Ano: 1980 URL: http://archimer.ifremer.fr/doc/1980/publication-5309.pdf
Imagem não selecionada

Imprime registro no formato completo
Direct observation of intense turbidity current activity in the Zaire submarine valley at 4000 m water depth ArchiMer
Khripounoff, Alexis; Vangriesheim, Annick; Babonneau, Nathalie; Crassous, Philippe; Dennielou, Bernard; Savoye, Bruno.
A large turbidity current was detected in the Zaire submarine valley at 4000 m water depth. Current meters, turbidimeter and sediment trap deployed on a mooring located in the channel axis, although they were damaged, recorded the signature of a very high energy event. An average velocity of more than 121 cm s-1 was measured 150 m above the channel floor. Coarse sand and plant debris were collected at 40 m height. The turbidity current clearly overflowed the edges of the valley as demonstrated by the large quantity of turbiditic material (464 mg organic carbon m-2 d-1) found in the sediment trap moored 13 km south from the channel axis.
Tipo: Text Palavras-chave: West equatorial Africa; Particle composition; Particle flux; Zaire channel; Turbidity current.
Ano: 2003 URL: http://archimer.ifremer.fr/doc/2003/publication-1419.pdf
Imagem não selecionada

Imprime registro no formato completo
High frequency of sediment gravity flow events in the Var submarine canyon (Mediterranean Sea) ArchiMer
Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Etoubleau, Joel.
This study aimed to analyze the role river floods play in triggering gravity flows and to investigate the role of submarine canyon systems as a conduit for terrigenous material to the deep sea. Two years of measurements in the Var canyon at depths ranging from 1200 m to 2350 m indicate that six floods of the Var River triggered hyperpycnal flows, an important mechanism for transporting particulate matter to the deep-sea floor. These sediment gravity flows were characterized by a sudden increase of current velocity that lasted 8 to 22 h and by downward particle fluxes that reached up to 600 g m(-2)d(-1) of particles and 3.1 g m(-2)d(-1) in terms of organic carbon. These large inputs of sediment and organic carbon may have a significant impact on deep-sea...
Tipo: Text Palavras-chave: West Mediterranean Sea; Particle flux; Var canyon; Hyperpycnal flow; Turbidity current.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6640.pdf
Imagem não selecionada

Imprime registro no formato completo
Particle flux in the Rainbow hydrothermal vent field (Mid-Atlantic Ridge): Dynamics, mineral and biological composition ArchiMer
Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Segonzac, Michel; Colaco, Ana; Desbruyeres, Daniel; Barthelemy, Roxane.
In order to provide information about the export and the distribution of hydrothermal particulate material to the surrounding deep ocean, four moorings were deployed in the vicinity of the hydrothermal Rainbow vent field (Mid-Atlantic Ridge, 36 degrees 14'N, 2250 m depth). The first mooring was a sediment trap with a current meter deployed at 2 m from a chimney of the Rainbow vent field and 1.5 m above the bottom (a.b.) for 16 days. It represented the reference for the initial composition of particles produced by the vent. The total mean mass particle flux (6.9 g m(-2) d(-1)) was distinctly higher than the flux measured at the shallower hydrothermal vents on the MAR segment. This particulate flux showed a high temporal variation at the scale of a few days...
Tipo: Text Palavras-chave: Zooplankton; Biochemistry; Geochemistry; Particle flux; Hydrothermal vent.
Ano: 2001 URL: https://archimer.ifremer.fr/doc/2001/publication-801.pdf
Imagem não selecionada

Imprime registro no formato completo
Temporal variation of currents, particulate flux and organism supply at two deep-sea hydrothermal fields of the Azores Triple Junction ArchiMer
Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Segonzac, Michel; Lafon, V; Waren, A.
In order to provide information on the production and the distribution of hydrothermal particulate and biological material produced by deep-sea hydrothermal vents, three moorings with sediment traps and currentmeters were deployed for one year in the Azores Triple Junction region. Two moorings were positioned close to two hydrothermal vent fields at the Mid-Atlantic Ridge (Rainbow, 36 degrees 14'N, 33 degrees 54'W, 2250 in depth and Lucky Strike 37 degrees 17'N, 32 degrees 17'W, 1600 in depth). A third was moored out of the influence of the Rainbow vents representing the reference of the pelagic flux in this area. At the Rainbow field, particulate flux (range 341-634 g m(-2)d(-1)) showed a high temporal variation controlled essentially by the current...
Tipo: Text Palavras-chave: Bivalve reproduction; Bivalve larvae; Particle composition; Particle flux; Currents; Deep sea hydrothermal vents.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-4059.pdf
Imagem não selecionada

Imprime registro no formato completo
Export of deep-sea hydrothermal particles, indigenous thermophilic microorganisms and larvae to the surrounding Ocean ArchiMer
Lesongeur, Francoise; Briand, Patrick; Godfroy, Anne; Crassous, Philippe; Byrne, Nathalie; Khripounoff, Alexis.
To assess the production and the export of particulate and biological material in deep-sea hydrothermal vents, four moorings with sediment traps and current meters were deployed for 24 days in the Azores Triple Junction (ATJ) region. They were deployed along an axis starting at the base of a hydrothermal vent chimney and ending 1000 m away. The particles sampled at the base of the chimney were characterized by high concentrations in total sulfur (16%) and iron (4%). The particle composition changed drastically with distance from the vent: the sulfur concentration decreased with an increase in clay components. Thermophilic microorganisms were successfully enriched from all the particle samples. Cultured strains were closely related to hydrothermal species,...
Tipo: Text Palavras-chave: Deep-sea hydrothermal vents; Particle flux; Hydrothermal microorganisms; Larvae; Regional index: North Atlantic; Mid-Atlantic Ridge; Azores Triple Junction.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00230/34111/33046.pdf
Imagem não selecionada

Imprime registro no formato completo
Anomalies of oxygen measurements performed with Aanderaa optodes ArchiMer
Lo Bue, N.; Vangriesheim, Annick; Khripounoff, Alexis; Soltwedel, T..
Four sets of measurements performed between 2005 and 2010 in the deep central Atlantic, the deep north-western Mediterranean Sea, and in the Arctic Ocean revealed strange anomalies in the performance of the Aanderaa optode 3830 sensors mounted on RCMI I current meters in low current regimes (current speeds > 10 cm s(-1)). All oxygen datasets collected during these deployments showed significant drops of oxygen (50-100 mu mol) affecting the data stability of the optode sensors in low hydrodynamic conditions. High correlations between all acquired parameters (temperature, turbidity, speed and direction of currents) verified that no unusual event occurred in the mooring areas during the periods of acquisition, although natural events responsible for such...
Tipo: Text
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00045/15584/14489.pdf
Registros recuperados: 39
Primeira ... 12 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional