Consulta: subjectFacets:"Particle flux"
Registros recuperados: 9
Data/hora: 09/06/2024 02:44:50

Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea
Provedor de dados: 5
Autores: Marty, J. C.; Goutx, M.; Guigue, C.; Leblond, N.; Raimbault, P.
Short-term changes in the flux of particulate matter were determined in the central north western Mediterranean Sea (near DYFAMED site) using drifting sediment traps at 200 m depth in the course of the DYNAPROC 2 cruise (14 September-17 October 2004). In this period of marked water column stratification, POC fluxes varied by an order of magnitude, in the range of 0.03-0.29 mgC m(-2) h(-1) over the month and showed very rapid and high variations. Particulate carbon export represented less than 5% of integrated primary production, suggesting that phytoplankton production was essentially sustained by internal recycling of organic matter and retained within the photic zone. While PON and POP fluxes paralleled one another, the elemental ratios POC/PON and...
Tipo: Text
Palavras-chave: Planktonic community structure; Flame ionization detection; Atlantic time series; Organic carbon flux; Deep ocean; Downward fluxes; Particle flux; Vertical flux; Lipid classes; Sargasso sea.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00210/32099/30556.pdf

Seasonal variations of downward particle fluxes in front of a reef pass (Moorea Island, French Polynesia)
Provedor de dados: 5
Autores: Schrimm, M; Heussner, S; Buscail, R.
Downward particle fluxes off the Taotoi Pass, a typical Polynesian lagoon pass, have been measured over an annual cycle by means of an array of three mooring lines deployed at 40 m depth on the external sandy plain seawards of the Tiahura reef. Each line was equipped with two hand-operated sediment traps located 1.5 and 10 m above the bottom. During the 1-year survey, the traps were deployed for seven periods of 2-3 weeks. One line equipped with an automated trap was further deployed at 400 m depth on the deep fore-reef slope to collect deep settling particles over two consecutive 6-month periods. For all periods investigated, fluxes on the external plain were highest in front of the pass, and decreased by half on either side (up- and downstream with...
Tipo: Text
Palavras-chave: Flux particulaire; Exportation de carbone; Récif corallien; Carbone organique; Carbonate; Particle flux; Carbon export; Coral reefs; Organic carbon; Carbonate.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00322/43320/42934.pdf

Export of deep-sea hydrothermal particles, indigenous thermophilic microorganisms and larvae to the surrounding Ocean
Provedor de dados: 5
Autores: 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

Hydrography and flow in the Lucky Strike segment of the Mid-Atlantic Ridge
Provedor de dados: 5
Autores: Thurnherr, A. M.; Reverdin, G; Bouruet Aubertot, P; Laurent, L; Vangriesheim, Annick; Ballu, V.
The Lucky Strike segment between 37 and 38N on the Mid-Atlantic Ridge is the focus of the international MoMAR program to monitor seafloor-spreading processes. During the GRAVILUCK cruise in August 2006, hydrographic, velocity and light-scattering data were collected in the rift valley at Lucky Strike in order to investigate the regional dynamics and to provide background information for the monitoring effort. The survey observations reveal a remarkably simple dynamical setting dominated by persistent northward flow transporting approximate to 0.2 Sv of water along the rift valley. Approximately half of this transport must upwell within a deep basin that occupies the northern half of the segment. In the comparatively shallow segment center, the along-valley...
Tipo: Text
Palavras-chave: Azores triple junction; Central north Atlantic; Hydrothermal vents; Particle flux; Rift valley; Heat flux; Water; Circulation; Currents; Fields.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4785.pdf

Particle flux in the Rainbow hydrothermal vent field (Mid-Atlantic Ridge): Dynamics, mineral and biological composition
Provedor de dados: 5
Autores: 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

High frequency of sediment gravity flow events in the Var submarine canyon (Mediterranean Sea)
Provedor de dados: 5
Autores: 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

Direct observation of intense turbidity current activity in the Zaire submarine valley at 4000 m water depth
Provedor de dados: 5
Autores: 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

Temporal variation of currents, particulate flux and organism supply at two deep-sea hydrothermal fields of the Azores Triple Junction
Provedor de dados: 5
Autores: 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

Particle Fluxes and Bulk Geochemical Characterization of the Cabo Frio Upwelling System in Southeastern Brazil: Sediment Trap Experiments between Spring 2010 and Summer 2012
Provedor de dados: 42
Autores: ALBUQUERQUE,ANA LUIZA S.; BELÉM,ANDRÉ L.; ZULUAGA,FRANCISCO J.B.; CORDEIRO,LIVIA G.M.; MENDOZA,URSULA; KNOPPERS,BASTIAAN A.; GURGEL,MARCIO H.C.; MEYERS,PHILIP A.; CAPILLA,RAMSÉS.
Physical and biogeochemical processes in continental shelves act synergistically in both transporting and transforming suspended material, and ocean dynamics control the dispersion of particles by the coastal zone and their subsequent mixing and dilution within the shelf area constrained by oceanic boundary currents, followed by their gradual settling in a complex sedimentary scenario. One of these regions is the Cabo Frio Upwelling System located in a significantly productive area of Southeastern Brazil, under the control of the nutrient-poor western boundary Brazil Current but also with a wind-driven coastal upwelling zone, inducing cold-water intrusions of South Atlantic Central Water on the shelf. To understand these synergic interactions among...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sediment traps; Bulk geochemical composition; Cabo Frio Upwelling System; Particle flux; Southeastern Brazilian shelf.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000200601