Consulta: subjectFacets:"Mid Atlantic Ridge"
Registros recuperados: 16
Data/hora: 16/06/2024 06:29:09

Review of the hydrothermal vent shrimp genus Mirocaris, redescription of M-fortunata and reassessment of the taxonomic status of the family Alvinocarididae (Crustacea : Decapoda : Caridea)
Provedor de dados: 5
Autores: Komai, T; Segonzac, Michel.
The hydrothermal vent shrimp genus Mirocaris is reviewed. Morphological comparison between the two nominal species in the genus, M. fortunata and M. keldyshi, was made based on the re-examination of the holotype and paratypes of Mirocarisfortunata and the paratypes of M. keldyshi. Samples newly collected from various sites on the Mid-Atlantic Ridge were also examined. The validity of the genus Mirocaris has been confirmed. However, our study has revealed that the supposed morphological characters distinguishing M. fortunata and M. keldyshi do not provide significant taxonomic differences and further comparison failed to detect morphological differences between the two taxa. Thus M. keldyshi is synonymized with M. fortunata, and so there is only one single...
Tipo: Text
Palavras-chave: Hydrothermalism; Mid Atlantic Ridge; Redescription; Synonym; Taxonomy; M. keldyshi; Mirocaris fortunata.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-883.pdf

A new deep-sea lobster of the genus Thymopides (Crustacea : Decapoda : Nephropidae) collected near the hydrothermal vent Snake Pit, Mid-Atlantic Ridge
Provedor de dados: 5
Autores: Segonzac, Michel; Macpherson, Enrique.
A second species of the genus Thymopides, T laurentae sp. nov., is described from a specimen trapped at 3505 m depth in the Mid-Atlantic Ridge, near the Snake Pit hydrothermal area. This new species is easily distinguishable from the type species T grobovi, collected off the subantarctic islands Heard and Kerguelen, at depth between 525 and 1220 m, by its smooth carapace, the abdomen without longitudinal median carina and the palm of the first pereopod distinctly longer than wide.
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Hydrothermal vent; Deep sea; Nephropidae; Thymopides.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-888.pdf

Preliminary biological characterization of the Saldanha hydrothermal field at the Mid-Atlantic Ridge (36 degrees 34 ' N, 32 degrees 26 ' W, 2200 m)
Provedor de dados: 5
Autores: Biscoito, M; Almeida, A; Segonzac, Michel.
A preliminary description of the biology of the Saldanha hydrothermal field in the Mid-Atlantic Ridge (36 degrees 34'N, 32 degrees 26'W, 2200 m) is given, based on direct observation, video images and samples. Venting occurs mainly in a diffuse way through sediment, but hydrothermal fluid discharges are visible through centimeter-long orifices, scattered on the sediment, over an area of approximately 400 m(2), at depths between 2,200 and 2,220 metres. Emitted fluids are transparent, with a temperature of 7-9 degrees C. An almost complete absence of macro- and megafauna around the venting orifices was found. The only vent invertebrate identified was the gastropod Phymorhynchus sp., with only two juvenile specimens caught. A careful examination of the images...
Tipo: Text
Palavras-chave: New records; Antimora; Acanthonus; Fish; Sponge; Bathyal megafauna; Gastropoda; Fauna assemblage; Mid Atlantic Ridge; Hydrothermal vents.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-3610.pdf

A new species of scale-worm (Polychaeta : Polynoidae), Lepidonotopodium jouinae sp nov., from the Azores Triple Junction on the Mid-Atlantic Ridge
Provedor de dados: 5
Autores: Desbruyeres, Daniel; Hourdez, Stéphane.
A new species of scale-worm, Lepidonotopodium jouinae, belonging to the sub-family Lepidonotopodinae (Polychaeta: Polynoidae) has been found in samples collected on deep-sea hydrothermal vent fields at the Azores Triple Junction on the Mid-Atlantic Ridge. It is the first species of Polynoidae described from the Mid-Atlantic Ridge hydrothermal vents. Other species of the same genus have been described from hydrothermal vents of the Pacific Ocean.
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Hydrothermal vent; Deep sea; Polynoidae; Polychaeta; Annelida.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-892.pdf

A new deep-sea genus of nannastacidae (Crustacea, cumacea) from the lucky strike hydrothermal vent field (Azores triple junction, mid-atlantic ridge)
Provedor de dados: 5
Autores: Corbera, J; Segonzac, Michel; Cunha, M.
A new cumacean genus and species, Thalycrocuma sarradini gen. et sp. nov., belonging to the family Nannastacidae is described from several sites of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37N, 1700 m depth). The new genus differs from others in the family by males lacking exopods on the pereopods 3 and 4 and having an antenna with a five-articulate peduncle and a short flagellum. This is the first cumacean species that could be considered, at the moment, as endemic from hydrothermal vent areas. Data on the accompanying fauna including other cumacean species (Cyclaspis longicaudata, Bathycuma brevirostre, Procampylaspis sp. and Makrokylindrus sp.) and some ecological remarks are included. A key for the currently known genera of the...
Tipo: Text
Palavras-chave: Systematics; Morphology; Mid Atlantic Ridge; Hydrothermal vents; Deep sea; Cumacea.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4358.pdf

Helium isotopes at the Rainbow hydrothermal site (Mid-Atlantic Ridge, 36 degrees 14 ' N)
Provedor de dados: 5
Autores: Jean Baptiste, Philippe; Fourre, Elise; Charlou, Jean-luc; German, Christopher; Radford Knoery, Joel.
The He-3/He-4 ratio and helium concentration have been measured in the vent fluids and the dispersing plume of the Rainbow hydrothermal site, on the Mid-Atlantic Ridge (MAR). The He-3/He-4 ratio (7.51 R-a) and He-3 end-member concentration (25 pmol/kg) are in the range of observed values elsewhere on mid-ocean ridges, pointing to the relative homogeneity of the upper mantle with respect to helium isotope geochemistry. He-3 is linearly correlated with methane and manganese throughout the plume, with CH4/He-3 and Mn/He-3 ratios identical to those measured in the hot fluids. The bulk residence time of the plume in the rift valley estimated from the plume He-3 budget is similar to20 days. The He-3 flux transported by the plume, calculated from current-meter...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Heat flux; Isotopes; Hydrothermal vents; Helium.
Ano: 2004
URL: https://archimer.ifremer.fr/doc/2004/publication-772.pdf

Mineralogy, geochemistry, and Nd isotope composition of the Rainbow hydrothermal field, Mid-Atlantic Ridge
Provedor de dados: 5
Autores: Marques, Ana Filipa A.; Barriga, F; Chavagnac, V; Fouquet, Yves.
Petrological, geochemical, and Nd isotopic analyses have been carried out on rock samples from the Rainbow vent field to assess the evolution of the hydrothermal system. The Rainbow vent field is an ultramafic-hosted hydrothermal system located on the Mid-Atlantic Ridge characterized by vigorous high-temperature venting (similar to 365 degrees C) and unique chemical composition of fluids: high chlorinity, low pH and very high Fe, and rare earth element (REE) contents (Douville et al., Chemical Geology 184:37-48, 2002). Serpentinization has occurred under a low-temperature (&lt; 270 degrees C) retrograde regime, later overprinted by a higher temperature sulfide mineralization event. Retrograde serpentinization reactions alone cannot reproduce the reported...
Tipo: Text
Palavras-chave: Rainbow vent field; Mid Atlantic Ridge; Nd isotope; Serpentinite; Massive sulphide.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1557.pdf

Are spatial variations in the diets of hydrothermal fauna linked to local environmental conditions?
Provedor de dados: 5
Autores: De Busserolles, F.; Sarrazin, Jozee; Gauthier, Olivier; Gelinas, Y.; Fabri, Marie-claire; Sarradin, Pierre-marie; Desbruyeres, Daniel.
Trophic relationships in Bathymodiolus azoricus mussel bed communities on the Tour Eiffel hydrothermal edifice (Lucky Strike) were assessed using delta C-13 and delta N-15 signatures from 14 hydrothermal species. The nutritional basis of B. azoricus was also investigated with delta S-34. Faunal samples and environmental data (temperature, pH, total dissolved sulfide, iron and copper concentrations) were collected from 12 different locations on the edifice. Chemical conditions varied between microhabitats, and were all correlated to temperature. Carbon and nitrogen isotopic results revealed the presence of two, apparently independent, trophic groups. The first was composed of symbiont-bearing fauna (B. azoricus and their associated polychaetes...
Tipo: Text
Palavras-chave: Lucky Strike (37 degrees 17.29 ' N 32 degrees 16.45 ' W); Mid Atlantic Ridge; Food webs; Hydrothermal springs; Environmental conditions; Stable isotopes.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7312.pdf

Processes Driving Iron and Manganese Dispersal From the TAG Hydrothermal Plume (Mid-Atlantic Ridge): Results From a GEOTRACES Process Study
Provedor de dados: 5
Autores: González-santana, David; Planquette, Helene; Cheize, Marie; Whitby, Hannah; Gourain, Arthur; Holmes, Thomas; Guyader, Vivien; Cathalot, Cecile; Pelleter, Ewan; Fouquet, Yves; Sarthou, Geraldine.
Hydrothermal vents are a recognized source of trace elements to the ocean inventory. Nevertheless, the contribution of slow-spreading ridges remains poorly resolved. To address this, high-resolution dissolved (&lt;0.45 μm) iron (dFe) and manganese (dMn) samples were collected during the GEOTRACES HERMINE GApr07 process study at the Mid Atlantic Ridge. Samples were collected at nine stations, from the TAG vent site to 75 km south-southwest following the neutrally buoyant plume. Concentrations of dMn and dFe ranged from 71 ± 6 and 51 ± 2 nmol kg–1 right above the vent site to 0.43 ± 0.01 and 1.56 ± 0.02 nmol kg–1 at the most distal station, respectively. Using a 5-box model coupled with our data, we show that as the plume traveled away from the vent,...
Tipo: Text
Palavras-chave: Iron; Manganese; Hydrothermal; TAG; Mid Atlantic Ridge; GEOTRACES.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75530/76431.pdf

Bioaccumulation of Hg, Cu, and Zn in the Azores triple junction hydrotherinal vent fields food web
Provedor de dados: 5
Autores: Colaco, Ana; Bustamante, Paco; Fouquet, Yves; Sarradin, Pierre-marie; Serrao Santos, R.
In this work, mercury (Hg), copper (Cu) and zinc (Zn) concentrations and tissue distribution are determined in seven benthic invertebrates species (the key species) from the Mid Atlantic Ridge (MAR) hydrothermal vent fields. The samples were collected from three hydrothermal vent fields - Menez Gwen, 840 m;, Lucky Strike, 1700 m and Rainbow, 2300 m - near the Azores Triple Junction. These fields are characterized by different depths, geological context and chemical composition of the hydrothermal fluid, particularly the metal content, which is reflected by the metal concentrations in the organisms. Indeed, our results show that organisms from Menez Gwen presented the highest Hg concentrations, while those from Lucky Strike and Rainbow were richer in Cu and...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Trophic relations; Trophic transfer; Biomagnification; Vent ecosystems; Heavy metals.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2305.pdf

Speciation of dissolved copper within an active hydrothermal edifice on the Lucky Strike vent field (MAR, 37 degrees N)
Provedor de dados: 5
Autores: Sarradin, Pierre-marie; Waeles, M; Bernagout, Solene; Le Gall, Christian; Sarrazin, Jozee; Riso, R.
The objective of this study was to deter-mine the concentrations of different fractions of dissolved copper (after filtration at 0.45 mu m) along the cold part of the hydrothermal fluid-seawater mixing zone on the Tour Eiffel edifice (MAR). Dissolved copper was analyzed by stripping chronopotentiometry (SCP) after chromatographic C-18 extraction. Levels of total dissolved copper (0.03 to 5.15 mu M) are much higher than those reported for deep-sea oceanic waters but in accordance with data previously obtained in this area. Speciation measurements show that the hydrophobic organic fraction (C18Cu) is very low (2 +/- 1%). Dissolved copper is present mainly as inorganic and hydrophilic organic complexes (nonC(18)CU). The distribution of copper along the pH...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Hydrothermal vent; Speciation; Dissolved copper.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-5301.pdf

Recent volcanic events and the distribution of hydrothermal venting at the Lucky Strike hydrothermal field, Mid-Atlantic Ridge
Provedor de dados: 5
Autores: Ondreas, Helene; Cannat, M.; Fouquet, Yves; Normand, Alain; Sarradin, Pierre-marie; Sarrazin, Jozee.
We present new high-resolution bathymetry and backscatter data acquired in 2006 with the ROV Victor 6000 over the Lucky Strike hydrothermal field, Mid-Atlantic Ridge. As long-term monitoring of the Lucky Strike area (MoMAR project) is being implemented, these new high-resolution data offer an unprecedented view of the distribution of hydrothermal edifices, eruptive facies, and small-scale tectonic features in the Lucky Strike vent field. We show that vents located in the NW and NE correspond with wide expanses of lumpy seafloor which we interpret as primarily made of broken chimneys and sulfide edifices. They are found above scarps with relief &gt; 50 m or on associated mass wasting deposits. By contrast, the SE and SW vents correspond with small expanses...
Tipo: Text
Palavras-chave: Hydrothermalism; Lava lake; Lucky Strike; Mid Atlantic Ridge.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6161.pdf

Interactions of deep-sea vent invertebrates with their environment: The case of Rimicaris exoculata
Provedor de dados: 5
Autores: Schmidt, Caroline; Le Bris, Nadine; Gaill, F.
The vent shrimp Rimicaris exoculata thrives around many hydrothermal vent sites along the Mid-Atlantic Ridge (MAR), where it aggregates into dense swarms. In contrast to hydrothermal vent fields at the East Pacific Rise (EPR), where the biomass is dominated by tubeworms, clams, and mussels, this shrimp is one of the major animal species at MAR vents. These animals are found in the dynamic mixing interface between cold oxygenated seawater and hot, reduced hydrothermal vent fluid. The adaptation of this shrimp to the hostile deep-sea hydrothermal environment and its survival strategy has been investigated since their discovery at the TAG site in the late 1980s. Rimicaris exoculata is now known to colonize black smoker complexes along the MAR in the...
Tipo: Text
Palavras-chave: Extreme environments; Microorganisms; Chemosynthesis; Biomineralization; Symbiosis; Deep sea; Hydrothermal vents; Mid Atlantic Ridge; Shrimp.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3925.pdf

Evidence of a recent magma dike intrusion at the slow spreading Lucky Strike segment, Mid-Atlantic Ridge - art. no. B12102
Provedor de dados: 5
Autores: Dziak, Rp; Smith, Dk; Bohnenstiehl, Dr; Fox, Cg; Desbruyeres, Daniel; Matsumoto, H; Tolstoy, M; Fornari, Dj.
[1] Mid-ocean ridge volcanic activity is the fundamental process for creation of ocean crust, yet the dynamics of magma emplacement along the slow spreading Mid-Atlantic Ridge ( MAR) are largely unknown. We present acoustical, seismological, and biological evidence of a magmatic dike intrusion at the Lucky Strike segment, the first detected from the deeper sections (&gt; 1500 m) of the MAR. The dike caused the largest teleseismic earthquake swarm recorded at Lucky Strike in &gt; 20 years of seismic monitoring, and one of the largest ever recorded on the northern MAR. Hydrophone records indicate that the rate of earthquake activity decays in a nontectonic manner and that the onset of the swarm was accompanied by 30 min of broadband (&gt; 3 Hz) intrusion...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Earthquake; Hydroacoustic.
Ano: 2004
URL: https://archimer.ifremer.fr/doc/00000/10897/7768.pdf

Distribution and spatial variation of hydrothermal faunal assemblages at Lucky Strike (Mid-Atlantic Ridge) revealed by high-resolution video image analysis
Provedor de dados: 5
Autores: Cuvelier, Daphne; Sarrazin, Jozee; Colaco, Ana; Copley, Jon; Desbruyeres, Daniel; Glover, Adrian G.; Tyler, Paul; Santos, Ricardo Serrao.
Whilst the fauna inhabiting hydrothermal vent structures in the Atlantic Ocean is reasonably well known, less is understood about the spatial distributions of the fauna in relation to abiotic and biotic factors. In this study, a major active hydrothermal edifice (Eiffel Tower, at 1690 m depth) on the Lucky Strike vent field (Mid-Atlantic Ridge (MAR)) was investigated. Video transects were carried out by ROV Victor 6000 and complete image coverage was acquired. Four distinct assemblages, ranging from dense larger-sized Bathymodiolus mussel beds to smaller-sized mussel clumps and alvinocaridid shrimps, and two types of substrata were defined based on high definition photographs and video imagery. To evaluate spatial variation, faunal distribution was mapped...
Tipo: Text
Palavras-chave: Vent ecology; Mid Atlantic Ridge; Hydrothermal vent; Lucky Strike; Video analysis; Faunal assemblages; Spatial distribution; Community structure.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7328.pdf

Polar lipid fatty acids as indicators of trophic associations in a deep-sea vent system community
Provedor de dados: 5
Autores: Colaco, Ana; Desbruyeres, Daniel; Guezennec, Jean.
The polar lipid fatty acid (PLFA) profiles of invertebrates living in chemosynthetic communities can indicate the degree to which these animals depend on specific types of bacteria. To identify the nutritional sources of various species from deep-sea hydrothermal vents of the Mid-Atlantic Ridge, a Principal Component Analysis was performed using individual PLFA profiles as descriptors. Two associations representing different feeding groups were identified: (i) mussels, commensal polychaetes and gastropods, (ii) shrimps and crabs. The first association relies more on sulphide-oxidizing bacteria, while the second one has more anaerobic sulphate-reducing bacteria biomarkers. Other small invertebrates reveal different diets. The polychaete Amathys lutzi shows...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Biomarkers; Hydrothermal vents; Fatty acids.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2538.pdf