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Registros recuperados: 110 | |
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Naqvi,S.W.A. |
The Indian Ocean contains one of the oceans' most pronounced oxygen minimum zones (OMZ), which, anomalously, is the most intense in the northwestern sector (Arabian Sea). It also contains the majority of the area of oceanic continental margins in contact with oxygen-depleted waters. Impacts of the oxygen deficiency on regional biogeochemistry, especially anaerobic nitrogen transformations, are described. A comparison of the perennial, mesopelagic OMZ in the open Northwestern Indian Ocean is made with a shallower oxygen deficient system that develops seasonally (during late summer and autumn) over the western Indian shelf. The latter appears to have intensified in recent years presumably due to anthropogenic nutrient loading from land. |
Tipo: Journal article |
Palavras-chave: Indian Ocean; Nitrogen cycling; Denitrification; N2O; Eutrophication. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300011 |
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Bourget, J.; Zaragosi, S.; Garlan, T.; Gabelotaud, I.; Guyomard, P.; Dennielou, Bernard; Ellouz-zimmermann, N.; Schneider, J. L.. |
During the Fanindien 2006 cruise of R/V 'Beautemps-Beaupre', high resolution multibeam bathymetry, sub-bottom profiling and sediment coring was carried out along the East African margin, offshore Tanzania and Mozambique (Indian Ocean). The newly acquired data reveal the presence of a giant deep-sea valley (the Tanzania channel) that is more than 10 km wide at 4000 m water depth, along the continental rise. The valley remains similar to 70 m deep and 7 km wide at 800 km from the Tanzania coast. Morphological comparison with worldwide submarine channels show that the Tanzania channel is one of the largest known submarine valleys. This discovery brings new light on development of submarine valleys that drain sediments originated from the East African Rift... |
Tipo: Text |
Palavras-chave: Indian Ocean; East African margin; East African Rift System; Turbidite system; Submarine channel. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6855.pdf |
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Ronge, Thomas A.; Prange, M.; Mollenhauer, Gesine; Ellinghausen, Maret; Kuhn, G.; Tiedemann, R.. |
It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial‐interglacial atmospheric CO2‐levels. So far however, ventilation records from the Indian sector of the Southern Ocean, are widely missing. Here we present reconstructions of water residence times (depicted as ΔΔ14C and Δδ13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise (~570‐2500 m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep‐waters, we find two pulses of decreasing ΔΔ14C and δ13C values... |
Tipo: Text |
Palavras-chave: Radiocarbon; Ventilation; Southern Ocean; Younger Dryas; Carbon cycle; Indian Ocean. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72351/71258.pdf |
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Rodriguez, M.; Fournier, M.; Chamot-rooke, Nicolas; Huchon, P.; Bourget, Julien; Sorbier, M.; Zaragosi, S.; Rabaute, A.. |
The Owen Fracture Zone is a 800 km-long fault system that accommodates the dextral strike-slip motion between India and Arabia plates. Because of slow pelagic sedimentation rates that preserve the seafloor expression of the fault since the Early Pliocene, the fault is clearly observed on bathymetric data. It is made up of a series of fault segments separated by releasing and restraining bends, including a major pull-apart basin at latitude 20 degrees N. Some distal turbiditic channels from the Indus deep-sea fan overlap the fault system and are disturbed by its activity, thus providing landmarks to date successive stages of fault activity and structural evolution of the Owen Fracture Zone from Pliocene to Present. We determine the durability of relay... |
Tipo: Text |
Palavras-chave: Indian Ocean; Owen Fracture Zone; Pull-apart; Transform fault. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24426/22435.pdf |
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Mahe, Kelig; Evano, Hugues; Mille, Tiphaine; Bourjea, Jerome. |
Swordfish (Xiphias gladius) is an oceanic-pelagic species currently fully exploited by several fisheries in the Indian Ocean, with suspicion of overexploitation in the southwest, but without a clear understanding of the real stock structure within this Ocean. Population structure of the Indian stock was studied in the western Indian Ocean using 395 individual samples collected from 2009 to 2014. Sagittal otoliths of the fish have been removed and shape analysis performed on these calcified pieces. Otolith morphometrics data and normalized Elliptical Fourier Descriptors (EFDs) were then extracted automatically by the dedicated imageanalysis system TNPC. Preliminary, side effect was tested by Redundancy analysis (RDA) combined to permutation tests on 91... |
Tipo: Text |
Palavras-chave: Xiphias gladius; Otolith shape; Fourier descriptors; Stock discrimination; Indian Ocean. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00269/37980/36068.pdf |
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Bourget, J.; Zaragosi, S.; Garlan, T.; Gabelotaud, I.; Guyomard, P.; Dennielou, Bernard; Ellouz-zimmermann, N.; Schneider, J. L.. |
During the Fanindien 2006 cruise of R/V 'Beautemps-Beaupre', high resolution multibeam bathymetry, sub-bottom profiling and sediment coring was carried out along the East African margin, offshore Tanzania and Mozambique (Indian Ocean). The newly acquired data reveal the presence of a giant deep-sea valley (the Tanzania channel) that is more than 10 km wide at 4000 m water depth, along the continental rise. The valley remains similar to 70 m deep and 7 km wide at 800 km from the Tanzania coast. Morphological comparison with worldwide submarine channels show that the Tanzania channel is one of the largest known submarine valleys. This discovery brings new light on development of submarine valleys that drain sediments originated from the East African Rift... |
Tipo: Text |
Palavras-chave: Indian Ocean; East African margin; East African Rift System; Turbidite system; Submarine channel. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00324/43491/42958.pdf |
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Taquet, Marc; Sancho, G; Dagorn, L; Gaertner, J; Itano, D; Aumeeruddy, R; Wendling, B; Peignon, C. |
We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 +/- 2, mean +/- SD) in equatorial and 13 (10 +/- 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some... |
Tipo: Text |
Palavras-chave: Indian Ocean; Reunion Island; Seychelles; Fish aggregations; Visual census; Drifting FAD; Pelagic fishes. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3734.pdf |
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Quero, Jean-claude; Spitz, Jerome; Vayne, Jean-jacques. |
From the 8(th) to the 11(th) April 2007, at Reunion Island (Indian Ocean), some fish were collected at sea surface after the eruption of the Piton de la Fournaise. Among these were eleven specimens of Neocentropogon profundus (Scorpaenoidei: Tetrarogidae). Six species of this genus have been described: two from the Pacific Ocean, N. japonicus Matsubara, 1943 and N. trimaculatus Chan, 1966; four from the Indian Ocean, N. affinis (Lloyd, 1909) from the Gulf of Martaban, Myanmar, N. aeglefinus (Weber, 1913) from the Halmahera Sea, Timor Sea, probably a junior synonym of N. affinis, N. profundus (Smith, 1958) off Mozambique, and N. mesedai Klausewitz, 1985 from the Mismaris-Trough, Red Sea. The eleven specimens found at Reunion constitute the largest available... |
Tipo: Text |
Palavras-chave: Tetrarogidae; Neocentropogon profundus; Indian Ocean; Reunion Island; Volcanic eruption. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16051/13614.pdf |
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Setiawan, Riza Yuliratno; Mohtadi, Mahyar; Southon, John; Groeneveld, Jeroen; Steinke, Stephan; Hebbeln, Dierk. |
The advection of relatively fresh Java Sea water through the Sunda Strait is presently responsible for the low-salinity tongue in the eastern tropical Indian Ocean with salinities as low as 32. The evolution of the hydrologic conditions in the eastern tropical Indian Ocean since the last glacial period, when the Sunda shelf was exposed and any advection via the Sunda Strait was cutoff, and the degree to which these conditions were affected by the Sunda Strait opening are not known. Here we have analyzed two sediment cores (GeoB 10042-1 and GeoB 10043-3) collected from the eastern tropical Indian Ocean off the Sunda Strait that cover the past similar to 40,000years. We investigate the magnitude of terrigenous supply, sea surface temperature (SST), and... |
Tipo: Text |
Palavras-chave: Indian Ocean; Sunda Strait; Seawater oxygen isotopes; Java Sea; Sea surface temperatures; Terrigenous supply. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00496/60729/65238.pdf |
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Fontaine, Fabrice R.; Barruol, Guilhem; Tkalcic, Hrvoje; Woelbern, Ingo; Ruempker, Georg; Bodin, Thomas; Haugmard, Meric. |
The Piton de la Fournaise basaltic volcano, on La Réunion Island in the western Indian Ocean, is one of the most active volcanoes in the world. This volcano is classically considered as the surface expression of an upwelling mantle plume and its activity is continuously monitored, providing detailed information on its superficial dynamics and on the edifice structure. Deeper crustal and upper mantle structure under La Réunion Island is surprisingly poorly constrained, motivating this study. We used receiver function techniques to determine a shear wave velocity profile through the crust and uppermost mantle beneath La Réunion, but also at other seismic stations located on the hotspot track, to investigate the plume and lithosphere interaction and its... |
Tipo: Text |
Palavras-chave: Surface waves and free oscillations; Oceanic hotspots and intraplate volcanism; Hotspots; Crustal structure; Indian Ocean. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00287/39830/38352.pdf |
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Tedetti, Marc; Bigot, Lionel; Turquet, Jean; Guigue, Catherine; Ferretto, Nicolas; Goutx, Madeleine; Cuet, Pascale. |
We investigated the influence of freshwater discharges on biogeochemistry and benthic communities of La Saline fringing reef, the largest coral reef system of La Réunion Island (France, Indian Ocean). Sampling was conducted in February–March 2012 along a land-ocean continuum, including rivers, groundwater, reef waters, and oceanic waters. Our results indicated the discharges of basalt groundwater (enriched in nitrates) in the southern part of the reef, and the discharges of sand groundwater and river waters (enriched in organic matter) in sites located northward. These discharges mainly impacted fore reef surface waters, while groundwater resurgences were more diffuse and not clearly detected in depth. We highlighted the relationship Si(OH)4/NO3– to... |
Tipo: Text |
Palavras-chave: Coral reefs; La Reunion; Indian Ocean; Eutrophication; Groundwater; Nutrients; Organic matter; Fluorescence. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77030/78316.pdf |
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Taquet, Marc; Sancho, G; Dagorn, L; Gaertner, J; Itano, D; Aumeeruddy, R; Wendling, B; Peignon, C. |
We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 +/- 2, mean +/- SD) in equatorial and 13 (10 +/- 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some... |
Tipo: Text |
Palavras-chave: Indian Ocean; Reunion Island; Seychelles; Fish aggregations; Visual census; Drifting FAD; Pelagic fishes. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00602/71370/69818.pdf |
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Chambault, Philippine; Hattab, Tarek; Mouquet, Pascal; Bajjouk, Touria; Jean, Claire; Ballorain, Katia; Ciccione, Stéphane; Dalleau, Mayeul; Bourjea, Jerome. |
Despite the large number of species distribution modelling (SDM) applications driven by tracking data, individual information is most of the time neglected and traditional SDM approaches commonly focus on predicting the potential distribution at the species or population‐level. By running classical SDMs (population approach) with mixed models including a random factor to account for the variability attributable to individual (individual approach), we propose an innovative five‐steps framework to predict the potential and individual‐level distributions of mobile species using GPS data collected from green turtles. Pseudo‐absences were randomly generated following an environmentally‐stratified procedure. A negative exponential dispersal kernel was... |
Tipo: Text |
Palavras-chave: GPS tracking; Green turtles; Indian Ocean; Pseudo-absences; Shannon index; Spatial modelling. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79412/81963.pdf |
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Budziak, D; Schneider, Rr; Rostek, F; Muller, Pj; Bard, E; Wefer, G. |
We here present records of total organic carbon (TOC) and C-37 alkenones, used as indicators for past primary productivity, from the western (WAS) and eastern Arabian Sea (EAS). New data from an open ocean site of the WAS upwelling area are compared with similar records from Ocean Drilling Program (ODP) Site 723 from the continental margin off Oman and MD 900963 from the EAS. These records together with other proxies used to reconstruct upwelling intensity, indicate periods of high productivity in tune with precessional forcing. On the basis of their phase relationship to boreal summer insolation they can be divided into three groups: in the WAS differences between monsoonal proxies (1) and productivity (2) document a combined signal of moderate SW monsoon... |
Tipo: Text |
Palavras-chave: Indian Ocean; Marine organic chemistry; Upwelling and convergences. |
Ano: 2000 |
URL: https://archimer.ifremer.fr/doc/00220/33160/31672.pdf |
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Mazzullo, Alessandro; Stutzmann, Eleonore; Montagner, Jean-paul; Kiselev, Sergey; Maurya, Satish; Barruol, Guilhem; Sigloch, Karin. |
In the western Indian Ocean, the Reunion hot spot is one of the most active volcanoes on Earth. Temporal interactions between ridges and plumes have shaped the structure of the zone. This study investigates the mantle structure using data from the Reunion Hotspot and Upper Mantle-Reunions Unterer Mantel (RHUM-RUM) project, which significantly increased the seismic coverage of the western part of the Indian Ocean. For more than 1year, 57 ocean bottom seismometer stations and 23 temporary land stations were deployed over this area. For each earthquake station path, the Rayleigh wave fundamental mode phase velocities were measured for the periods from 30s to 300s and group velocities for the period from 16s to 250s. A three-dimensional model of the shear... |
Tipo: Text |
Palavras-chave: Tomography; Indian Ocean; Seismic anisotropy; Hot spot ridge; Upper mantle. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00600/71180/69533.pdf |
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Registros recuperados: 110 | |
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