Consulta: subjectFacets:"Kerguelen"
Registros recuperados: 9
Data/hora: 09/06/2024 06:21:44

Polar Front around the Kerguelen Islands: An up-to-date determination and associated circulation of surface/subsurface waters
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Park, Young-hyang; Durand, Isabelle; Kestenare, Elodie; Rougier, Gilles; Zhou, Meng; D'Ovidio, Francesco; Cotte, Cedric; Lee, Jae-hak.
The circulation of iron-rich shelf waters around the Kerguelen Islands plays a crucial role for a climatically important, annually recurrent phytoplankton spring bloom over the sluggish shelf region and its downstream plume area along the Antarctic circumpolar flow. However, there is a long-standing confusion about the Polar Front (PF) in the Kerguelen region due to diverse suggestions in the literature for its geographical location with an extreme difference over 10° of latitude. Based on abundant historical hydrographic data, the in situ hydrographic and current measurements during the 2011 KEOPS2 cruise, satellite chlorophyll images, and altimetry-derived surface velocity fields, we determine and validate an up-to-date location of the PF around the...
Tipo: Text
Palavras-chave: Polar Front; Kerguelen; Southern Ocean.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00244/35485/33995.pdf

Deep structure of the northern Kerguelen Plateau and hotspot-related activity
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Charvis, P; Recq, M; Operto, S; Brefort, D.
Seismic refraction profiles were carried out in 1983 and 1987 throughout the Kerguelen Isles (southern Indian Ocean, Terres Australes and Antarctiques Francaises, TAAF) and thereafter at sea on the Kerguelen-Heard Plateau during the MD66/KeOBS cruise in 1991. These profiles substantiate the existence of oceanic-type crust beneath the Kerguelen-Heard Plateau stretching from 46 degrees S to 55 degrees S, including the archipelago. Seismic velocities within both structures are in the range of those encountered in 'standard' oceanic crust. However, the Kerguelen Isles and the Kerguelen-Heard Plateau differ strikingly in their velocity-depth structure. Unlike the Kerguelen Isles, the thickening of the crust below the Kerguelen-Heard Plateau is caused by a 17 km...
Tipo: Text
Palavras-chave: Hotspot; Kerguelen; Lower crust; Oceanic islands; Oceanic plateau; Underplating.
Ano: 1995
URL: https://archimer.ifremer.fr/doc/00297/40791/39809.pdf

Variations de la répartition des cachalots sur le plateau de Kerguelen suggérée par les données d’interaction avec les pêcheries
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Tixier, Paul; Welsford, Dirk; Lea, Mary-anne; Hindell, Mark; Guinet, Christophe; Janc, Anaïs; Richard, Gaetan; Gasco, Nicolas; Duhamel, Guy; Arangio, Rhys; Villanueva, Ching-maria; Suberg, Lavinia; Arnould, John.
The emergence of longline fishing for Patagonian toothfish (Dissostichus eleginoides) on the Kerguelen Plateau over the past two decades is concomitant with the development of depredation-type interactions by sperm whales (Physeter macrocephalus). Through a unique collaboration between the French and the Australian fisheries operating respectively around Kerguelen, and Heard Island and McDonald Islands (HIMI), this study preliminarily investigated the spatio–temporal variations of the rate of occurrence of sperm whale depredation on the Kerguelen Plateau. Between 2011 and 2016, sperm whales depredated toothfish on 29.1% of all longline sets and over 49.4% of the fished area. The probability of vessels to experience depredation decreased with the latitude...
Tipo: Text
Palavras-chave: Fisheries interactions; Sperm whale; Patagonian toothfish; Kerguelen; Depredation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00502/61411/65094.pdf

Origin of primitive ocean island basalts by crustal gabbro assimilation and multiple recharge of plume-derived melts
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Borisova, Anastassia Y.; Bohrson, Wendy A.; Gregoire, Michel.
Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine-hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open-system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy-constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21–19 Ma basaltic series, the most primitive series...
Tipo: Text
Palavras-chave: Ocean island basalt; Kerguelen; Mantle plume; Ocean metagabbro xenoliths; Crustal assimilation and fractional crystallization; Magma Chamber Simulator.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00393/50409/51128.pdf

Modéliser la réponse des espèces au changement climatique dans les iles subantarctiques : étude de cas chez les oursins du Plateau des Kerguelen
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Saucède, Thomas; Guillaumot, Charlène; Michel, Loic; Fabri-ruiz, Salomé; Bazin, Alexis; Cabessut, Marie; Garcia-berro, Aurora; Mateos, Amélie; Mathieu, Olivier; De Ridder, Chantal; Dubois, Philippe; Danis, Bruno; David, Bruno; Diaz, Angie; Lepoint, Gilles; Motreuil, Sébastien; Poulin, Elie; Féral, Jean-pierre.
In the Kerguelen Islands, the multiple effects of climate change are expected to impact coastal marine habitats. Species distribution models (SDM) can represent a convenient tool to predict the biogeographic response of species to climate change but biotic interactions are not considered in these models. Nevertheless, new species interactions can emerge in communities exposed to environmental changes and the structure of biotic interactions is directly related to the potential resilience of ecosystems. Trophic interaction studies can help predict species vulnerability to environmental changes using carbon (δ13C) and nitrogen (δ15N) stable isotope ratios to generate trophic models. Using new available data inputs, we generated robust SDM and trophic...
Tipo: Text
Palavras-chave: Fisheries interactions; Sperm whale; Patagonian toothfish; Kerguelen; Depredation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00592/70389/68471.pdf

Status and trends of albatrosses in the French Southern Territories, Western Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Weimerskirch, Henri; Delord, Karine; Barbraud, Christophe; Le Bouard, Fabrice; Ryan, Peter G.; Fretwell, Peter; Marteau, Cedric.
Today albatrosses are threatened worldwide, especially by fishing activities, and many populations are currently in decline. Albatrosses breeding at the French Southern Territories in the south-western Indian Ocean, on the Crozet, Kerguelen and Saint-Paul–Amsterdam island archipelagos, are monitored regularly. This monitoring has been based on a sample of species and sites, and there was a need for an assessment of the population trends for all species at each site. During the past 3 years most populations have been surveyed, allowing an assessment of the trends of albatrosses breeding at the archipelagos of the French Southern Territories over the past 40 years. Wandering Albatrosses show similar trends at all sites within the Crozet and Kerguelen...
Tipo: Text
Palavras-chave: Crozet; Kerguelen; Amsterdam; Fisheries; Monitoring.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00440/55192/83479.pdf

Decadal evolution of carbon sink within a strong bloom area in the subantarctic zone
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lourantou, Anna; Metzl, Nicolas.
The fate of the Southern Ocean atmospheric CO(2) sink is under question. Here we assess seasonal to decadal changes of surface fCO(2) within an extended sink area along the track between Kerguelen and Amsterdam islands in the subantarctic zone. Data from 17 oceanographic cruises were used, from 1991 to 2011 and two distinct regions were examined, separated by the Subantarctic Front (SAF). The region south of the SAF displays a strong summer phytoplankton bloom of up to -28 mmol C m(-2) d(-1) within a calm area, constrained by physics and topography. On an annual basis, this region is a 6-fold more important sink than that deduced from Takahashi climatology, highlighting the importance of key-areas separate examination before proceeding to spatial...
Tipo: Text
Palavras-chave: Kerguelen; Air-sea CO2 fluxes; Carbon cycle; Frontal region; Island mass effect; Subantarctic zone.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00144/25557/23706.pdf

Contribution of resuspended sedimentary particles to dissolved iron and manganese in the ocean: An experimental study
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cheize, Marie; Planquette, H.f.; Fitzsimmons, J.n.; Pelleter, Ewan; Sherrell, R.m.; Lambert, Christophe; Bucciarelli, E.; Sarthou, G.; Le Goff, Marion; Liorzou, Celine; Chéron, Sandrine; Viollier, E.; Gayet, Nicolas.
A number of trace metals play essential roles in marine ecosystem structure and biological productivity. Until recently, it has been argued that phytoplankton access primarily dissolved iron, while particulate iron was considered a refractory material with little use biologically and limited interaction with the dissolved pool. In order to assess the transfer mechanisms between sediment-sourced particulate trace metals and the dissolved pool, we conducted a 14-month incubation that reacted resuspended sediments with natural seawater, both originating from the Kerguelen area (KEOPS cruises; Southern Ocean), in the dark, and at concentrations replicating natural conditions. Three types of sediments were investigated (named BioSi, BioSi + Ca, and Basalt),...
Tipo: Text
Palavras-chave: Suspended particle dissolution; Sediment; Iron; Manganese; Biogenic silica; Southern Ocean; Kerguelen.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00460/57197/59166.pdf

Trace of the Kerguelen mantle plume: Evidence from seamounts between the Kerguelen Archipelago and Heard Island, Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Weis, D; Frey, Fa; Schlich, R; Schaming, M; Montigny, R; Damasceno, D; Mattielli, N; Nicolaysen, Ke; Scoates, Js.
The gravity and bathymetric highs on the Kerguelen Plateau in the southern Indian Ocean between the Kerguelen Archipelago and Heard Island are seamounts formed of Miocene alkalic basalts similar to those found on the islands. Dredging during the Kerimis survey cruise recovered &gt;1 ton of mostly basaltic rocks. One of the dredges (D6) yielded a large volume of in situ alkalic picritic pillow basalts, the first picritic lavas recovered that are related to the Kerguelen plume. K-Ar and Ar-40-Ar-39 ages are between 18 and 21 Ma for all but one sample, and these ages are only slightly younger than the main phase of volcanism on the archipelago. The dredged lavas form three distinct groups based on chemical and isotopic compositions. Incompatible element...
Tipo: Text
Palavras-chave: Kerguelen; Trace elements; Isotopes; Mantle plume; Hot spot track; Picrites; Geochemistry; 1025 Geochemistry : Composition of the mantle; 1040 Geochemistry : Isotopic composition/chemistry; 1065 Geochemistry : Trace elements (3670).
Ano: 2002
URL: https://archimer.ifremer.fr/doc/00223/33407/31856.pdf