Consulta: subjectFacets:"Pb-210"
Registros recuperados: 5
Data/hora: 06/06/2024 00:53:02

Flux dynamics of planktic foraminiferal tests in the south-eastern Bay of Biscay (northeast Atlantic margin)
Provedor de dados: 5
Autores: Kuhnt, Tanja; Howa, Helene; Schmidt, Sabine; Marie, Louis; Schiebel, Ralf.
The temporal and water depth related dynamics of planktic foraminiferal fluxes in the south-eastern Bay of Biscay are discussed for a two year sampling period (June 2006-June 2008). Two sediment traps deployed at 800 m and 1700 m water depth at a mooring in 2000 m of water depth, were analyzed for the flux of planktic foraminiferal species &gt;150 mu m, in comparison with the total mass flux. Total flux of planktic foraminifera shows seasonal maxima in spring/early summer (&gt;2000 Ind.m(-2) d(-1)) and minima from late summer through winter (&lt;10 Ind.m(-2) d(-1)). The flux of planktic foraminiferal tests in the intermediate to deep water column at the inner Bay of Biscay comprises an intermittent and regionally variable signal of seasonal surface water...
Tipo: Text
Palavras-chave: Planktic foraminifera; Bay of Biscay; Sediment traps; Particulate mass flux; Pb-210; Seasonality; Lateral advection.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00125/23593/21785.pdf

Po-210 and Pb-210 in the tissues of the deep-sea hydrothermal vent mussel Bathymodiolus azoricus from the Menez Gwen field (Mid-Atlantic Ridge)
Provedor de dados: 5
Autores: Charmasson, Sabine; Le Faouder, Antoine; Loyen, Jeanne; Cosson, Richard P.; Sarradin, Pierre-marie.
The hydrothermal deep-sea vent fauna is naturally exposed to a highly specific environment enriched in potentially toxic species such as sulfides, metals and natural radionuclides due to the convective seawater circulation inside the oceanic crust and its interaction with basaltic or ultramafic host rocks. However, data on radionuclides in biota from such environment are very limited. An investigation was carried out on tissue partitioning of Po-210 and Pb-210, two natural radionuclides within the U-238 decay chain, in Bathymodiolus azoricus specimens from the Mid-Atlantic Ridge (Menez Gwen field). These two elements showed different distributions with high Pb-210 levels in gills and high Po-210 levels in both gills and especially in the remaining parts of...
Tipo: Text
Palavras-chave: Po-210; Pb-210; Radionuclide; Bathymodiolus; Bioaccumulation; Hydrothermal vent.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00030/14172/11864.pdf

210Po and 210Pb trophic transfer within the phytoplankton–zooplankton–anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea)
Provedor de dados: 5
Autores: Strady, Emilie; Harmelin-vivien, Mireille; Chiffoleau, Jean-francois; Veron, Alain; Tronczynski, Jacek; Radakovitch, Olivier.
The transfer of 210Po and 210Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of 210Po and 210Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on 210Po, 210Pb activity concentrations and 210Po/210Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is...
Tipo: Text
Palavras-chave: Po-210; Pb-210; Phytoplankton; Zooplankton; Pelagic fishes; Mediterranean Sea.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00255/36609/35264.pdf

Biotracers and geotracers of depositional events in NW Mediterranean margin over the past two centuries
Provedor de dados: 5
Autores: Giresse, P; Buscail, R; Charriere, B; Abassi, A; Masque, P; Sanchez-cabeza, Ja.
A detailed sedimentological and geochemical investigation was performed on slope sediments collected from the Gulf of Lions and Catalonian margins and from the northern Balearic margin. The study was based on cores, about 50 cm long. Various physiographic sites (canyons, open slopes) were selected according to the available sediment accumulation rates obtained with the Pb-210 geochronological method. At a short time scale, various parts of the slope were characterized by muddy hemipelagic sediment. Sedimentological data suggested that deposition was continuous. Total organic carbon and its hydrolysable fraction decreased downcore. Significant increase of C/N ratio downcore resulted from an early diagenetic process in response to the burial effect. However...
Tipo: Text
Palavras-chave: Méditerranée nord-occidentale; Vitesse de sédimentation; Processus gravitaires; Carbone organique; 210Pb; North-western Mediterranean; Sedimentation rate; Gravity-induced process; Organic carbon; Pb-210.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00322/43335/42892.pdf

Recent rates of carbon and nitrogen accumulation in peatlands of Isla Grande de Chiloé-Chile
Provedor de dados: 97
Autores: León,Carolina A; Olivan,Gisela.
BACKGROUND: Peatlands play a key role in the global carbon cycle; these contain one third of the world's soil organic carbon, equivalent to more than half the amount of carbon in the atmosphere. Nevertheless, these ecosystems have been scarcely studied in southern South America. The main objective of this paper is to evaluate the recent accumulation rates of carbon (C) and nitrogen (N) in two kinds of oligotrofic peatlands in Isla Grande de Chiloé (Chile). RESULTS: Using peat C and N content, dry bulk density, and Pb-210 dating, we determined the rates of N and C accumulation in profiles from five peatlands in the northern Chilean Patagonia. The recent rate of C accumulation (RERCA) ranges from 8.5 to 87.06 g C m-2 year-1, and the recent rate of N...
Tipo: Journal article
Palavras-chave: Carbon accumulation; Nitrogen accumulation; Northern Patagonia; Oligotrophic peatlands; Pb-210.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2014000100023