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| Arraes-mescoff, R; Roy-barman, M; Coppola, L; Souhaut, M; Tachikawa, K; Jeandel, C; Sempere, R; Yoro, C. |
| m) concentrations of Al, Sr, Ba, Mn, Rare Earth Elements (REE) and Th isotopes were determined over time. We obtain percentages of dissolution in agreement with the general knowledge about the solubility of these tracers: Th approximate to Al < Heavy REE < Light REE < Mn < Ba < Sr. For Mn and Ce, precipitation/adsorption occurs at the end of the experiment probably due to their oxidation as insoluble oxides. Particulate residence time of the tracers ranged from less than 1 day to 10-14 days. During the experiment, biological activity has a control on the dissolution process through the remineralization of particulate organic carbon, In the 30 m experiment, the observed dissolution of aragonite indicates that the pH of the incubation solution... |
| Tipo: Text |
Palavras-chave: Marine particles; Dissolution; Trace elements; Thorium isotopes; Western Mediterranean Sea. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00300/41128/40316.pdf |
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| Bianchi, A; Calafat, A; De Wit, R; Garcin, J; Tholosan, O; Cacho, I; Canals, M; Fabres, J; Grout, H; Masque, P; Sanchez-cabeza, Ja; Sempere, R. |
| Microbiological and biogeochemical studies were carried out in sediments and near bottom waters in the upwelling area off the Malaga coast and in the Almeria-Oran frontal zone. In these nutrient-rich conditions, metabolic activity is potentially limited by oxygen availability through the sediment depth. In the surficial sediments of the frontal zone, however, oxygen penetrated to a depth of 4 cm, allowing oxic mineralisation processes to occur throughout the layer. In the surficial sediments of the upwelling area, oxygen penetration was limited to the top 2.5 cm, leading to anoxic conditions. Glutamate respiration and global oxygen uptake rates were clearly higher than in the frontal zone. In the superficial sediments of the frontal zone, bacteria were... |
| Tipo: Text |
Palavras-chave: Taux de minéralisation; Sédiments; Eaux profondes; Méditerranée occidentale; Bacteria; Mineralisation rate; Sediments; Deep-sea; Western Mediterranean. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00322/43298/43034.pdf |
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| Naudin, Jj; Cauwet, G; Leveau, M; Lochet, F; Pauc, H; Romano, Jc; Sempere, R. |
| Particulate matter from the bottom nepheloid layer, off the Rhone river mouth was sampled with a newly-designed frame code-named SYMPHY. Several spreading phases of the Rhodanian suspensions on the continental shelf were evidenced by currentmeter records, particulate matter analyses, CTD and nephelometric measurements. These data permitted the study of the mechanisms which control the aging of the suspensions during their transfer to a sea with very small amplitude tides. The bottom nepheloid layer can be defined as a vertical concentration gradient resulting from an equilibrium between the horizontal (Rhodanian inputs) and the vertical (surface nepheloid layer) components of the particulate flux. The variability of this equilibrium, controlled by... |
| Tipo: Text |
Palavras-chave: BOTTOM NEPHELOID LAYER; PARTICULATE MATTER; CURRENT MEASUREMENTS; HYDROLOGY. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00101/21230/18847.pdf |
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