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| Radford Knoery, Joel; German, C; Charlou, Jean-luc; Donval, Jean-pierre; Fouquet, Yves. |
| Through the deep ocean, hydrothermal plumes disperse high concentrations of key chemical tracers including He-3, CH4, Mn, Fe, H2S, etc. This paper focuses on the distribution and behavior of total dissolved sulfide (sulfide hereafter) in hydrothermal plumes to show that its plume concentration decreases to subnanomolar a few kilometers from the vents. We also report on sulfide removal rates determined at in situ conditions; we observe that they are two orders of magnitude greater than for open ocean seawater, consistent with sulfide being detected only in the vicinity of hydrothermal vents. From our observations, we infer that the sole presence of sulfide in hydrothermal plumes locates active venting at the kilometer scale. |
| Tipo: Text |
Palavras-chave: Chemical oceanography; Mid ocean ridges; Metals; Helium isotopes; Methane; Tracers; Hydrogen sulphide; Plumes; Hydrothermal activity. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-688.pdf |
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| Bouchet, Vincent; Debenay, Vincent; Sauriau, Pierre-guy; Radford Knoery, Joel; Soletchnik, Patrick. |
| Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. Foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic... |
| Tipo: Text |
Palavras-chave: Marennes Oléron bay; Aquaculture; Crassostrea gigas; Intertidal; Ammonium; Hypoxia; Organic matter; Living benthic foraminifera. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2586.pdf |
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