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| Closset, Ivia; Cardinal, Damien; Rembauville, Mathieu; Thil, Francois; Blain, Stephane. |
| A massive diatom-bloom is observed annually in the surface waters of the naturally Fe-fertilized Kerguelen Plateau (Southern Ocean). In this study, silicon isotopic signatures (δ30Si) of silicic acid (DSi) and suspended biogenic silica (BSi) were investigated in the whole water column with an unprecedented spatial resolution in this region, during the KEOPS-2 experiment (spring 2011). We use δ30Si measurements to track the silicon sources that fuel the bloom, and investigate the seasonal evolution of Si biogeochemical cycle in the iron fertilized area. We compare the results from a HNLC reference station with stations characterized by different degrees of iron enrichment and bloom conditions. Dissolved and particulate δ30Si signatures were generally highly... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00344/45528/45085.pdf |
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| Ardyna, Mathieu; Lacour, Léo; Sergi, Sara; D’ovidio, Francesco; Sallée, Jean-baptiste; Rembauville, Mathieu; Blain, Stéphane; Tagliabue, Alessandro; Schlitzer, Reiner; Jeandel, Catherine; Arrigo, Kevin Robert; Claustre, Hervé. |
| Hydrothermal activity is significant in regulating the dynamics of trace elements in the ocean. Biogeochemical models suggest that hydrothermal iron might play an important role in the iron-depleted Southern Ocean by enhancing the biological pump. However, the ability of this mechanism to affect large-scale biogeochemistry and the pathways by which hydrothermal iron reach the surface layer have not been observationally constrained. Here we present the first observational evidence of upwelled hydrothermally influenced deep waters stimulating massive phytoplankton blooms in the Southern Ocean. Captured by profiling floats, two blooms were observed in the vicinity of the Antarctic Circumpolar Current, downstream of active hydrothermal vents along the... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00501/61310/64869.pdf |
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