| Registro completo |
| Provedor de dados: |
5
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| País: |
France
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| Título: |
Drastic changes in deep-sea sediment porewater composition induced by episodic input of organic matter
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| Autores: |
Gehlen, Marion
Rabouille, Christophe
Ezat, Ullah
Guidi-guivard, Laurence D.
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| Data: |
1997-07
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| Ano: |
1997
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| Resumo: |
We report the first seasonal time-series observations of porewater composition obtained for deep-sea sediments. We observed considerable temporal variability of O-2, NO3-, and Mn2+ profiles at the French JGOFS site DYFAMED (western Mediterranean) in response to a pulsed input of organic matter. A delivery of reactive organic matter representing only 1% of the average organic C content of surface sediments (0.6% wt/wt) was required in order to fuel the observed changes in porewater composition. The perturbation resulted in dramatic changes in integrated reaction rates and sediment-water fluxes. O-2 uptake rates increased from 1.26 to 1.82 mmol m(-2) d(-1), while nitrification rates rose from 0.13 to 0.18 mmol m(-2) d(-1). These changes were paralleled by a decrease in NO3- effluxes across the sediment-water interface from 0.07 to 0.01 mmol m(-2) d(-1) and a concomitant rise of denitrification rates from 0.06 to 0.17 mmol m(-2) d(-1). Porewater profiles responded rapidly to the sediment pulse deposition, returning to their steady-state values within a few months. The main driving force appeared not to be the seasonal variability of pelagic production but rather the downslope transport of resuspended upper-shelf sediments.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00240/35110/33606.pdf
https://archimer.ifremer.fr/doc/00240/35110/
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| Editor: |
Amer Soc Limnology Oceanography
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| Formato: |
application/pdf
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| Fonte: |
Limnology And Oceanography (0024-3590) (Amer Soc Limnology Oceanography), 1997-07 , Vol. 42 , N. 5 , P. 980-986
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| Direitos: |
1997, by the American Society of Limnology and Oceanography, Inc
info:eu-repo/semantics/openAccess
restricted use
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