Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean (Articolo in rivista)

Type

• Prodotto della ricerca (Classe)
• Articolo in rivista (Classe)

Label

• Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean (Articolo in rivista) (literal)

Anno

• 2002-01-01T00:00:00+01:00 (literal)

Alternative label

• Frignani M.-1, Courp T.-2, Cochran J.K.-3, Hirshberg D.-3, Vitoria L.-2, Codina I.-2 (2002)
  Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean
  in Continental shelf research
  (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

• Frignani M.-1, Courp T.-2, Cochran J.K.-3, Hirshberg D.-3, Vitoria L.-2, Codina I.-2 (literal)

Pagina inizio

• 2175 (literal)

Pagina fine

• 2190 (literal)

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• Impact Factor: 1.495. The total number of citations for year 2002 was 2649 (literal)

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• 22 (literal)

Rivista

• Continental shelf research (Rivista)

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• In the open ocean, the most significant source of particles to surface waters is biological production, but on the continental margin the strong benthic–pelagic coupling that results from resuspension and lateral advection can permit sediments resuspended from the bottom to affect the entire water column and subsequently to be transported offshore. The short-lived natural radionuclide 234Th, produced in the water column from decay of its parent 238U, has proven to be a useful tracer for solute particle interactions, particle cycling and transport in the oceanic environment. Due to its short half-life, 234Th is a particularly sensitive tracer of scavenging and particle fluxes that change on a time scale of a few months. As part of the European programs EUROFLUXand EUROMARGE-NB,components of the Mediterranean Targeted Project(MTP-I), special attention was given to interactions between the water column and sediment and their effects on biogeochemical fluxes and material budgets on the North Balearic continental margin. In conclusion, our results indicate that the Lacaze-Duthiers canyon represents an environment in which the rates of scavenging are not appreciably different from those on the adjacent shelf, probably due to the similar scavenging capacities of the different particle assemblages. Instead our data suggest the importance of the canyon as a conduit for the cross-shelf transport of sediment and particle reactive chemicals. (literal)

Note

• ISI Web of Science (WOS) (literal)

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• 1- CNR, 2- Laboratoire de Sedimentologie et Geochimie Marines, Perpignan, France, 3 -Marine Sciences Research Center, SUNY. Stony Brook, NY, USA (literal)

Titolo

• Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean (literal)

Abstract

• To better understand the particle exchange processes across the Pyrenean continental margin, sampling was conducted in 1994 and 1995 at stations in and near the Lacaze-Duthiers canyon in the northwestern Mediterranean. Moored current meters provide evidence of water transport along the canyon axis (cross-slope) and along-slope with the prevailing regional circulation. Turbidity measurements show surficial nepheloid layers (SNL) roughly coincident with fluorescence resulting from biological productivity. Recurrent benthic nepheloid layers (BNL) (as observed at a station on the outer-shelf) are advected into the canyon, forming intermediate nepheloid layers (INL). The mineralogical composition of suspended particles collected at stations on the outer-shelf and head of the canyon indicates an illite and chlorite-rich assemblage with minor magnesian calcite, indicative of materials resuspended from the adjacent shelf sediments. The mineralogy of suspended particles at stations farther in the canyon shows the presence of material derived from the Rhone River and likely transported along-slope by the Liguro-Proven-cal current. Measurements of the short-lived naturally occurring radionuclide 234Th show that it is actively scavenged from the nepheloid layers. Within the canyon, scavenging (as indicated by the mean residence time of dissolved Th with respect to uptake onto particles) is similar in both the SNL (30–58 d) and INL (25–85 d). Residence times of particulate Th with respect to removal from the water column follow the same trends, with values of about 5 d (1994) and 12–19 d (1995) in the SNL and 11–20 d (1994) and 15–23 d (1995) in the INL. This research suggests that while the Lacaze-Duthiers canyon serves as a conduit through which sediment associated with nepheloid layers detached from the shelf are transported, the rates of scavenging of Th in the canyon are not appreciably different from those on the adjacent shelf. (literal)

Prodotto di

• Marine science institute (ISMAR) (Istituto)

Autore CNR

• MAURO FRIGNANI (Unità di personale interno)

Insieme di parole chiave

• Keywords of "Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean" (Insieme di parole chiave)

Incoming links:

Prodotto

• Marine science institute (ISMAR) (Istituto)

Autore CNR di

• MAURO FRIGNANI (Unità di personale interno)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi

• Continental shelf research (Rivista)

Insieme di parole chiave di

• Keywords of "Scavenging rates and particle characteristics in and near the Lacaze-Duthiers submarine canyon, northwest Mediterranean" (Insieme di parole chiave)