GEOSCAN, résultats de la recherche


TitreEvidence for anthropogenic 14C-enrichment in estuarine waters adjacent to the North Sea
AuteurAhad, J M E; Ganeshram, R S; Spencer, R G M; Uher, G; Gulliver, P; Bryant, C L
SourceGeophysical Research Letters vol. 33, L08608, 2006., (Accès ouvert)
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110081
Documentpublication en série
Mediapapier; en ligne; numérique
Lat/Long OENS -2.0000 -1.0000 56.0000 54.5000
Sujetscarbone; teneurs en carbone; estuaires; dépôts estuairiens; études estuairiennes; milieu côtièr; études côtières; isotopes de carbone; isotopes; hydrogéologie; géologie marine
Résumé(disponible en anglais seulement)
The isotopic composition (d13C and D14C) of high molecular weight dissolved organic carbon (HMW DOC) was studied in the Tyne and Tweed estuaries, NE England. Despite significant removal of terrigenous HMW DOC in the low salinity regions (S < 15), D14C remained modern with little variation around 115%. This lack of apparent age discrimination was attributed to either non-oxidative removal or the absence of a significant proportion of old refractory C in the HMW DOC pool. At S > 15, we observed seaward increases in d13C and D14C. With no documented local 14C inputs, we attributed non-bomb related 14C-enrichment at S > 15 to a possible 'lingering effect' of distal anthropogenic sources in near-coastal North Sea HMW DOC. Given the global distribution of potential sources, we propose that anthropogenic 14C should be considered in assigning ages of DOC pools in near-coastal waters and suggest its possible use as a tracer for DOC transformations.