DOI: 10.1002/2014GB004928
Scopus记录号: 2-s2.0-84910136006
论文题名: Iron sources and dissolved-particulate interactions in the seawater of the Western Equatorial Pacific, iron isotope perspectives
作者: Labatut M ; , Lacan F ; , Pradoux C ; , Chmeleff J ; , Radic A ; , Murray J ; W ; , Poitrasson F ; , Johansen A ; M ; , Thil F
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2014
卷: 28, 期: 10 起始页码: 1044
结束页码: 1065
语种: 英语
英文关键词: equatorial Pacific
; GEOTRACES
; iron isotopes
; Papua New Guinea
; particles
; seawater
Scopus关键词: aerosol
; dissolution
; iron
; isotopic composition
; marine sediment
; runoff
; seawater
; sediment chemistry
; source-sink dynamics
; Bismarck Archipelago
; New Britain
; New Guinea
; New Ireland [(PRV) Papua New Guinea]
; Pacific Ocean
; Pacific Ocean (Equatorial)
; Papua New Guinea
; Rabaul Caldera
; Sepik River
英文摘要: This work presents iron isotope data in the western equatorial Pacific. Marine aerosols and top core margin sediments display a slightly heavy Fe isotopic composition (δ56Fe) of 0.33 ± 0.11‰ (2SD) and 0.14 ± 0.07‰, respectively. Samples reflecting the influence of Papua New Guinea runoff (Sepik River and Rabaul volcano water) are characterized by crustal values. In seawater, Fe is mainly supplied in the particulate form and is found with a δ56Fe between -0.49 and 0.34 ± 0.07‰. The particulate Fe seems to be brought mainly by runoff and transported across continental shelves and slopes. Aerosols are suspected to enrich the surface Vitiaz Strait waters, while hydrothermal activity likely enriched New Ireland waters. Dissolved Fe isotopic ratios are found between -0.03 and 0.53 ± 0.07‰. They are almost systematically heavier than the corresponding particulate Fe, and the difference between the signature of both phases is similar for most samples with Δ56FeDFe - PFe = +0.27 ± 0.25‰ (2SD). This is interpreted as an equilibrium isotopic fractionation revealing exchange fluxes between both phases. The dissolved phase being heavier than the particles suggests that the exchanges result in a net nonreductive release of dissolved Fe. This process seems to be locally significantly more intense than Fe reductive dissolution documented along reducing margins. It may therefore constitute a very significant iron source to the ocean, thereby influencing the actual estimation of the iron residence time and sinks. The underlying processes could also apply to other elements. Key Points Isotopic composition of dissolved and particulate Fe in seawaterIsotopic composition of Fe in marine aerosol, Sepik, and margin sedimentsNonreductive release would be an important source of dissolved Fe © 2014. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77511
Appears in Collections: 气候变化事实与影响
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作者单位: Laboratoire des Etudes en Géophysique et Océanographie Spatiale, Observatoire Midi-Pyrénées, CNES/CNRS/IRD/University of Toulouse, France; Laboratoire Géosciences Environnement Toulouse, Observatoire Midi-Pyrénées, CNRS/IRD/University of Toulouse, France; School of Oceanography, University of Washington, Seattle, WA, United States; Central Washington University, Elensburg, WA, United States; Laboratoire des Sciences du Climat et de l'Environnement, CNRS/CEA/UVSQ, Gif-sur-Yvette, France
Recommended Citation:
Labatut M,, Lacan F,, Pradoux C,et al. Iron sources and dissolved-particulate interactions in the seawater of the Western Equatorial Pacific, iron isotope perspectives[J]. Global Biogeochemical Cycles,2014-01-01,28(10)