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dc.contributor.authorSchroth, Andrew W.  Concept link
dc.contributor.authorCrusius, John  Concept link
dc.contributor.authorChever, Fanny  Concept link
dc.contributor.authorBostick, Benjamin C.  Concept link
dc.contributor.authorRouxel, Olivier J.  Concept link
dc.date.accessioned2011-09-19T19:06:32Z
dc.date.available2011-09-19T19:06:32Z
dc.date.issued2011-08-25
dc.identifier.citationGeophysical Research Letters 38 (2011): L16605en_US
dc.identifier.urihttps://hdl.handle.net/1912/4817
dc.descriptionThis paper is not subject to U.S. copyright. The definitive version was published in Geophysical Research Letters 38 (2011): L16605, doi:10.1029/2011GL048367.en_US
dc.description.abstractRiverine iron (Fe) derived from glacial weathering is a critical micronutrient source to ecosystems of the Gulf of Alaska (GoA). Here we demonstrate that the source and chemical nature of riverine Fe input to the GoA could change dramatically due to the widespread watershed deglaciation that is underway. We examine Fe size partitioning, speciation, and isotopic composition in tributaries of the Copper River which exemplify a long-term GoA watershed evolution from one strongly influenced by glacial weathering to a boreal-forested watershed. Iron fluxes from glacierized tributaries bear high suspended sediment and colloidal Fe loads of mixed valence silicate species, with low concentrations of dissolved Fe and dissolved organic carbon (DOC). Iron isotopic composition is indicative of mechanical weathering as the Fe source. Conversely, Fe fluxes from boreal-forested systems have higher dissolved Fe concentrations corresponding to higher DOC concentrations. Iron colloids and suspended sediment consist of Fe (hydr)oxides and organic complexes. These watersheds have an iron isotopic composition indicative of an internal chemical processing source. We predict that as the GoA watershed evolves due to deglaciation, so will the source, flux, and chemical nature of riverine Fe loads, which could have significant ramifications for Alaskan marine and freshwater ecosystems.en_US
dc.description.sponsorshipWe appreciate support from the USGS CMGP, NCCWSC, and the Mendenhall Postdoctoral Program.en_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/msword
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dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2011GL048367
dc.subjectBoreal foresten_US
dc.subjectGlacieren_US
dc.subjectIronen_US
dc.subjectIsotopeen_US
dc.subjectNutrienten_US
dc.subjectSpeciationen_US
dc.titleGlacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciationen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2011GL048367


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