Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation
International audience Riverine 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 de...
Published in: | Geophysical Research Letters |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2011
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Subjects: | |
Online Access: | https://insu.hal.science/insu-00645879 https://insu.hal.science/insu-00645879/document https://insu.hal.science/insu-00645879/file/GRL-Rouxel_al-2011.pdf https://doi.org/10.1029/2011GL048367 |
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ftinsu:oai:HAL:insu-00645879v1 |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
boreal forest glacier iron isotope nutrient speciation [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
boreal forest glacier iron isotope nutrient speciation [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDE.MCG]Environmental Sciences/Global Changes Schroth, Andrew, W. Crusius, J. Chever, Fanny Bostick, Benjamin, C. Rouxel, Olivier, J. Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
topic_facet |
boreal forest glacier iron isotope nutrient speciation [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience Riverine 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. |
author2 |
United States Geological Survey Reston (USGS) Coastal and Marine Geology Program University of Washington Seattle Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Université européenne de Bretagne - European University of Brittany (UEB) Lamont-Doherty Earth Observatory (LDEO) Columbia University New York Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Department of Marine Chemistry and Geochemistry (WHOI) Woods Hole Oceanographic Institution (WHOI) |
format |
Article in Journal/Newspaper |
author |
Schroth, Andrew, W. Crusius, J. Chever, Fanny Bostick, Benjamin, C. Rouxel, Olivier, J. |
author_facet |
Schroth, Andrew, W. Crusius, J. Chever, Fanny Bostick, Benjamin, C. Rouxel, Olivier, J. |
author_sort |
Schroth, Andrew, W. |
title |
Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
title_short |
Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
title_full |
Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
title_fullStr |
Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
title_full_unstemmed |
Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation |
title_sort |
glacial influence on the geochemistry of riverine iron fluxes to the gulf of alaska and effects of deglaciation |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://insu.hal.science/insu-00645879 https://insu.hal.science/insu-00645879/document https://insu.hal.science/insu-00645879/file/GRL-Rouxel_al-2011.pdf https://doi.org/10.1029/2011GL048367 |
geographic |
Gulf of Alaska |
geographic_facet |
Gulf of Alaska |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
ISSN: 0094-8276 EISSN: 1944-8007 Geophysical Research Letters https://insu.hal.science/insu-00645879 Geophysical Research Letters, 2011, 38, pp.L16605. ⟨10.1029/2011GL048367⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2011GL048367 insu-00645879 https://insu.hal.science/insu-00645879 https://insu.hal.science/insu-00645879/document https://insu.hal.science/insu-00645879/file/GRL-Rouxel_al-2011.pdf doi:10.1029/2011GL048367 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2011GL048367 |
container_title |
Geophysical Research Letters |
container_volume |
38 |
container_issue |
16 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1790600396820971520 |
spelling |
ftinsu:oai:HAL:insu-00645879v1 2024-02-11T10:03:59+01:00 Glacial influence on the geochemistry of riverine iron fluxes to the Gulf of Alaska and effects of deglaciation Schroth, Andrew, W. Crusius, J. Chever, Fanny Bostick, Benjamin, C. Rouxel, Olivier, J. United States Geological Survey Reston (USGS) Coastal and Marine Geology Program University of Washington Seattle Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Université européenne de Bretagne - European University of Brittany (UEB) Lamont-Doherty Earth Observatory (LDEO) Columbia University New York Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Department of Marine Chemistry and Geochemistry (WHOI) Woods Hole Oceanographic Institution (WHOI) 2011-08-25 https://insu.hal.science/insu-00645879 https://insu.hal.science/insu-00645879/document https://insu.hal.science/insu-00645879/file/GRL-Rouxel_al-2011.pdf https://doi.org/10.1029/2011GL048367 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2011GL048367 insu-00645879 https://insu.hal.science/insu-00645879 https://insu.hal.science/insu-00645879/document https://insu.hal.science/insu-00645879/file/GRL-Rouxel_al-2011.pdf doi:10.1029/2011GL048367 info:eu-repo/semantics/OpenAccess ISSN: 0094-8276 EISSN: 1944-8007 Geophysical Research Letters https://insu.hal.science/insu-00645879 Geophysical Research Letters, 2011, 38, pp.L16605. ⟨10.1029/2011GL048367⟩ boreal forest glacier iron isotope nutrient speciation [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2011 ftinsu https://doi.org/10.1029/2011GL048367 2024-01-24T17:23:53Z International audience Riverine 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. Article in Journal/Newspaper glacier Alaska Institut national des sciences de l'Univers: HAL-INSU Gulf of Alaska Geophysical Research Letters 38 16 n/a n/a |