Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows
Glaciers can be a significant and locally dominant source of iron (Fe), a biologically essential micronutrient, in high latitude coastal seas. The vast majority of this glacial Fe delivery is associated with particles, yet the speciation of the solid-phase Fe and specifically the relationships that...
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ftnioz:oai:imis.nioz.nl:347130 2023-05-15T13:21:42+02:00 Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows van Genuchten, C.M. Rosing, M.T. Hopwood, M.J. Liu, T. Krause, J. Meire, L. 2021 application/pdf https://www.vliz.be/imisdocs/publications/80/369180.pdf en eng info:eu-repo/semantics/altIdentifier/wos/000709450900020 info:eu-repo/semantics/altIdentifier/doi/doi.org/10.1016/j.epsl.2021.117234 https://www.vliz.be/imisdocs/publications/80/369180.pdf info:eu-repo/semantics/openAccess %3Ci%3EEarth+Planet.+Sci.+Lett.+576%3C%2Fi%3E%3A+117234.+%3Ca+href%3D%22https%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2021.117234%22+target%3D%22_blank%22%3Ehttps%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2021.117234%3C%2Fa%3E info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftnioz https://doi.org/10.1016/j.epsl.2021.117234 2023-02-22T23:20:20Z Glaciers can be a significant and locally dominant source of iron (Fe), a biologically essential micronutrient, in high latitude coastal seas. The vast majority of this glacial Fe delivery is associated with particles, yet the speciation of the solid-phase Fe and specifically the relationships that govern exchange between particulate and dissolved Fe phases in these environments are poorly described. In this work, we performed measurements of in situ dissolved Fe (dFe) along meltwater and particle plumes in three transects around Disko Bay and Ameralik Fjord (West Greenland). Measurements of dFe were combined with Fe K-edge X-ray absorption spectroscopy analysis of ∼40 suspended sediment samples obtained from the same transects and from select depth profiles down to 300 m. We observed relatively constant dFe levels (4 to 10 nM for nearly all dFe measurements) across fjords with widely varying particulate Fe(II) contents (from 20 to 90% Fe(II)), indicating that dFe concentrations had little dependence on the oxidation state of Fe in the suspended sediment. Particulate Fe data were grouped by underlying bedrock geology, with suspended sediment consisting of 80-90% biotite-like Fe(II) in fjords with Precambrian shield geology and poorly-ordered Fe(III) particles (<20-30% Fe(II)) in one fjord with suspended sediments derived from tertiary basalts. Our characterization data indicated no significant change in the average Fe oxidation state and bonding environment of particles along the fjord transects, implying that Fe(II) in biotite-like coordination is not a readily labile Fe form on this spatial scale. Our results suggest that dFe in these glacially-modified coastal waters is buffered at a relatively constant low nM concentration due to factors other than particle Fe mineralogy and that glacier-derived Fe phases are relatively inert on this spatial scale. Article in Journal/Newspaper Ameralik Ameralik fjord Disko Bay glacier Greenland greenlandic NIOZ Repository (Royal Netherlands Institute for Sea Research) Ameralik ENVELOPE(-51.000,-51.000,64.117,64.117) Greenland Earth and Planetary Science Letters 576 117234 |
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Open Polar |
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NIOZ Repository (Royal Netherlands Institute for Sea Research) |
op_collection_id |
ftnioz |
language |
English |
description |
Glaciers can be a significant and locally dominant source of iron (Fe), a biologically essential micronutrient, in high latitude coastal seas. The vast majority of this glacial Fe delivery is associated with particles, yet the speciation of the solid-phase Fe and specifically the relationships that govern exchange between particulate and dissolved Fe phases in these environments are poorly described. In this work, we performed measurements of in situ dissolved Fe (dFe) along meltwater and particle plumes in three transects around Disko Bay and Ameralik Fjord (West Greenland). Measurements of dFe were combined with Fe K-edge X-ray absorption spectroscopy analysis of ∼40 suspended sediment samples obtained from the same transects and from select depth profiles down to 300 m. We observed relatively constant dFe levels (4 to 10 nM for nearly all dFe measurements) across fjords with widely varying particulate Fe(II) contents (from 20 to 90% Fe(II)), indicating that dFe concentrations had little dependence on the oxidation state of Fe in the suspended sediment. Particulate Fe data were grouped by underlying bedrock geology, with suspended sediment consisting of 80-90% biotite-like Fe(II) in fjords with Precambrian shield geology and poorly-ordered Fe(III) particles (<20-30% Fe(II)) in one fjord with suspended sediments derived from tertiary basalts. Our characterization data indicated no significant change in the average Fe oxidation state and bonding environment of particles along the fjord transects, implying that Fe(II) in biotite-like coordination is not a readily labile Fe form on this spatial scale. Our results suggest that dFe in these glacially-modified coastal waters is buffered at a relatively constant low nM concentration due to factors other than particle Fe mineralogy and that glacier-derived Fe phases are relatively inert on this spatial scale. |
format |
Article in Journal/Newspaper |
author |
van Genuchten, C.M. Rosing, M.T. Hopwood, M.J. Liu, T. Krause, J. Meire, L. |
spellingShingle |
van Genuchten, C.M. Rosing, M.T. Hopwood, M.J. Liu, T. Krause, J. Meire, L. Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
author_facet |
van Genuchten, C.M. Rosing, M.T. Hopwood, M.J. Liu, T. Krause, J. Meire, L. |
author_sort |
van Genuchten, C.M. |
title |
Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
title_short |
Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
title_full |
Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
title_fullStr |
Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
title_full_unstemmed |
Decoupling of particles and dissolved iron downstream of Greenlandic glacier outflows |
title_sort |
decoupling of particles and dissolved iron downstream of greenlandic glacier outflows |
publishDate |
2021 |
url |
https://www.vliz.be/imisdocs/publications/80/369180.pdf |
long_lat |
ENVELOPE(-51.000,-51.000,64.117,64.117) |
geographic |
Ameralik Greenland |
geographic_facet |
Ameralik Greenland |
genre |
Ameralik Ameralik fjord Disko Bay glacier Greenland greenlandic |
genre_facet |
Ameralik Ameralik fjord Disko Bay glacier Greenland greenlandic |
op_source |
%3Ci%3EEarth+Planet.+Sci.+Lett.+576%3C%2Fi%3E%3A+117234.+%3Ca+href%3D%22https%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2021.117234%22+target%3D%22_blank%22%3Ehttps%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2021.117234%3C%2Fa%3E |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/000709450900020 info:eu-repo/semantics/altIdentifier/doi/doi.org/10.1016/j.epsl.2021.117234 https://www.vliz.be/imisdocs/publications/80/369180.pdf |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2021.117234 |
container_title |
Earth and Planetary Science Letters |
container_volume |
576 |
container_start_page |
117234 |
_version_ |
1766361013103362048 |