Enhanced trace element mobilization by Earth's ice sheets
Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 mu m) concentrations of trace elements in subglacial waters fr...
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ftinfoscience:oai:infoscience.epfl.ch:284588 2023-05-15T13:44:32+02:00 Enhanced trace element mobilization by Earth's ice sheets Hawkings, Jon R. Skidmore, Mark L. Wadham, Jemma L. Priscu, John C. Morton, Peter L. Hatton, Jade E. Gardner, Christopher B. Kohler, Tyler J. Stibal, Marek Bagshaw, Elizabeth A. Steigmeyer, August Barker, Joel Dore, John E. Lyons, W. Berry Tranter, Martyn Spencer, Robert G. M. 2021-03-26T12:03:36Z https://doi.org/10.1073/pnas.2014378117 http://infoscience.epfl.ch/record/284588 unknown doi:10.1073/pnas.2014378117 isi:000600608300019 http://infoscience.epfl.ch/record/284588 http://infoscience.epfl.ch/record/284588 Text 2021 ftinfoscience https://doi.org/10.1073/pnas.2014378117 2023-02-13T23:04:13Z Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 mu m) concentrations of trace elements in subglacial waters from the Greenland Ice Sheet (GrIS) and the Antarctic Ice Sheet (AIS). Concentrations of immobile trace elements (e.g., Al, Fe, Ti) far exceed global riverine and open ocean mean values and highlight the importance of subglacial aluminosilicate mineral weathering and lack of retention of these species in sediments. Concentrations are higher from the AIS than the GrIS, highlighting the geochemical consequences of prolonged water residence times and hydrological isolation that characterize the former. The enrichment of trace elements (e.g., Co, Fe, Mn, and Zn) in subglacial meltwaters compared with seawater and typical riverine systems, together with the likely sensitivity to future ice sheet melting, suggests that their export in glacial runoff is likely to be important for biological productivity. For example, our dissolved Fe concentration (20,900 nM) and associated flux values (1.4 Gmol y(-1)) from AIS to the Fe-deplete Southern Ocean exceed most previous estimates by an order of magnitude. The ultimate fate of these micronutrients will depend on the reactivity of the dominant colloidal size fraction (likely controlled by nanoparticulate Al and Fe oxyhydroxide minerals) and estuarine processing. We contend that ice sheets create highly geochemically reactive particulates in subglacial environments, which play a key role in trace elemental cycles, with potentially important consequences for global carbon cycling. Text Antarc* Antarctic Greenland Ice Sheet Southern Ocean EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) Antarctic Greenland Southern Ocean The Antarctic Proceedings of the National Academy of Sciences 117 50 31648 31659 |
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Open Polar |
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EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) |
op_collection_id |
ftinfoscience |
language |
unknown |
description |
Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 mu m) concentrations of trace elements in subglacial waters from the Greenland Ice Sheet (GrIS) and the Antarctic Ice Sheet (AIS). Concentrations of immobile trace elements (e.g., Al, Fe, Ti) far exceed global riverine and open ocean mean values and highlight the importance of subglacial aluminosilicate mineral weathering and lack of retention of these species in sediments. Concentrations are higher from the AIS than the GrIS, highlighting the geochemical consequences of prolonged water residence times and hydrological isolation that characterize the former. The enrichment of trace elements (e.g., Co, Fe, Mn, and Zn) in subglacial meltwaters compared with seawater and typical riverine systems, together with the likely sensitivity to future ice sheet melting, suggests that their export in glacial runoff is likely to be important for biological productivity. For example, our dissolved Fe concentration (20,900 nM) and associated flux values (1.4 Gmol y(-1)) from AIS to the Fe-deplete Southern Ocean exceed most previous estimates by an order of magnitude. The ultimate fate of these micronutrients will depend on the reactivity of the dominant colloidal size fraction (likely controlled by nanoparticulate Al and Fe oxyhydroxide minerals) and estuarine processing. We contend that ice sheets create highly geochemically reactive particulates in subglacial environments, which play a key role in trace elemental cycles, with potentially important consequences for global carbon cycling. |
format |
Text |
author |
Hawkings, Jon R. Skidmore, Mark L. Wadham, Jemma L. Priscu, John C. Morton, Peter L. Hatton, Jade E. Gardner, Christopher B. Kohler, Tyler J. Stibal, Marek Bagshaw, Elizabeth A. Steigmeyer, August Barker, Joel Dore, John E. Lyons, W. Berry Tranter, Martyn Spencer, Robert G. M. |
spellingShingle |
Hawkings, Jon R. Skidmore, Mark L. Wadham, Jemma L. Priscu, John C. Morton, Peter L. Hatton, Jade E. Gardner, Christopher B. Kohler, Tyler J. Stibal, Marek Bagshaw, Elizabeth A. Steigmeyer, August Barker, Joel Dore, John E. Lyons, W. Berry Tranter, Martyn Spencer, Robert G. M. Enhanced trace element mobilization by Earth's ice sheets |
author_facet |
Hawkings, Jon R. Skidmore, Mark L. Wadham, Jemma L. Priscu, John C. Morton, Peter L. Hatton, Jade E. Gardner, Christopher B. Kohler, Tyler J. Stibal, Marek Bagshaw, Elizabeth A. Steigmeyer, August Barker, Joel Dore, John E. Lyons, W. Berry Tranter, Martyn Spencer, Robert G. M. |
author_sort |
Hawkings, Jon R. |
title |
Enhanced trace element mobilization by Earth's ice sheets |
title_short |
Enhanced trace element mobilization by Earth's ice sheets |
title_full |
Enhanced trace element mobilization by Earth's ice sheets |
title_fullStr |
Enhanced trace element mobilization by Earth's ice sheets |
title_full_unstemmed |
Enhanced trace element mobilization by Earth's ice sheets |
title_sort |
enhanced trace element mobilization by earth's ice sheets |
publishDate |
2021 |
url |
https://doi.org/10.1073/pnas.2014378117 http://infoscience.epfl.ch/record/284588 |
geographic |
Antarctic Greenland Southern Ocean The Antarctic |
geographic_facet |
Antarctic Greenland Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Greenland Ice Sheet Southern Ocean |
genre_facet |
Antarc* Antarctic Greenland Ice Sheet Southern Ocean |
op_source |
http://infoscience.epfl.ch/record/284588 |
op_relation |
doi:10.1073/pnas.2014378117 isi:000600608300019 http://infoscience.epfl.ch/record/284588 |
op_doi |
https://doi.org/10.1073/pnas.2014378117 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
117 |
container_issue |
50 |
container_start_page |
31648 |
op_container_end_page |
31659 |
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1766202853895962624 |