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 µm) concentrations of trace elements in subglacial waters from...
Published in: | Proceedings of the National Academy of Sciences |
---|---|
Main Authors: | , , , , , , , , , , , , , , , |
Format: | Text |
Language: | English |
Published: |
National Academy of Sciences
2020
|
Subjects: | |
Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749357/ http://www.ncbi.nlm.nih.gov/pubmed/33229559 https://doi.org/10.1073/pnas.2014378117 |
id |
ftpubmed:oai:pubmedcentral.nih.gov:7749357 |
---|---|
record_format |
openpolar |
spelling |
ftpubmed:oai:pubmedcentral.nih.gov:7749357 2023-05-15T13:31:32+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. 2020-12-15 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749357/ http://www.ncbi.nlm.nih.gov/pubmed/33229559 https://doi.org/10.1073/pnas.2014378117 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749357/ http://www.ncbi.nlm.nih.gov/pubmed/33229559 http://dx.doi.org/10.1073/pnas.2014378117 https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . Proc Natl Acad Sci U S A Physical Sciences Text 2020 ftpubmed https://doi.org/10.1073/pnas.2014378117 2021-05-30T00:21:15Z 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 µm) 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 PubMed Central (PMC) Antarctic Greenland Southern Ocean The Antarctic Proceedings of the National Academy of Sciences 117 50 31648 31659 |
institution |
Open Polar |
collection |
PubMed Central (PMC) |
op_collection_id |
ftpubmed |
language |
English |
topic |
Physical Sciences |
spellingShingle |
Physical Sciences 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 |
topic_facet |
Physical Sciences |
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 µm) 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. |
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 |
publisher |
National Academy of Sciences |
publishDate |
2020 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749357/ http://www.ncbi.nlm.nih.gov/pubmed/33229559 https://doi.org/10.1073/pnas.2014378117 |
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 |
Proc Natl Acad Sci U S A |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749357/ http://www.ncbi.nlm.nih.gov/pubmed/33229559 http://dx.doi.org/10.1073/pnas.2014378117 |
op_rights |
https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . |
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 |
_version_ |
1766018693353963520 |