Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ

Concentrations of the toxic element lead (Pb) are elevated in seawater due to historical emissions. While anthropogenic atmospheric emissions are the dominant source of dissolved Pb (dPb) to the Atlantic Ocean, evidence is emerging of a natural source associated with subglacial discharge into the oc...

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Published in:Geophysical Research Letters
Main Authors: Krisch, Stephan, Huhn, Oliver, Al-Hashem, Ali, Hopwood, Mark J., Lodeiro, Pablo, Achterberg, Eric P.
Format: Article in Journal/Newspaper
Language:English
Published: AGU (American Geophysical Union) 2022
Subjects:
Online Access:https://oceanrep.geomar.de/id/eprint/57245/
https://oceanrep.geomar.de/id/eprint/57245/1/Geophysical%20Research%20Letters%20-%202022%20-%20Krisch%20-%20Quantifying%20Ice%E2%80%90Sheet%20Derived%20Lead%20Pb%20Fluxes%20to%20the%20Ocean%20A%20Case%20Study%20at.pdf
https://oceanrep.geomar.de/id/eprint/57245/7/2022gl100296-sup-0001-supporting%20information%20si-s01.pdf
https://doi.org/10.1029/2022GL100296
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spelling ftoceanrep:oai:oceanrep.geomar.de:57245 2024-02-11T10:01:23+01:00 Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ Krisch, Stephan Huhn, Oliver Al-Hashem, Ali Hopwood, Mark J. Lodeiro, Pablo Achterberg, Eric P. 2022-11-16 text https://oceanrep.geomar.de/id/eprint/57245/ https://oceanrep.geomar.de/id/eprint/57245/1/Geophysical%20Research%20Letters%20-%202022%20-%20Krisch%20-%20Quantifying%20Ice%E2%80%90Sheet%20Derived%20Lead%20Pb%20Fluxes%20to%20the%20Ocean%20A%20Case%20Study%20at.pdf https://oceanrep.geomar.de/id/eprint/57245/7/2022gl100296-sup-0001-supporting%20information%20si-s01.pdf https://doi.org/10.1029/2022GL100296 en eng AGU (American Geophysical Union) Wiley https://oceanrep.geomar.de/id/eprint/57245/1/Geophysical%20Research%20Letters%20-%202022%20-%20Krisch%20-%20Quantifying%20Ice%E2%80%90Sheet%20Derived%20Lead%20Pb%20Fluxes%20to%20the%20Ocean%20A%20Case%20Study%20at.pdf https://oceanrep.geomar.de/id/eprint/57245/7/2022gl100296-sup-0001-supporting%20information%20si-s01.pdf Krisch, S. , Huhn, O., Al-Hashem, A., Hopwood, M. J. , Lodeiro, P. and Achterberg, E. P. (2022) Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ. Open Access Geophysical Research Letters, 49 (21). e2022GL100296. DOI 10.1029/2022GL100296 <https://doi.org/10.1029/2022GL100296>. doi:10.1029/2022GL100296 cc_by_nc_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed info:eu-repo/semantics/article 2022 ftoceanrep https://doi.org/10.1029/2022GL100296 2024-01-15T00:26:12Z Concentrations of the toxic element lead (Pb) are elevated in seawater due to historical emissions. While anthropogenic atmospheric emissions are the dominant source of dissolved Pb (dPb) to the Atlantic Ocean, evidence is emerging of a natural source associated with subglacial discharge into the ocean but this has yet to be constrained around Greenland. Here, we show subglacial discharge from the cavity underneath Nioghalvfjerdsbræ floating ice tongue, is a previously unrecognized source of dPb to the NE Greenland Shelf. Contrasting cavity-inflowing and cavity-outflowing waters, we constrain the associated net-dPb flux as 2.2 ± 1.4 Mg·yr−1, of which ∼90% originates from dissolution of glacial bedrock and cavity sediments. We propose that the retreat of the floating ice tongue, the ongoing retreat of many glaciers on Greenland, associated shifts in sediment dynamics, and enhanced meltwater discharges into shelf waters may result in pronounced changes, possibly increases, in net-dPb fluxes to coastal waters. Key Points - Helium and neon show strong evidence for a subglacial source of Pb discharging onto the NE Greenland Shelf - Contrasting inflowing and outflowing waters beneath the floating ice tongue of Nioghalvfjerdsbræ shows a 2-3-fold dPb enrichment - The dissolved Pb flux from Nioghalvfjerdsbræ (2.2 ± 1.4 Mg·yr−1) is comparable to small Arctic rivers, with ∼90% of a sedimentary origin Article in Journal/Newspaper Arctic Greenland Ice Sheet OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Greenland Geophysical Research Letters 49 21
institution Open Polar
collection OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
op_collection_id ftoceanrep
language English
description Concentrations of the toxic element lead (Pb) are elevated in seawater due to historical emissions. While anthropogenic atmospheric emissions are the dominant source of dissolved Pb (dPb) to the Atlantic Ocean, evidence is emerging of a natural source associated with subglacial discharge into the ocean but this has yet to be constrained around Greenland. Here, we show subglacial discharge from the cavity underneath Nioghalvfjerdsbræ floating ice tongue, is a previously unrecognized source of dPb to the NE Greenland Shelf. Contrasting cavity-inflowing and cavity-outflowing waters, we constrain the associated net-dPb flux as 2.2 ± 1.4 Mg·yr−1, of which ∼90% originates from dissolution of glacial bedrock and cavity sediments. We propose that the retreat of the floating ice tongue, the ongoing retreat of many glaciers on Greenland, associated shifts in sediment dynamics, and enhanced meltwater discharges into shelf waters may result in pronounced changes, possibly increases, in net-dPb fluxes to coastal waters. Key Points - Helium and neon show strong evidence for a subglacial source of Pb discharging onto the NE Greenland Shelf - Contrasting inflowing and outflowing waters beneath the floating ice tongue of Nioghalvfjerdsbræ shows a 2-3-fold dPb enrichment - The dissolved Pb flux from Nioghalvfjerdsbræ (2.2 ± 1.4 Mg·yr−1) is comparable to small Arctic rivers, with ∼90% of a sedimentary origin
format Article in Journal/Newspaper
author Krisch, Stephan
Huhn, Oliver
Al-Hashem, Ali
Hopwood, Mark J.
Lodeiro, Pablo
Achterberg, Eric P.
spellingShingle Krisch, Stephan
Huhn, Oliver
Al-Hashem, Ali
Hopwood, Mark J.
Lodeiro, Pablo
Achterberg, Eric P.
Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
author_facet Krisch, Stephan
Huhn, Oliver
Al-Hashem, Ali
Hopwood, Mark J.
Lodeiro, Pablo
Achterberg, Eric P.
author_sort Krisch, Stephan
title Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
title_short Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
title_full Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
title_fullStr Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
title_full_unstemmed Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ
title_sort quantifying ice‐sheet derived lead (pb) fluxes to the ocean; a case study at nioghalvfjerdsbræ
publisher AGU (American Geophysical Union)
publishDate 2022
url https://oceanrep.geomar.de/id/eprint/57245/
https://oceanrep.geomar.de/id/eprint/57245/1/Geophysical%20Research%20Letters%20-%202022%20-%20Krisch%20-%20Quantifying%20Ice%E2%80%90Sheet%20Derived%20Lead%20Pb%20Fluxes%20to%20the%20Ocean%20A%20Case%20Study%20at.pdf
https://oceanrep.geomar.de/id/eprint/57245/7/2022gl100296-sup-0001-supporting%20information%20si-s01.pdf
https://doi.org/10.1029/2022GL100296
geographic Arctic
Greenland
geographic_facet Arctic
Greenland
genre Arctic
Greenland
Ice Sheet
genre_facet Arctic
Greenland
Ice Sheet
op_relation https://oceanrep.geomar.de/id/eprint/57245/1/Geophysical%20Research%20Letters%20-%202022%20-%20Krisch%20-%20Quantifying%20Ice%E2%80%90Sheet%20Derived%20Lead%20Pb%20Fluxes%20to%20the%20Ocean%20A%20Case%20Study%20at.pdf
https://oceanrep.geomar.de/id/eprint/57245/7/2022gl100296-sup-0001-supporting%20information%20si-s01.pdf
Krisch, S. , Huhn, O., Al-Hashem, A., Hopwood, M. J. , Lodeiro, P. and Achterberg, E. P. (2022) Quantifying Ice‐Sheet Derived Lead (Pb) Fluxes to the Ocean; A Case Study at Nioghalvfjerdsbræ. Open Access Geophysical Research Letters, 49 (21). e2022GL100296. DOI 10.1029/2022GL100296 <https://doi.org/10.1029/2022GL100296>.
doi:10.1029/2022GL100296
op_rights cc_by_nc_4.0
info:eu-repo/semantics/openAccess
op_doi https://doi.org/10.1029/2022GL100296
container_title Geophysical Research Letters
container_volume 49
container_issue 21
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