The macronutrient and micronutrient (iron and manganese) signature of icebergs
Ice calved from the Antarctic and Greenland Ice Sheets or tidewater glaciers ultimately melts in the ocean contributing to sea-level rise. Icebergs have also been described as biological hotspots due to their potential roles as platforms for marine mammals and birds, and as micronutrient fertilizing...
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Copernicus Publications (EGU)
2024
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Online Access: | https://oceanrep.geomar.de/id/eprint/59799/ https://oceanrep.geomar.de/id/eprint/59799/1/egusphere-2023-2991.pdf https://oceanrep.geomar.de/id/eprint/59799/2/egusphere-2023-2991-supplement.zip https://doi.org/10.5194/egusphere-2023-2991 |
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ftoceanrep:oai:oceanrep.geomar.de:59799 2024-02-11T09:56:39+01:00 The macronutrient and micronutrient (iron and manganese) signature of icebergs Krause, Jana Carroll, Dustin Höfer, Juan Donaire, Jeremy Achterberg, Eric Pieter Alarcón, Emilio Liu, Te Meire, Lorenz Zhu, Kechen Hopwood, Mark James 2024-01-09 text archive https://oceanrep.geomar.de/id/eprint/59799/ https://oceanrep.geomar.de/id/eprint/59799/1/egusphere-2023-2991.pdf https://oceanrep.geomar.de/id/eprint/59799/2/egusphere-2023-2991-supplement.zip https://doi.org/10.5194/egusphere-2023-2991 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/59799/1/egusphere-2023-2991.pdf https://oceanrep.geomar.de/id/eprint/59799/2/egusphere-2023-2991-supplement.zip Krause, J., Carroll, D., Höfer, J., Donaire, J., Achterberg, E. P. , Alarcón, E., Liu, T., Meire, L., Zhu, K. and Hopwood, M. J. (Submitted) The macronutrient and micronutrient (iron and manganese) signature of icebergs. Open Access EGUsphere . DOI 10.5194/egusphere-2023-2991 <https://doi.org/10.5194/egusphere-2023-2991>. doi:10.5194/egusphere-2023-2991 cc_by_4.0 info:eu-repo/semantics/openAccess Article NonPeerReviewed 2024 ftoceanrep https://doi.org/10.5194/egusphere-2023-2991 2024-01-15T00:28:08Z Ice calved from the Antarctic and Greenland Ice Sheets or tidewater glaciers ultimately melts in the ocean contributing to sea-level rise. Icebergs have also been described as biological hotspots due to their potential roles as platforms for marine mammals and birds, and as micronutrient fertilizing agents. Icebergs may be especially important in the Southern Ocean where availability of the micronutrients iron and manganese extensively limits marine primary production. Whilst icebergs have long been described as a source of iron to the ocean, their nutrient signature is poorly constrained and it is unclear if there are regional differences. Here we show that 589 ice fragments collected from floating ice in contrasting regions spanning the Antarctic Peninsula, Greenland, and smaller tidewater systems in Svalbard, Patagonia and Iceland have similar characteristic (micro)nutrient signatures with limited or no significant differences between regions. Icebergs are a minor or negligible source of macronutrients to the ocean with low concentrations of NOx (NO3 + NO2, median 0.51 µM), PO4 (median 0.04 µM), and dissolved Si (dSi, median 0.02 µM). In contrast, icebergs deliver elevated concentrations of dissolved Fe (dFe; mean 82 nM, median 12 nM) and Mn (dMn; mean 26 nM, median 2.6 nM). A tight correlation between total dissolvable Fe and Mn (R2 = 0.95) and a Mn:Fe ratio of 0.024 suggested a lithogenic origin for the majority of sediment present in ice. Total dissolvable Fe and Mn retained a strong relationship with sediment load (both R2 = 0.43, p<0.001), whereas weaker relationships were observed for dFe, dMn and dSi. Sediment load for Antarctic ice (median 9 mg L-1, n=144) was low compared to prior reported values for the Arctic. A particularly curious incidental finding was that melting samples of ice were observed to rapidly lose their sediment load, even when sediment layers were embedded within the ice and stored in the dark. Our results demonstrated that the nutrient signature of icebergs is consistent with an ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Arctic Greenland Iceberg* Iceberg* Iceland Southern Ocean Svalbard OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Antarctic Peninsula Arctic Greenland Patagonia Southern Ocean Svalbard The Antarctic |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Ice calved from the Antarctic and Greenland Ice Sheets or tidewater glaciers ultimately melts in the ocean contributing to sea-level rise. Icebergs have also been described as biological hotspots due to their potential roles as platforms for marine mammals and birds, and as micronutrient fertilizing agents. Icebergs may be especially important in the Southern Ocean where availability of the micronutrients iron and manganese extensively limits marine primary production. Whilst icebergs have long been described as a source of iron to the ocean, their nutrient signature is poorly constrained and it is unclear if there are regional differences. Here we show that 589 ice fragments collected from floating ice in contrasting regions spanning the Antarctic Peninsula, Greenland, and smaller tidewater systems in Svalbard, Patagonia and Iceland have similar characteristic (micro)nutrient signatures with limited or no significant differences between regions. Icebergs are a minor or negligible source of macronutrients to the ocean with low concentrations of NOx (NO3 + NO2, median 0.51 µM), PO4 (median 0.04 µM), and dissolved Si (dSi, median 0.02 µM). In contrast, icebergs deliver elevated concentrations of dissolved Fe (dFe; mean 82 nM, median 12 nM) and Mn (dMn; mean 26 nM, median 2.6 nM). A tight correlation between total dissolvable Fe and Mn (R2 = 0.95) and a Mn:Fe ratio of 0.024 suggested a lithogenic origin for the majority of sediment present in ice. Total dissolvable Fe and Mn retained a strong relationship with sediment load (both R2 = 0.43, p<0.001), whereas weaker relationships were observed for dFe, dMn and dSi. Sediment load for Antarctic ice (median 9 mg L-1, n=144) was low compared to prior reported values for the Arctic. A particularly curious incidental finding was that melting samples of ice were observed to rapidly lose their sediment load, even when sediment layers were embedded within the ice and stored in the dark. Our results demonstrated that the nutrient signature of icebergs is consistent with an ... |
format |
Article in Journal/Newspaper |
author |
Krause, Jana Carroll, Dustin Höfer, Juan Donaire, Jeremy Achterberg, Eric Pieter Alarcón, Emilio Liu, Te Meire, Lorenz Zhu, Kechen Hopwood, Mark James |
spellingShingle |
Krause, Jana Carroll, Dustin Höfer, Juan Donaire, Jeremy Achterberg, Eric Pieter Alarcón, Emilio Liu, Te Meire, Lorenz Zhu, Kechen Hopwood, Mark James The macronutrient and micronutrient (iron and manganese) signature of icebergs |
author_facet |
Krause, Jana Carroll, Dustin Höfer, Juan Donaire, Jeremy Achterberg, Eric Pieter Alarcón, Emilio Liu, Te Meire, Lorenz Zhu, Kechen Hopwood, Mark James |
author_sort |
Krause, Jana |
title |
The macronutrient and micronutrient (iron and manganese) signature of icebergs |
title_short |
The macronutrient and micronutrient (iron and manganese) signature of icebergs |
title_full |
The macronutrient and micronutrient (iron and manganese) signature of icebergs |
title_fullStr |
The macronutrient and micronutrient (iron and manganese) signature of icebergs |
title_full_unstemmed |
The macronutrient and micronutrient (iron and manganese) signature of icebergs |
title_sort |
macronutrient and micronutrient (iron and manganese) signature of icebergs |
publisher |
Copernicus Publications (EGU) |
publishDate |
2024 |
url |
https://oceanrep.geomar.de/id/eprint/59799/ https://oceanrep.geomar.de/id/eprint/59799/1/egusphere-2023-2991.pdf https://oceanrep.geomar.de/id/eprint/59799/2/egusphere-2023-2991-supplement.zip https://doi.org/10.5194/egusphere-2023-2991 |
geographic |
Antarctic Antarctic Peninsula Arctic Greenland Patagonia Southern Ocean Svalbard The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Arctic Greenland Patagonia Southern Ocean Svalbard The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Arctic Greenland Iceberg* Iceberg* Iceland Southern Ocean Svalbard |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Arctic Greenland Iceberg* Iceberg* Iceland Southern Ocean Svalbard |
op_relation |
https://oceanrep.geomar.de/id/eprint/59799/1/egusphere-2023-2991.pdf https://oceanrep.geomar.de/id/eprint/59799/2/egusphere-2023-2991-supplement.zip Krause, J., Carroll, D., Höfer, J., Donaire, J., Achterberg, E. P. , Alarcón, E., Liu, T., Meire, L., Zhu, K. and Hopwood, M. J. (Submitted) The macronutrient and micronutrient (iron and manganese) signature of icebergs. Open Access EGUsphere . DOI 10.5194/egusphere-2023-2991 <https://doi.org/10.5194/egusphere-2023-2991>. doi:10.5194/egusphere-2023-2991 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/egusphere-2023-2991 |
_version_ |
1790604869830180864 |