Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord
The transport of reactive iron (i.e. colloidal and dissolved) by a glacier-fed stream system draining a high relief periglacial landscape in the high Arctic archipelago of Svalbard is described. A negative, non-linear relationship between discharge and iron concentration is found, indicative of incr...
Published in: | Hydrological Processes |
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ftleedsuniv:oai:eprints.whiterose.ac.uk:93419 2023-05-15T14:24:40+02:00 Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord Hodson, A. Nowak, A. Christiansen, H. 2016 text https://eprints.whiterose.ac.uk/93419/ https://eprints.whiterose.ac.uk/93419/1/Hodson,%20Nowak%20%26%20Christiansen%202015%20HP.pdf https://doi.org/10.1002/hyp.10701 en eng Wiley https://eprints.whiterose.ac.uk/93419/1/Hodson,%20Nowak%20%26%20Christiansen%202015%20HP.pdf Hodson, A., Nowak, A. and Christiansen, H. (2016) Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord. Hydrological Processes. ISSN 0885-6087 Article PeerReviewed 2016 ftleedsuniv https://doi.org/10.1002/hyp.10701 2023-01-30T21:37:48Z The transport of reactive iron (i.e. colloidal and dissolved) by a glacier-fed stream system draining a high relief periglacial landscape in the high Arctic archipelago of Svalbard is described. A negative, non-linear relationship between discharge and iron concentration is found, indicative of increased iron acquisition along baseflow pathways. Because the glaciers are cold-based and there are no intra- or sub-permafrost groundwater springs, baseflow is principally supplied by the active layer and the colluvial and alluvial sediments in the lower valley. Collectively, these environments increase the flux of iron in the stream by 40% over a floodplain length of just 8km, resulting in 6kg Fe km-2a-1 of reactive iron export for a 20% glacierized watershed. We show that pyrite oxidation in shallow-groundwater flowpaths of the floodplain is the most important source of reactive iron, although it is far less influential in the upper parts of the catchment where other sources are significant (including ironstone and secondary oxide coatings). Microbial catalysis of the pyrite oxidation occurs in the floodplain, enabling rapid, hyporheic water exchange to enhance the iron fluxes at high discharge and cause the non-linear relationship between discharge and reactive iron concentrations. Furthermore, because the pyrite oxidation is tightly coupled to carbonate and silicate mineral weathering, other nutrients such as base cations and silica are also released to the stream system. Our work therefore shows that high Arctic floodplains should be regarded as critically important regulators of terrestrial nutrient fluxes to coastal ecosystems from glacial and periglacial sources. Article in Journal/Newspaper Arctic Arctic Archipelago Arctic glacier permafrost Svalbard White Rose Research Online (Universities of Leeds, Sheffield & York) Arctic Svalbard Hydrological Processes 30 8 1219 1229 |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
The transport of reactive iron (i.e. colloidal and dissolved) by a glacier-fed stream system draining a high relief periglacial landscape in the high Arctic archipelago of Svalbard is described. A negative, non-linear relationship between discharge and iron concentration is found, indicative of increased iron acquisition along baseflow pathways. Because the glaciers are cold-based and there are no intra- or sub-permafrost groundwater springs, baseflow is principally supplied by the active layer and the colluvial and alluvial sediments in the lower valley. Collectively, these environments increase the flux of iron in the stream by 40% over a floodplain length of just 8km, resulting in 6kg Fe km-2a-1 of reactive iron export for a 20% glacierized watershed. We show that pyrite oxidation in shallow-groundwater flowpaths of the floodplain is the most important source of reactive iron, although it is far less influential in the upper parts of the catchment where other sources are significant (including ironstone and secondary oxide coatings). Microbial catalysis of the pyrite oxidation occurs in the floodplain, enabling rapid, hyporheic water exchange to enhance the iron fluxes at high discharge and cause the non-linear relationship between discharge and reactive iron concentrations. Furthermore, because the pyrite oxidation is tightly coupled to carbonate and silicate mineral weathering, other nutrients such as base cations and silica are also released to the stream system. Our work therefore shows that high Arctic floodplains should be regarded as critically important regulators of terrestrial nutrient fluxes to coastal ecosystems from glacial and periglacial sources. |
format |
Article in Journal/Newspaper |
author |
Hodson, A. Nowak, A. Christiansen, H. |
spellingShingle |
Hodson, A. Nowak, A. Christiansen, H. Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
author_facet |
Hodson, A. Nowak, A. Christiansen, H. |
author_sort |
Hodson, A. |
title |
Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
title_short |
Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
title_full |
Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
title_fullStr |
Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
title_full_unstemmed |
Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
title_sort |
glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord |
publisher |
Wiley |
publishDate |
2016 |
url |
https://eprints.whiterose.ac.uk/93419/ https://eprints.whiterose.ac.uk/93419/1/Hodson,%20Nowak%20%26%20Christiansen%202015%20HP.pdf https://doi.org/10.1002/hyp.10701 |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
Arctic Arctic Archipelago Arctic glacier permafrost Svalbard |
genre_facet |
Arctic Arctic Archipelago Arctic glacier permafrost Svalbard |
op_relation |
https://eprints.whiterose.ac.uk/93419/1/Hodson,%20Nowak%20%26%20Christiansen%202015%20HP.pdf Hodson, A., Nowak, A. and Christiansen, H. (2016) Glacial and periglacial floodplain sediments regulate hydrologic transfer of reactive iron to a high arctic fjord. Hydrological Processes. ISSN 0885-6087 |
op_doi |
https://doi.org/10.1002/hyp.10701 |
container_title |
Hydrological Processes |
container_volume |
30 |
container_issue |
8 |
container_start_page |
1219 |
op_container_end_page |
1229 |
_version_ |
1766297112444665856 |