Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard
Our long-term study gives a rare insight into meltwater hydrochemistry following the transition of Austre Brøggerbreen from polythermal to cold-based glaciation and its continued retreat. We find that the processes responsible for ion acquisition did not change throughout the period of records but b...
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Norwegian Polar Institute
2014
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ftdoajarticles:oai:doaj.org/article:e1fb3920eafb460280f1a0b9017e754b 2023-05-15T15:13:36+02:00 Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard Aga Nowak Andy Hodson 2014-10-01T00:00:00Z https://doi.org/10.3402/polar.v33.22779 https://doaj.org/article/e1fb3920eafb460280f1a0b9017e754b EN eng Norwegian Polar Institute http://www.polarresearch.net/index.php/polar/article/download/22779/pdf_1 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v33.22779 https://doaj.org/article/e1fb3920eafb460280f1a0b9017e754b Polar Research, Vol 33, Iss 0, Pp 1-19 (2014) High Arctic Bayelva meltwater geochemistry chemical weathering in glacierized catchment glacier retreat climate change Environmental sciences GE1-350 Oceanography GC1-1581 article 2014 ftdoajarticles https://doi.org/10.3402/polar.v33.22779 2022-12-31T06:59:19Z Our long-term study gives a rare insight into meltwater hydrochemistry following the transition of Austre Brøggerbreen from polythermal to cold-based glaciation and its continued retreat. We find that the processes responsible for ion acquisition did not change throughout the period of records but became more productive. Two regimes before and after July/August 2000 were identified from changes in solute concentrations and pH. They resulted from increased chemical weathering occurring in ice-marginal and proglacial environments that have become progressively exposed by glacier retreat. Carbonate carbonation nearly doubled between 2000 and 2010, whilst increases in the weathering of silicate minerals were also marked. In addition, the end of ablation season chemistry was characterized by reactions in long residence time flow paths like those in subglacial environments, in spite of their absence in the watershed. Furthermore, the retreat of the glacier caused the sudden re-routing of meltwaters through its immediate forefield during 2009, which more than doubled crustal ion yields in this particular year and influenced chemical weathering in 2010 regardless of a low water flux. Such a “flush” of crustally derived ions can be meaningful for downstream terrestrial and marine ecosystems. We therefore find that, during glacier retreat, the recently exposed forefield is the most chemically active part of the watershed, making high rates of weathering possible, even when ice losses have caused a switch to cold-based conditions with no delayed subglacial drainage flowpaths. In addition, the drainage system reorganization events result in significant pCO2 depletion in an otherwise high pCO2 system. Article in Journal/Newspaper Arctic Climate change glacier Polar Research Svalbard Directory of Open Access Journals: DOAJ Articles Arctic Bayelva ENVELOPE(11.898,11.898,78.933,78.933) Svalbard Polar Research 33 1 22779 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
High Arctic Bayelva meltwater geochemistry chemical weathering in glacierized catchment glacier retreat climate change Environmental sciences GE1-350 Oceanography GC1-1581 |
spellingShingle |
High Arctic Bayelva meltwater geochemistry chemical weathering in glacierized catchment glacier retreat climate change Environmental sciences GE1-350 Oceanography GC1-1581 Aga Nowak Andy Hodson Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
topic_facet |
High Arctic Bayelva meltwater geochemistry chemical weathering in glacierized catchment glacier retreat climate change Environmental sciences GE1-350 Oceanography GC1-1581 |
description |
Our long-term study gives a rare insight into meltwater hydrochemistry following the transition of Austre Brøggerbreen from polythermal to cold-based glaciation and its continued retreat. We find that the processes responsible for ion acquisition did not change throughout the period of records but became more productive. Two regimes before and after July/August 2000 were identified from changes in solute concentrations and pH. They resulted from increased chemical weathering occurring in ice-marginal and proglacial environments that have become progressively exposed by glacier retreat. Carbonate carbonation nearly doubled between 2000 and 2010, whilst increases in the weathering of silicate minerals were also marked. In addition, the end of ablation season chemistry was characterized by reactions in long residence time flow paths like those in subglacial environments, in spite of their absence in the watershed. Furthermore, the retreat of the glacier caused the sudden re-routing of meltwaters through its immediate forefield during 2009, which more than doubled crustal ion yields in this particular year and influenced chemical weathering in 2010 regardless of a low water flux. Such a “flush” of crustally derived ions can be meaningful for downstream terrestrial and marine ecosystems. We therefore find that, during glacier retreat, the recently exposed forefield is the most chemically active part of the watershed, making high rates of weathering possible, even when ice losses have caused a switch to cold-based conditions with no delayed subglacial drainage flowpaths. In addition, the drainage system reorganization events result in significant pCO2 depletion in an otherwise high pCO2 system. |
format |
Article in Journal/Newspaper |
author |
Aga Nowak Andy Hodson |
author_facet |
Aga Nowak Andy Hodson |
author_sort |
Aga Nowak |
title |
Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
title_short |
Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
title_full |
Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
title_fullStr |
Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
title_full_unstemmed |
Changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at Austre Brøggerbreen, Svalbard |
title_sort |
changes in meltwater chemistry over a 20-year period following a thermal regime switch from polythermal to cold-based glaciation at austre brøggerbreen, svalbard |
publisher |
Norwegian Polar Institute |
publishDate |
2014 |
url |
https://doi.org/10.3402/polar.v33.22779 https://doaj.org/article/e1fb3920eafb460280f1a0b9017e754b |
long_lat |
ENVELOPE(11.898,11.898,78.933,78.933) |
geographic |
Arctic Bayelva Svalbard |
geographic_facet |
Arctic Bayelva Svalbard |
genre |
Arctic Climate change glacier Polar Research Svalbard |
genre_facet |
Arctic Climate change glacier Polar Research Svalbard |
op_source |
Polar Research, Vol 33, Iss 0, Pp 1-19 (2014) |
op_relation |
http://www.polarresearch.net/index.php/polar/article/download/22779/pdf_1 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v33.22779 https://doaj.org/article/e1fb3920eafb460280f1a0b9017e754b |
op_doi |
https://doi.org/10.3402/polar.v33.22779 |
container_title |
Polar Research |
container_volume |
33 |
container_issue |
1 |
container_start_page |
22779 |
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1766344129316388864 |