Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies
Abstract Enhanced warming of the Northern high latitudes has intensified thermokarst processes throughout the permafrost zone. Retrogressive thaw slumps (RTS), where thaw-driven erosion caused by ground ice melt creates terrain disturbances extending over tens of hectares, represent particularly dyn...
Published in: | Environmental Research Letters |
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Online Access: | http://dx.doi.org/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b/pdf |
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crioppubl:10.1088/1748-9326/abee4b 2024-06-23T07:50:46+00:00 Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies Bröder, Lisa Keskitalo, Kirsi Zolkos, Scott Shakil, Sarah Tank, Suzanne E Kokelj, Steve V Tesi, Tommaso Van Dongen, Bart E Haghipour, Negar Eglinton, Timothy I Vonk, Jorien E H2020 European Research Council 2021 http://dx.doi.org/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b/pdf unknown IOP Publishing http://creativecommons.org/licenses/by/4.0 https://iopscience.iop.org/info/page/text-and-data-mining Environmental Research Letters volume 16, issue 5, page 054059 ISSN 1748-9326 journal-article 2021 crioppubl https://doi.org/10.1088/1748-9326/abee4b 2024-05-27T13:03:07Z Abstract Enhanced warming of the Northern high latitudes has intensified thermokarst processes throughout the permafrost zone. Retrogressive thaw slumps (RTS), where thaw-driven erosion caused by ground ice melt creates terrain disturbances extending over tens of hectares, represent particularly dynamic thermokarst features. Biogeochemical transformation of the mobilized substrate may release CO 2 to the atmosphere and impact downstream ecosystems, yet its fate remains unclear. The Peel Plateau in northwestern Canada hosts some of the largest RTS features in the Arctic. Here, thick deposits of Pleistocene-aged glacial tills are overlain by a thinner layer of relatively organic-rich Holocene-aged permafrost that aggraded upward following deeper thaw and soil development during the early Holocene warm period. In this study, we characterize exposed soil layers and the mobilized material by analysing sediment properties and organic matter composition in active layer, Holocene and Pleistocene permafrost, recently thawed debris deposits and fresh deposits of slump outflow from four separate RTS features. We found that organic matter content, radiocarbon age and biomarker concentrations in debris and outflow deposits from all four sites were most similar to permafrost soils, with a lesser influence of the organic-rich active layer. Lipid biomarkers suggested a significant contribution of petrogenic carbon especially in Pleistocene permafrost. Active layer samples contained abundant intrinsically labile macromolecular components (polysaccharides, lignin markers, phenolic and N-containing compounds). All other samples were dominated by degraded organic constituents. Active layer soils, although heterogeneous, also had the highest median grain sizes, whereas debris and runoff deposits consisted of finer mineral grains and were generally more homogeneous, similar to permafrost. We thus infer that both organic matter degradation and hydrodynamic sorting during transport affect the mobilized material. Determining the ... Article in Journal/Newspaper Arctic Ice permafrost Thermokarst IOP Publishing Arctic Canada Environmental Research Letters 16 5 054059 |
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Open Polar |
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IOP Publishing |
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crioppubl |
language |
unknown |
description |
Abstract Enhanced warming of the Northern high latitudes has intensified thermokarst processes throughout the permafrost zone. Retrogressive thaw slumps (RTS), where thaw-driven erosion caused by ground ice melt creates terrain disturbances extending over tens of hectares, represent particularly dynamic thermokarst features. Biogeochemical transformation of the mobilized substrate may release CO 2 to the atmosphere and impact downstream ecosystems, yet its fate remains unclear. The Peel Plateau in northwestern Canada hosts some of the largest RTS features in the Arctic. Here, thick deposits of Pleistocene-aged glacial tills are overlain by a thinner layer of relatively organic-rich Holocene-aged permafrost that aggraded upward following deeper thaw and soil development during the early Holocene warm period. In this study, we characterize exposed soil layers and the mobilized material by analysing sediment properties and organic matter composition in active layer, Holocene and Pleistocene permafrost, recently thawed debris deposits and fresh deposits of slump outflow from four separate RTS features. We found that organic matter content, radiocarbon age and biomarker concentrations in debris and outflow deposits from all four sites were most similar to permafrost soils, with a lesser influence of the organic-rich active layer. Lipid biomarkers suggested a significant contribution of petrogenic carbon especially in Pleistocene permafrost. Active layer samples contained abundant intrinsically labile macromolecular components (polysaccharides, lignin markers, phenolic and N-containing compounds). All other samples were dominated by degraded organic constituents. Active layer soils, although heterogeneous, also had the highest median grain sizes, whereas debris and runoff deposits consisted of finer mineral grains and were generally more homogeneous, similar to permafrost. We thus infer that both organic matter degradation and hydrodynamic sorting during transport affect the mobilized material. Determining the ... |
author2 |
H2020 European Research Council |
format |
Article in Journal/Newspaper |
author |
Bröder, Lisa Keskitalo, Kirsi Zolkos, Scott Shakil, Sarah Tank, Suzanne E Kokelj, Steve V Tesi, Tommaso Van Dongen, Bart E Haghipour, Negar Eglinton, Timothy I Vonk, Jorien E |
spellingShingle |
Bröder, Lisa Keskitalo, Kirsi Zolkos, Scott Shakil, Sarah Tank, Suzanne E Kokelj, Steve V Tesi, Tommaso Van Dongen, Bart E Haghipour, Negar Eglinton, Timothy I Vonk, Jorien E Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
author_facet |
Bröder, Lisa Keskitalo, Kirsi Zolkos, Scott Shakil, Sarah Tank, Suzanne E Kokelj, Steve V Tesi, Tommaso Van Dongen, Bart E Haghipour, Negar Eglinton, Timothy I Vonk, Jorien E |
author_sort |
Bröder, Lisa |
title |
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
title_short |
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
title_full |
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
title_fullStr |
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
title_full_unstemmed |
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
title_sort |
preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies |
publisher |
IOP Publishing |
publishDate |
2021 |
url |
http://dx.doi.org/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b https://iopscience.iop.org/article/10.1088/1748-9326/abee4b/pdf |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Ice permafrost Thermokarst |
genre_facet |
Arctic Ice permafrost Thermokarst |
op_source |
Environmental Research Letters volume 16, issue 5, page 054059 ISSN 1748-9326 |
op_rights |
http://creativecommons.org/licenses/by/4.0 https://iopscience.iop.org/info/page/text-and-data-mining |
op_doi |
https://doi.org/10.1088/1748-9326/abee4b |
container_title |
Environmental Research Letters |
container_volume |
16 |
container_issue |
5 |
container_start_page |
054059 |
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1802641683446235136 |