Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies
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 ther...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/486770 2023-08-20T04:04:53+02:00 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. 2021-05 application/application/pdf https://hdl.handle.net/20.500.11850/486770 https://doi.org/10.3929/ethz-b-000486770 en eng IOP Publishing info:eu-repo/semantics/altIdentifier/doi/10.1088/1748-9326/abee4b info:eu-repo/semantics/altIdentifier/wos/000648713800001 http://hdl.handle.net/20.500.11850/486770 doi:10.3929/ethz-b-000486770 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International Environmental Research Letters, 16 (5) carbon cycle climate change cryosphere thermokarst info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftethz https://doi.org/20.500.11850/48677010.3929/ethz-b-00048677010.1088/1748-9326/abee4b 2023-07-30T23:53:38Z 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 CO2 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 relative ... Article in Journal/Newspaper Arctic Climate change Ice permafrost Thermokarst ETH Zürich Research Collection Arctic Canada |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
topic |
carbon cycle climate change cryosphere thermokarst |
spellingShingle |
carbon cycle climate change cryosphere thermokarst 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 |
topic_facet |
carbon cycle climate change cryosphere thermokarst |
description |
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 CO2 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 relative ... |
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. |
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 |
https://hdl.handle.net/20.500.11850/486770 https://doi.org/10.3929/ethz-b-000486770 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Climate change Ice permafrost Thermokarst |
genre_facet |
Arctic Climate change Ice permafrost Thermokarst |
op_source |
Environmental Research Letters, 16 (5) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1088/1748-9326/abee4b info:eu-repo/semantics/altIdentifier/wos/000648713800001 http://hdl.handle.net/20.500.11850/486770 doi:10.3929/ethz-b-000486770 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/48677010.3929/ethz-b-00048677010.1088/1748-9326/abee4b |
_version_ |
1774715293716709376 |