Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea
Ongoing permafrost thaw in the Arctic may remobilize large amounts of old organic matter. Upon transport to the Siberian shelf seas, this material may be degraded and released to the atmosphere, exported off-shelf, or buried in the sediments. While our understanding of the fate of permafrost-derived...
Published in: | Global Biogeochemical Cycles |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2019
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Online Access: | https://research.vu.nl/en/publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 https://doi.org/10.1029/2018GB005967 https://hdl.handle.net/1871.1/2f47680d-3d7c-4c34-addf-a1a9ca75f234 http://www.scopus.com/inward/record.url?scp=85060824845&partnerID=8YFLogxK http://www.scopus.com/inward/citedby.url?scp=85060824845&partnerID=8YFLogxK |
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ftvuamstcris:oai:research.vu.nl:publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 2024-09-15T18:04:24+00:00 Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea Bröder, Lisa Andersson, August Tesi, Tommaso Semiletov, Igor Gustafsson, Örjan 2019-01-01 https://research.vu.nl/en/publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 https://doi.org/10.1029/2018GB005967 https://hdl.handle.net/1871.1/2f47680d-3d7c-4c34-addf-a1a9ca75f234 http://www.scopus.com/inward/record.url?scp=85060824845&partnerID=8YFLogxK http://www.scopus.com/inward/citedby.url?scp=85060824845&partnerID=8YFLogxK eng eng https://research.vu.nl/en/publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 info:eu-repo/semantics/openAccess Bröder , L , Andersson , A , Tesi , T , Semiletov , I & Gustafsson , Ö 2019 , ' Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea ' , Global Biogeochemical Cycles , vol. 33 , no. 1 , pp. 85-99 . https://doi.org/10.1029/2018GB005967 Arctic shelves carbon fluxes degradation marine sediments permafrost /dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water article 2019 ftvuamstcris https://doi.org/10.1029/2018GB005967 2024-07-03T23:47:27Z Ongoing permafrost thaw in the Arctic may remobilize large amounts of old organic matter. Upon transport to the Siberian shelf seas, this material may be degraded and released to the atmosphere, exported off-shelf, or buried in the sediments. While our understanding of the fate of permafrost-derived organic matter in shelf waters is improving, poor constraints remain regarding degradation in sediments. Here we use an extensive data set of organic carbon concentrations and isotopes (n = 109) to inventory terrigenous organic carbon (terrOC) in surficial sediments of the Laptev and East Siberian Seas (LS + ESS). Of these ~2.7 Tg terrOC about 55% appear resistant to degradation on a millennial timescale. A first-order degradation rate constant of 1.5 kyr −1 is derived by combining a previously established relationship between water depth and cross-shelf sediment-terrOC transport time with mineral-associated terrOC loadings. This yields a terrOC degradation flux of ~1.7 Gg/year from surficial sediments during cross-shelf transport, which is orders of magnitude lower than earlier estimates for degradation fluxes of dissolved and particulate terrOC in the water column of the LS + ESS. The difference is mainly due to the low degradation rate constant of sedimentary terrOC, likely caused by a combination of factors: (i) the lower availability of oxygen in the sediments compared to fully oxygenated waters, (ii) the stabilizing role of terrOC-mineral associations, and (iii) the higher proportion of material that is intrinsically recalcitrant due to its chemical/molecular structure in sediments. Sequestration of permafrost-released terrOC in shelf sediments may thereby attenuate the otherwise expected permafrost carbon-climate feedback. Article in Journal/Newspaper East Siberian Sea laptev permafrost Vrije Universiteit Amsterdam (VU): Research Portal Global Biogeochemical Cycles 33 1 85 99 |
institution |
Open Polar |
collection |
Vrije Universiteit Amsterdam (VU): Research Portal |
op_collection_id |
ftvuamstcris |
language |
English |
topic |
Arctic shelves carbon fluxes degradation marine sediments permafrost /dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water |
spellingShingle |
Arctic shelves carbon fluxes degradation marine sediments permafrost /dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water Bröder, Lisa Andersson, August Tesi, Tommaso Semiletov, Igor Gustafsson, Örjan Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
topic_facet |
Arctic shelves carbon fluxes degradation marine sediments permafrost /dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water |
description |
Ongoing permafrost thaw in the Arctic may remobilize large amounts of old organic matter. Upon transport to the Siberian shelf seas, this material may be degraded and released to the atmosphere, exported off-shelf, or buried in the sediments. While our understanding of the fate of permafrost-derived organic matter in shelf waters is improving, poor constraints remain regarding degradation in sediments. Here we use an extensive data set of organic carbon concentrations and isotopes (n = 109) to inventory terrigenous organic carbon (terrOC) in surficial sediments of the Laptev and East Siberian Seas (LS + ESS). Of these ~2.7 Tg terrOC about 55% appear resistant to degradation on a millennial timescale. A first-order degradation rate constant of 1.5 kyr −1 is derived by combining a previously established relationship between water depth and cross-shelf sediment-terrOC transport time with mineral-associated terrOC loadings. This yields a terrOC degradation flux of ~1.7 Gg/year from surficial sediments during cross-shelf transport, which is orders of magnitude lower than earlier estimates for degradation fluxes of dissolved and particulate terrOC in the water column of the LS + ESS. The difference is mainly due to the low degradation rate constant of sedimentary terrOC, likely caused by a combination of factors: (i) the lower availability of oxygen in the sediments compared to fully oxygenated waters, (ii) the stabilizing role of terrOC-mineral associations, and (iii) the higher proportion of material that is intrinsically recalcitrant due to its chemical/molecular structure in sediments. Sequestration of permafrost-released terrOC in shelf sediments may thereby attenuate the otherwise expected permafrost carbon-climate feedback. |
format |
Article in Journal/Newspaper |
author |
Bröder, Lisa Andersson, August Tesi, Tommaso Semiletov, Igor Gustafsson, Örjan |
author_facet |
Bröder, Lisa Andersson, August Tesi, Tommaso Semiletov, Igor Gustafsson, Örjan |
author_sort |
Bröder, Lisa |
title |
Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
title_short |
Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
title_full |
Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
title_fullStr |
Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
title_full_unstemmed |
Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea |
title_sort |
quantifying degradative loss of terrigenous organic carbon in surface sediments across the laptev and east siberian sea |
publishDate |
2019 |
url |
https://research.vu.nl/en/publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 https://doi.org/10.1029/2018GB005967 https://hdl.handle.net/1871.1/2f47680d-3d7c-4c34-addf-a1a9ca75f234 http://www.scopus.com/inward/record.url?scp=85060824845&partnerID=8YFLogxK http://www.scopus.com/inward/citedby.url?scp=85060824845&partnerID=8YFLogxK |
genre |
East Siberian Sea laptev permafrost |
genre_facet |
East Siberian Sea laptev permafrost |
op_source |
Bröder , L , Andersson , A , Tesi , T , Semiletov , I & Gustafsson , Ö 2019 , ' Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea ' , Global Biogeochemical Cycles , vol. 33 , no. 1 , pp. 85-99 . https://doi.org/10.1029/2018GB005967 |
op_relation |
https://research.vu.nl/en/publications/2f47680d-3d7c-4c34-addf-a1a9ca75f234 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2018GB005967 |
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Global Biogeochemical Cycles |
container_volume |
33 |
container_issue |
1 |
container_start_page |
85 |
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99 |
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1810441895522861056 |