Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation
Cryospheric changes in northern high latitudes are linked to significant greenhouse gas flux to the atmosphere, for example, methane that originates from organic matter decomposition in thermokarst lakes. The set of pathways that link methane production in sediments, via oxidation in the lake system...
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2016
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Online Access: | https://hdl.handle.net/1983/976c3e92-2180-4387-8cde-999641c55a4a https://research-information.bris.ac.uk/en/publications/976c3e92-2180-4387-8cde-999641c55a4a https://doi.org/10.5194/bg-13-2611-2016 https://research-information.bris.ac.uk/ws/files/89444505/bg_13_2611_2016.pdf http://www.scopus.com/inward/record.url?scp=84966863514&partnerID=8YFLogxK |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/976c3e92-2180-4387-8cde-999641c55a4a 2024-04-21T08:12:43+00:00 Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation Davies, Kimberley L Pancost, Richard D. Edwards, Mary E. Walter Anthony, Katey M. Langdon, Peter G. Torres, Lidia Chaves 2016-05 application/pdf https://hdl.handle.net/1983/976c3e92-2180-4387-8cde-999641c55a4a https://research-information.bris.ac.uk/en/publications/976c3e92-2180-4387-8cde-999641c55a4a https://doi.org/10.5194/bg-13-2611-2016 https://research-information.bris.ac.uk/ws/files/89444505/bg_13_2611_2016.pdf http://www.scopus.com/inward/record.url?scp=84966863514&partnerID=8YFLogxK eng eng https://research-information.bris.ac.uk/en/publications/976c3e92-2180-4387-8cde-999641c55a4a info:eu-repo/semantics/openAccess Davies , K L , Pancost , R D , Edwards , M E , Walter Anthony , K M , Langdon , P G & Torres , L C 2016 , ' Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation ' , Biogeosciences , vol. 13 , no. 8 , pp. 2611-2621 . https://doi.org/10.5194/bg-13-2611-2016 article 2016 ftubristolcris https://doi.org/10.5194/bg-13-2611-2016 2024-03-27T15:15:18Z Cryospheric changes in northern high latitudes are linked to significant greenhouse gas flux to the atmosphere, for example, methane that originates from organic matter decomposition in thermokarst lakes. The set of pathways that link methane production in sediments, via oxidation in the lake system, to the flux of residual methane to the atmosphere is complex and exhibits temporal and spatial variation. The isotopic signal of bacterial biomarkers (hopanoids, e.g. diploptene) in sediments has been used to identify contemporary ocean-floor methane seeps and, in the geological record, periods of enhanced methane production (e.g. the PETM). The biomarker approach could potentially be used to assess temporal changes in lake emissions through the Holocene via the sedimentary biomarker record. However, there are no data on the consistency of the signal of isotopic depletion in relation to source or on the amount of noise (unexplained variation) in biomarker values from modern lake sediments. We assessed methane oxidation as represented by the isotopic signal of biomarkers from methane oxidising bacteria (MOB) in multiple surface sediment samples in three distinct areas known to emit varying levels of methane in two shallow Alaskan thermokarst lakes. Diploptene was present and had δ 13 C values lower than -38g‰ in all sediments analysed, suggesting methane oxidation was widespread. However, there was considerable variation in δ 13 C values within each area. The most 13 C-depleted diploptene was found in an area of high methane ebullition in Ace Lake (diploptene δ 13 C values between -68.2 and -50.1‰). In contrast, significantly higher diploptene δ 13 C values (between -42.9 and -38.8g‰) were found in an area of methane ebullition in Smith Lake. δ 13 C values of diploptene between -56.8 and -46.9g‰ were found in the centre of Smith Lake, where ebullition rates are low but diffusive methane efflux occurs. The small-scale heterogeneity of the samples may reflect patchy distribution of substrate and/or MOB within the ... Article in Journal/Newspaper Thermokarst University of Bristol: Bristol Research Biogeosciences 13 8 2611 2621 |
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Open Polar |
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University of Bristol: Bristol Research |
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ftubristolcris |
language |
English |
description |
Cryospheric changes in northern high latitudes are linked to significant greenhouse gas flux to the atmosphere, for example, methane that originates from organic matter decomposition in thermokarst lakes. The set of pathways that link methane production in sediments, via oxidation in the lake system, to the flux of residual methane to the atmosphere is complex and exhibits temporal and spatial variation. The isotopic signal of bacterial biomarkers (hopanoids, e.g. diploptene) in sediments has been used to identify contemporary ocean-floor methane seeps and, in the geological record, periods of enhanced methane production (e.g. the PETM). The biomarker approach could potentially be used to assess temporal changes in lake emissions through the Holocene via the sedimentary biomarker record. However, there are no data on the consistency of the signal of isotopic depletion in relation to source or on the amount of noise (unexplained variation) in biomarker values from modern lake sediments. We assessed methane oxidation as represented by the isotopic signal of biomarkers from methane oxidising bacteria (MOB) in multiple surface sediment samples in three distinct areas known to emit varying levels of methane in two shallow Alaskan thermokarst lakes. Diploptene was present and had δ 13 C values lower than -38g‰ in all sediments analysed, suggesting methane oxidation was widespread. However, there was considerable variation in δ 13 C values within each area. The most 13 C-depleted diploptene was found in an area of high methane ebullition in Ace Lake (diploptene δ 13 C values between -68.2 and -50.1‰). In contrast, significantly higher diploptene δ 13 C values (between -42.9 and -38.8g‰) were found in an area of methane ebullition in Smith Lake. δ 13 C values of diploptene between -56.8 and -46.9g‰ were found in the centre of Smith Lake, where ebullition rates are low but diffusive methane efflux occurs. The small-scale heterogeneity of the samples may reflect patchy distribution of substrate and/or MOB within the ... |
format |
Article in Journal/Newspaper |
author |
Davies, Kimberley L Pancost, Richard D. Edwards, Mary E. Walter Anthony, Katey M. Langdon, Peter G. Torres, Lidia Chaves |
spellingShingle |
Davies, Kimberley L Pancost, Richard D. Edwards, Mary E. Walter Anthony, Katey M. Langdon, Peter G. Torres, Lidia Chaves Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
author_facet |
Davies, Kimberley L Pancost, Richard D. Edwards, Mary E. Walter Anthony, Katey M. Langdon, Peter G. Torres, Lidia Chaves |
author_sort |
Davies, Kimberley L |
title |
Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
title_short |
Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
title_full |
Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
title_fullStr |
Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
title_full_unstemmed |
Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation |
title_sort |
diploptene δ 13 c values from contemporary thermokarst lake sediments show complex spatial variation |
publishDate |
2016 |
url |
https://hdl.handle.net/1983/976c3e92-2180-4387-8cde-999641c55a4a https://research-information.bris.ac.uk/en/publications/976c3e92-2180-4387-8cde-999641c55a4a https://doi.org/10.5194/bg-13-2611-2016 https://research-information.bris.ac.uk/ws/files/89444505/bg_13_2611_2016.pdf http://www.scopus.com/inward/record.url?scp=84966863514&partnerID=8YFLogxK |
genre |
Thermokarst |
genre_facet |
Thermokarst |
op_source |
Davies , K L , Pancost , R D , Edwards , M E , Walter Anthony , K M , Langdon , P G & Torres , L C 2016 , ' Diploptene δ 13 C values from contemporary thermokarst lake sediments show complex spatial variation ' , Biogeosciences , vol. 13 , no. 8 , pp. 2611-2621 . https://doi.org/10.5194/bg-13-2611-2016 |
op_relation |
https://research-information.bris.ac.uk/en/publications/976c3e92-2180-4387-8cde-999641c55a4a |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-13-2611-2016 |
container_title |
Biogeosciences |
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13 |
container_issue |
8 |
container_start_page |
2611 |
op_container_end_page |
2621 |
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1796932862940807168 |