Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway
Source at http://doi.org/10.1002/2016GC006296 A manuscript version of this article was part of Simone Sauer's doctoral thesis, which is available in Munin at http://hdl.handle.net/10037/9548 To better understand the present and past carbon cycling and transformation processes in methane-influen...
Published in: | Geochemistry, Geophysics, Geosystems |
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American Geophysical Union (AGU)
2016
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Online Access: | https://hdl.handle.net/10037/10912 https://doi.org/10.1002/2016GC006296 |
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ftunivtroemsoe:oai:munin.uit.no:10037/10912 2023-05-15T14:27:35+02:00 Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway Sauer, Simone Hong, Wei-Li Knies, Jochen Lepland, Aivo Forwick, Matthias Klug, Martin Eichinger, Florian Baranwal, Soma Cremiere, Antoine Chand, Shyam Schubert, Carsten J. 2016-10-22 https://hdl.handle.net/10037/10912 https://doi.org/10.1002/2016GC006296 eng eng American Geophysical Union (AGU) Geochemistry Geophysics Geosystems info:eu-repo/grantAgreement/RCN/PETROMAKS2/255150/Norway/Norwegian margin fluid systems and methane- derived carbonate crusts - Recent scientific advances in service of petroleum exploration// info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Sauer, S. et.al.: Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway. Geochemistry Geophysics Geosystems, 2016;17(10):4011-4031 FRIDAID 1392123 doi:10.1002/2016GC006296 1525-2027 https://hdl.handle.net/10037/10912 openAccess VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466 VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466 Journal article Tidsskriftartikkel Peer reviewed 2016 ftunivtroemsoe https://doi.org/10.1002/2016GC006296 2021-06-25T17:55:13Z Source at http://doi.org/10.1002/2016GC006296 A manuscript version of this article was part of Simone Sauer's doctoral thesis, which is available in Munin at http://hdl.handle.net/10037/9548 To better understand the present and past carbon cycling and transformation processes in methane-influenced fjord and shelf areas of northern Norway, we compared two sediment cores from the Hola trough and from Ullsfjorden. We investigated (1) the organic matter composition and sedimentological characteristics to study the sources of organic carbon (C org ) and the factors influencing C org burial, (2) pore water geochemistry to determine the contribution of organoclastic sulfate reduction and methanogenesis to total organic carbon turnover, and (3) the carbon isotopic signature of hydrocarbons to identify the carbon transformation processes and gas sources. High sedimentation and C org accumulation rates in Ullsfjorden support the notion that fjords are important C org sinks. The depth of the sulfate-methanetransition (SMT) in the fjord is controlled by the supply of predominantly marine organic matter to the sediment. Organoclastic sulfate reduction accounts for 60% of the total depth-integrated sulfate reduction in the fjord. In spite of the presence of ethane, propane, and butane, we suggest a purely microbial origin of light hydrocarbons in the sediments based on their low δ 13 C values. In the Hola trough, sedimentation and C org accumulation rates changed during the deglacial-to-post-glacial transition from approximately 80 cm ka -1 to erosion at present. Thus, C org burial in this part of the shelf is presently absent. Low organic matter content in the sediment and low rates of organoclastic sulfate reduction (only 3% of total depth-integrated sulfate reduction) entail that the shallow depth of the SMT is controlled mostly by ascending thermogenic methane from deeper sources. Article in Journal/Newspaper Arctic Northern Norway University of Tromsø: Munin Open Research Archive Norway Geochemistry, Geophysics, Geosystems 17 10 4011 4031 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466 VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466 VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466 Sauer, Simone Hong, Wei-Li Knies, Jochen Lepland, Aivo Forwick, Matthias Klug, Martin Eichinger, Florian Baranwal, Soma Cremiere, Antoine Chand, Shyam Schubert, Carsten J. Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466 VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466 |
description |
Source at http://doi.org/10.1002/2016GC006296 A manuscript version of this article was part of Simone Sauer's doctoral thesis, which is available in Munin at http://hdl.handle.net/10037/9548 To better understand the present and past carbon cycling and transformation processes in methane-influenced fjord and shelf areas of northern Norway, we compared two sediment cores from the Hola trough and from Ullsfjorden. We investigated (1) the organic matter composition and sedimentological characteristics to study the sources of organic carbon (C org ) and the factors influencing C org burial, (2) pore water geochemistry to determine the contribution of organoclastic sulfate reduction and methanogenesis to total organic carbon turnover, and (3) the carbon isotopic signature of hydrocarbons to identify the carbon transformation processes and gas sources. High sedimentation and C org accumulation rates in Ullsfjorden support the notion that fjords are important C org sinks. The depth of the sulfate-methanetransition (SMT) in the fjord is controlled by the supply of predominantly marine organic matter to the sediment. Organoclastic sulfate reduction accounts for 60% of the total depth-integrated sulfate reduction in the fjord. In spite of the presence of ethane, propane, and butane, we suggest a purely microbial origin of light hydrocarbons in the sediments based on their low δ 13 C values. In the Hola trough, sedimentation and C org accumulation rates changed during the deglacial-to-post-glacial transition from approximately 80 cm ka -1 to erosion at present. Thus, C org burial in this part of the shelf is presently absent. Low organic matter content in the sediment and low rates of organoclastic sulfate reduction (only 3% of total depth-integrated sulfate reduction) entail that the shallow depth of the SMT is controlled mostly by ascending thermogenic methane from deeper sources. |
format |
Article in Journal/Newspaper |
author |
Sauer, Simone Hong, Wei-Li Knies, Jochen Lepland, Aivo Forwick, Matthias Klug, Martin Eichinger, Florian Baranwal, Soma Cremiere, Antoine Chand, Shyam Schubert, Carsten J. |
author_facet |
Sauer, Simone Hong, Wei-Li Knies, Jochen Lepland, Aivo Forwick, Matthias Klug, Martin Eichinger, Florian Baranwal, Soma Cremiere, Antoine Chand, Shyam Schubert, Carsten J. |
author_sort |
Sauer, Simone |
title |
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
title_short |
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
title_full |
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
title_fullStr |
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
title_full_unstemmed |
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway |
title_sort |
sources and turnover of organic carbon and methane in fjord and shelf sediments off northern norway |
publisher |
American Geophysical Union (AGU) |
publishDate |
2016 |
url |
https://hdl.handle.net/10037/10912 https://doi.org/10.1002/2016GC006296 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Arctic Northern Norway |
genre_facet |
Arctic Northern Norway |
op_relation |
Geochemistry Geophysics Geosystems info:eu-repo/grantAgreement/RCN/PETROMAKS2/255150/Norway/Norwegian margin fluid systems and methane- derived carbonate crusts - Recent scientific advances in service of petroleum exploration// info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Sauer, S. et.al.: Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway. Geochemistry Geophysics Geosystems, 2016;17(10):4011-4031 FRIDAID 1392123 doi:10.1002/2016GC006296 1525-2027 https://hdl.handle.net/10037/10912 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1002/2016GC006296 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
17 |
container_issue |
10 |
container_start_page |
4011 |
op_container_end_page |
4031 |
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1766301387247845376 |