Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard)
The recent discovery of methane seeps in the Arctic region requires a better understanding of the fate of methane in marine sediments if we are to understand the contributions of methane to Arctic ecosystems and climate change. To this goal, we analyze pore water data from five sites along eastern V...
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Language: | English |
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ftsouthampton:oai:eprints.soton.ac.uk:394381 2023-08-27T04:07:47+02:00 Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) Hong, Wei-Li Sauer, Simone Panieri, Giuliana Ambrose, William G. James, Rachael H. Plaza-Faverola, Andreia Schneider, Andrea 2016-11-18 https://eprints.soton.ac.uk/394381/ English eng Hong, Wei-Li, Sauer, Simone, Panieri, Giuliana, Ambrose, William G., James, Rachael H., Plaza-Faverola, Andreia and Schneider, Andrea (2016) Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard). Limnology and Oceanography, 61 (S1), S324-S343. (doi:10.1002/lno.10299 <http://dx.doi.org/10.1002/lno.10299>). Article PeerReviewed 2016 ftsouthampton https://doi.org/10.1002/lno.10299 2023-08-03T22:21:42Z The recent discovery of methane seeps in the Arctic region requires a better understanding of the fate of methane in marine sediments if we are to understand the contributions of methane to Arctic ecosystems and climate change. To this goal, we analyze pore water data from five sites along eastern Vestnesa Ridge, a sediment drift off-north-west Svalbard, to quantify the consumption of dissolved methane across the sulfate-methane-transition-zone which are 3–5 m below seafloor from the investigated sites. We use transport-reaction models to quantify the hydrology as well as the carbon mass balance in the sediments. Pore water profiles and our model results demonstrate that hydrological, microbial, and geochemical processes/reactions efficiently remove methane carbon from fluid over different time scales. We interpret the nonsteady-state behavior of the first 50–70 cm of our pore water profiles from the active sites as an annual scale downward fluid flow due to a seepage-related pressure imbalance. Such downward flow supplies sulfate which enhances methane consumption through anaerobic oxidation of methane (AOM) within this depth range. Our steady-state modeling confirms the efficiency of AOM in consuming dissolved methane in the upper 0.8–1.2 m of sediments. Based on the phosphate profiles, we estimate that AOM at the active pockmarks may have been operating for the last two to four centuries. Precipitation of authigenic carbonate removes more than a quarter of the dissolved inorganic carbon produced by AOM and fixes it as authigenic carbonate in the sediments, a process that sequestrates methane carbon over geological time. Article in Journal/Newspaper Arctic Climate change Svalbard University of Southampton: e-Prints Soton Arctic Svalbard Limnology and Oceanography 61 S1 S324 S343 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
The recent discovery of methane seeps in the Arctic region requires a better understanding of the fate of methane in marine sediments if we are to understand the contributions of methane to Arctic ecosystems and climate change. To this goal, we analyze pore water data from five sites along eastern Vestnesa Ridge, a sediment drift off-north-west Svalbard, to quantify the consumption of dissolved methane across the sulfate-methane-transition-zone which are 3–5 m below seafloor from the investigated sites. We use transport-reaction models to quantify the hydrology as well as the carbon mass balance in the sediments. Pore water profiles and our model results demonstrate that hydrological, microbial, and geochemical processes/reactions efficiently remove methane carbon from fluid over different time scales. We interpret the nonsteady-state behavior of the first 50–70 cm of our pore water profiles from the active sites as an annual scale downward fluid flow due to a seepage-related pressure imbalance. Such downward flow supplies sulfate which enhances methane consumption through anaerobic oxidation of methane (AOM) within this depth range. Our steady-state modeling confirms the efficiency of AOM in consuming dissolved methane in the upper 0.8–1.2 m of sediments. Based on the phosphate profiles, we estimate that AOM at the active pockmarks may have been operating for the last two to four centuries. Precipitation of authigenic carbonate removes more than a quarter of the dissolved inorganic carbon produced by AOM and fixes it as authigenic carbonate in the sediments, a process that sequestrates methane carbon over geological time. |
format |
Article in Journal/Newspaper |
author |
Hong, Wei-Li Sauer, Simone Panieri, Giuliana Ambrose, William G. James, Rachael H. Plaza-Faverola, Andreia Schneider, Andrea |
spellingShingle |
Hong, Wei-Li Sauer, Simone Panieri, Giuliana Ambrose, William G. James, Rachael H. Plaza-Faverola, Andreia Schneider, Andrea Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
author_facet |
Hong, Wei-Li Sauer, Simone Panieri, Giuliana Ambrose, William G. James, Rachael H. Plaza-Faverola, Andreia Schneider, Andrea |
author_sort |
Hong, Wei-Li |
title |
Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
title_short |
Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
title_full |
Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
title_fullStr |
Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
title_full_unstemmed |
Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard) |
title_sort |
removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern vestnesa ridge (svalbard) |
publishDate |
2016 |
url |
https://eprints.soton.ac.uk/394381/ |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
Arctic Climate change Svalbard |
genre_facet |
Arctic Climate change Svalbard |
op_relation |
Hong, Wei-Li, Sauer, Simone, Panieri, Giuliana, Ambrose, William G., James, Rachael H., Plaza-Faverola, Andreia and Schneider, Andrea (2016) Removal of methane through hydrological, microbial, and geochemical processes in the shallow sediments of pockmarks along eastern Vestnesa Ridge (Svalbard). Limnology and Oceanography, 61 (S1), S324-S343. (doi:10.1002/lno.10299 <http://dx.doi.org/10.1002/lno.10299>). |
op_doi |
https://doi.org/10.1002/lno.10299 |
container_title |
Limnology and Oceanography |
container_volume |
61 |
container_issue |
S1 |
container_start_page |
S324 |
op_container_end_page |
S343 |
_version_ |
1775348503254401024 |