Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf
The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane ( CH 4 ) to the shallow coastal ocean...
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ftdoajarticles:oai:doaj.org/article:b55f466177e24ecb8508bbbf609e03ad 2023-05-15T14:58:08+02:00 Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf M. Puglini V. Brovkin P. Regnier S. Arndt 2020-06-01T00:00:00Z https://doi.org/10.5194/bg-17-3247-2020 https://doaj.org/article/b55f466177e24ecb8508bbbf609e03ad EN eng Copernicus Publications https://www.biogeosciences.net/17/3247/2020/bg-17-3247-2020.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-17-3247-2020 1726-4170 1726-4189 https://doaj.org/article/b55f466177e24ecb8508bbbf609e03ad Biogeosciences, Vol 17, Pp 3247-3275 (2020) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/bg-17-3247-2020 2022-12-31T01:25:36Z The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane ( CH 4 ) to the shallow coastal ocean and ultimately the atmosphere. However, a major unknown in assessing the contribution of this CH 4 flux to the global CH 4 cycle and its climate feedbacks is the fate of CH 4 as it migrates towards the sediment–water interface. In marine sediments, (an)aerobic oxidation reactions generally act as a very efficient methane sink. However, a number of environmental conditions can reduce the efficiency of this biofilter. Here, we used a reaction-transport model to assess the efficiency of the benthic methane filter and, thus, the potential for benthic methane escape across a wide range of environmental conditions that could be encountered on the East Siberian Arctic Shelf. Results show that, under steady-state conditions, anaerobic oxidation of methane (AOM) acts as an efficient biofilter. However, high CH 4 escape is simulated for rapidly accumulating and/or active sediments and can be further enhanced by the presence of organic matter with intermediate reactivity and/or intense local transport processes, such as bioirrigation. In addition, in active settings, the sudden onset of CH 4 flux triggered by, for instance, permafrost thaw or hydrate destabilization can also drive a high non-turbulent methane escape of up to 19 µ mol CH 4 cm −2 yr −1 during a transient, multi-decadal period. This “window of opportunity” arises due to delayed response of the resident microbial community to suddenly changing CH 4 fluxes. A first-order estimate of non-turbulent, benthic methane efflux from the Laptev Sea is derived as well. We find that, under present-day conditions, non-turbulent methane efflux from Laptev Sea sediments does not exceed 1 Gg CH 4 yr −1 . As a consequence, we conclude that previously published estimates of ... Article in Journal/Newspaper Arctic Global warming laptev Laptev Sea permafrost Directory of Open Access Journals: DOAJ Articles Arctic Laptev Sea Biogeosciences 17 12 3247 3275 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 M. Puglini V. Brovkin P. Regnier S. Arndt Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The East Siberian Arctic Shelf (ESAS) hosts large yet poorly quantified reservoirs of subsea permafrost and associated gas hydrates. It has been suggested that the global-warming induced thawing and dissociation of these reservoirs is currently releasing methane ( CH 4 ) to the shallow coastal ocean and ultimately the atmosphere. However, a major unknown in assessing the contribution of this CH 4 flux to the global CH 4 cycle and its climate feedbacks is the fate of CH 4 as it migrates towards the sediment–water interface. In marine sediments, (an)aerobic oxidation reactions generally act as a very efficient methane sink. However, a number of environmental conditions can reduce the efficiency of this biofilter. Here, we used a reaction-transport model to assess the efficiency of the benthic methane filter and, thus, the potential for benthic methane escape across a wide range of environmental conditions that could be encountered on the East Siberian Arctic Shelf. Results show that, under steady-state conditions, anaerobic oxidation of methane (AOM) acts as an efficient biofilter. However, high CH 4 escape is simulated for rapidly accumulating and/or active sediments and can be further enhanced by the presence of organic matter with intermediate reactivity and/or intense local transport processes, such as bioirrigation. In addition, in active settings, the sudden onset of CH 4 flux triggered by, for instance, permafrost thaw or hydrate destabilization can also drive a high non-turbulent methane escape of up to 19 µ mol CH 4 cm −2 yr −1 during a transient, multi-decadal period. This “window of opportunity” arises due to delayed response of the resident microbial community to suddenly changing CH 4 fluxes. A first-order estimate of non-turbulent, benthic methane efflux from the Laptev Sea is derived as well. We find that, under present-day conditions, non-turbulent methane efflux from Laptev Sea sediments does not exceed 1 Gg CH 4 yr −1 . As a consequence, we conclude that previously published estimates of ... |
format |
Article in Journal/Newspaper |
author |
M. Puglini V. Brovkin P. Regnier S. Arndt |
author_facet |
M. Puglini V. Brovkin P. Regnier S. Arndt |
author_sort |
M. Puglini |
title |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_short |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_full |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_fullStr |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_full_unstemmed |
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf |
title_sort |
assessing the potential for non-turbulent methane escape from the east siberian arctic shelf |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-17-3247-2020 https://doaj.org/article/b55f466177e24ecb8508bbbf609e03ad |
geographic |
Arctic Laptev Sea |
geographic_facet |
Arctic Laptev Sea |
genre |
Arctic Global warming laptev Laptev Sea permafrost |
genre_facet |
Arctic Global warming laptev Laptev Sea permafrost |
op_source |
Biogeosciences, Vol 17, Pp 3247-3275 (2020) |
op_relation |
https://www.biogeosciences.net/17/3247/2020/bg-17-3247-2020.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-17-3247-2020 1726-4170 1726-4189 https://doaj.org/article/b55f466177e24ecb8508bbbf609e03ad |
op_doi |
https://doi.org/10.5194/bg-17-3247-2020 |
container_title |
Biogeosciences |
container_volume |
17 |
container_issue |
12 |
container_start_page |
3247 |
op_container_end_page |
3275 |
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1766330233010520064 |