Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources
The Mackenzie River delta is the second largest Arctic river delta in the world. Thin and destabilizing permafrost coupled with vast natural gas reserves at depth, high organic-content soils, and a high proportion of wetlands create a unique ecosystem conducive to high rates of methane (CH4) emissio...
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2023
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5024141 2024-01-21T10:04:02+01:00 Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources Wesley, D. Dallimore, S. MacLeod, R. Sachs, T. Risk, D. 2023 application/pdf https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141_1/component/file_5024305/5024141.pdf eng eng info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-17-5283-2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141_1/component/file_5024305/5024141.pdf info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ The Cryosphere info:eu-repo/semantics/article 2023 ftgfzpotsdam https://doi.org/10.5194/tc-17-5283-2023 2023-12-25T00:44:23Z The Mackenzie River delta is the second largest Arctic river delta in the world. Thin and destabilizing permafrost coupled with vast natural gas reserves at depth, high organic-content soils, and a high proportion of wetlands create a unique ecosystem conducive to high rates of methane (CH4) emission from biogenic and thermogenic sources. Hotspots are known to have a significant contribution to summertime CH4 emissions in the region. Still, little research has been done to determine how often geologic or biogenic CH4 contributes to hotspots in the Mackenzie River delta. In the present study, stable carbon isotope analysis was used to identify the source of CH4 at several aquatic and terrestrial sites thought to be hotspots of CH4 flux to the atmosphere. Walking transects and point samples of atmospheric CH4 and CO2 concentrations were measured. Source stable carbon isotope (δ13C-CH4) signatures were derived from keeling plots of point samples and ranged from −42 ‰ to −88 ‰ δ13C-CH4, identifying both biogenic and thermogenic sources. A CH4 source was determined for eight hotspots, two of which were thermogenic in origin (−42.5 ‰, −44.7 ‰), four of which were biogenic in origin (−71.9 ‰ to −88.3 ‰), and two of which may have been produced by the oxidation of biogenic CH4 (−53.0 ‰, −63.6 ‰), as evidenced by δ13C-CH4 signatures. This indicates that the largest hotspots of CH4 production in the Mackenzie River delta are caused by a variety of sources. Article in Journal/Newspaper Arctic Mackenzie river permafrost The Cryosphere GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Arctic Mackenzie River The Cryosphere 17 12 5283 5297 |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
The Mackenzie River delta is the second largest Arctic river delta in the world. Thin and destabilizing permafrost coupled with vast natural gas reserves at depth, high organic-content soils, and a high proportion of wetlands create a unique ecosystem conducive to high rates of methane (CH4) emission from biogenic and thermogenic sources. Hotspots are known to have a significant contribution to summertime CH4 emissions in the region. Still, little research has been done to determine how often geologic or biogenic CH4 contributes to hotspots in the Mackenzie River delta. In the present study, stable carbon isotope analysis was used to identify the source of CH4 at several aquatic and terrestrial sites thought to be hotspots of CH4 flux to the atmosphere. Walking transects and point samples of atmospheric CH4 and CO2 concentrations were measured. Source stable carbon isotope (δ13C-CH4) signatures were derived from keeling plots of point samples and ranged from −42 ‰ to −88 ‰ δ13C-CH4, identifying both biogenic and thermogenic sources. A CH4 source was determined for eight hotspots, two of which were thermogenic in origin (−42.5 ‰, −44.7 ‰), four of which were biogenic in origin (−71.9 ‰ to −88.3 ‰), and two of which may have been produced by the oxidation of biogenic CH4 (−53.0 ‰, −63.6 ‰), as evidenced by δ13C-CH4 signatures. This indicates that the largest hotspots of CH4 production in the Mackenzie River delta are caused by a variety of sources. |
format |
Article in Journal/Newspaper |
author |
Wesley, D. Dallimore, S. MacLeod, R. Sachs, T. Risk, D. |
spellingShingle |
Wesley, D. Dallimore, S. MacLeod, R. Sachs, T. Risk, D. Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
author_facet |
Wesley, D. Dallimore, S. MacLeod, R. Sachs, T. Risk, D. |
author_sort |
Wesley, D. |
title |
Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
title_short |
Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
title_full |
Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
title_fullStr |
Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
title_full_unstemmed |
Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
title_sort |
characterization of atmospheric methane release in the outer mackenzie river delta from biogenic and thermogenic sources |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141_1/component/file_5024305/5024141.pdf |
geographic |
Arctic Mackenzie River |
geographic_facet |
Arctic Mackenzie River |
genre |
Arctic Mackenzie river permafrost The Cryosphere |
genre_facet |
Arctic Mackenzie river permafrost The Cryosphere |
op_source |
The Cryosphere |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-17-5283-2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5024141_1/component/file_5024305/5024141.pdf |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.5194/tc-17-5283-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
12 |
container_start_page |
5283 |
op_container_end_page |
5297 |
_version_ |
1788694456075026432 |