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 (CH 4 ) emiss...
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2023
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Online Access: | https://doi.org/10.5194/tc-17-5283-2023 https://doaj.org/article/e30a8c4c13054025a5272f88f2bb2b0a |
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ftdoajarticles:oai:doaj.org/article:e30a8c4c13054025a5272f88f2bb2b0a 2024-01-14T10:04:55+01:00 Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources D. Wesley S. Dallimore R. MacLeod T. Sachs D. Risk 2023-12-01T00:00:00Z https://doi.org/10.5194/tc-17-5283-2023 https://doaj.org/article/e30a8c4c13054025a5272f88f2bb2b0a EN eng Copernicus Publications https://tc.copernicus.org/articles/17/5283/2023/tc-17-5283-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-5283-2023 1994-0416 1994-0424 https://doaj.org/article/e30a8c4c13054025a5272f88f2bb2b0a The Cryosphere, Vol 17, Pp 5283-5297 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-5283-2023 2023-12-17T01:40:38Z 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 (CH 4 ) emission from biogenic and thermogenic sources. Hotspots are known to have a significant contribution to summertime CH 4 emissions in the region. Still, little research has been done to determine how often geologic or biogenic CH 4 contributes to hotspots in the Mackenzie River delta. In the present study, stable carbon isotope analysis was used to identify the source of CH 4 at several aquatic and terrestrial sites thought to be hotspots of CH 4 flux to the atmosphere. Walking transects and point samples of atmospheric CH 4 and CO 2 concentrations were measured. Source stable carbon isotope ( δ 13 C-CH 4 ) signatures were derived from keeling plots of point samples and ranged from −42 ‰ to −88 ‰ δ 13 C-CH 4 , identifying both biogenic and thermogenic sources. A CH 4 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 CH 4 ( −53.0 ‰ , −63.6 ‰ ), as evidenced by δ 13 C-CH 4 signatures. This indicates that the largest hotspots of CH 4 production in the Mackenzie River delta are caused by a variety of sources. Article in Journal/Newspaper Arctic Mackenzie river permafrost The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic Mackenzie River The Cryosphere 17 12 5283 5297 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 D. Wesley S. Dallimore R. MacLeod T. Sachs D. Risk Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
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 (CH 4 ) emission from biogenic and thermogenic sources. Hotspots are known to have a significant contribution to summertime CH 4 emissions in the region. Still, little research has been done to determine how often geologic or biogenic CH 4 contributes to hotspots in the Mackenzie River delta. In the present study, stable carbon isotope analysis was used to identify the source of CH 4 at several aquatic and terrestrial sites thought to be hotspots of CH 4 flux to the atmosphere. Walking transects and point samples of atmospheric CH 4 and CO 2 concentrations were measured. Source stable carbon isotope ( δ 13 C-CH 4 ) signatures were derived from keeling plots of point samples and ranged from −42 ‰ to −88 ‰ δ 13 C-CH 4 , identifying both biogenic and thermogenic sources. A CH 4 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 CH 4 ( −53.0 ‰ , −63.6 ‰ ), as evidenced by δ 13 C-CH 4 signatures. This indicates that the largest hotspots of CH 4 production in the Mackenzie River delta are caused by a variety of sources. |
format |
Article in Journal/Newspaper |
author |
D. Wesley S. Dallimore R. MacLeod T. Sachs D. Risk |
author_facet |
D. Wesley S. Dallimore R. MacLeod T. Sachs D. Risk |
author_sort |
D. Wesley |
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 |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-5283-2023 https://doaj.org/article/e30a8c4c13054025a5272f88f2bb2b0a |
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, Vol 17, Pp 5283-5297 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/5283/2023/tc-17-5283-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-5283-2023 1994-0416 1994-0424 https://doaj.org/article/e30a8c4c13054025a5272f88f2bb2b0a |
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 |
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1788059350898573312 |