The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis
The Arctic Ocean, especially the East Siberian Arctic Shelf (ESAS), has been proposed as a significant source of methane that might play an increasingly important role in the future. However, the underlying processes of formation, removal and transport associated with such emissions are to date stro...
Main Authors: | , , , , , , , , , , , , , |
---|---|
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2017
|
Subjects: | |
Online Access: | https://dspace.library.uu.nl/handle/1874/352446 |
id |
ftunivutrecht:oai:dspace.library.uu.nl:1874/352446 |
---|---|
record_format |
openpolar |
spelling |
ftunivutrecht:oai:dspace.library.uu.nl:1874/352446 2023-07-23T04:17:26+02:00 The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis Sapart, Célia J. Shakhova, Natalia Semiletov, Igor Jansen, Joachim Szidat, Sönke Kosmach, Denis Dudarev, Oleg van der Veen, Carina Egger, M.J. Sergienko, Valentine Salyuk, Anatoly Tumskoy, Vladimir Tison, Jean-Louis Röckmann, Thomas ERC-PHOXY: Phosphorus dynamics in low-oxygen marine systems: quantifying the nutrient-climate connection in Earth’s past, present and future General geochemistry Sub Atmospheric physics and chemistry Sub Algemeen Marine & Atmospheric Res Geochemistry 2017-05-05 image/pdf https://dspace.library.uu.nl/handle/1874/352446 en eng 1726-4170 https://dspace.library.uu.nl/handle/1874/352446 info:eu-repo/semantics/OpenAccess Article 2017 ftunivutrecht 2023-07-02T02:09:57Z The Arctic Ocean, especially the East Siberian Arctic Shelf (ESAS), has been proposed as a significant source of methane that might play an increasingly important role in the future. However, the underlying processes of formation, removal and transport associated with such emissions are to date strongly debated. CH4 concentration and triple isotope composition were analyzed on gas extracted from sediment and water sampled at numerous locations on the shallow ESAS from 2007 to 2013. We find high concentrations (up to 500 µM) of CH4 in the pore water of the partially thawed subsea permafrost of this region. For all sediment cores, both hydrogen and carbon isotope data reveal the predominant occurrence of CH4 that is not of thermogenic origin as it has long been thought, but resultant from microbial CH4 formation. At some locations, meltwater from buried meteoric ice and/or old organic matter preserved in the subsea permafrost were used as substrates. Radiocarbon data demonstrate that the CH4 present in the ESAS sediment is of Pleistocene age or older, but a small contribution of highly 14C-enriched CH4, from unknown origin, prohibits precise age determination for one sediment core and in the water column. Our sediment data suggest that at locations where bubble plumes have been observed, CH4 can escape anaerobic oxidation in the surface sediment. Article in Journal/Newspaper Arctic Arctic Ocean Ice permafrost Utrecht University Repository Arctic Arctic Ocean |
institution |
Open Polar |
collection |
Utrecht University Repository |
op_collection_id |
ftunivutrecht |
language |
English |
description |
The Arctic Ocean, especially the East Siberian Arctic Shelf (ESAS), has been proposed as a significant source of methane that might play an increasingly important role in the future. However, the underlying processes of formation, removal and transport associated with such emissions are to date strongly debated. CH4 concentration and triple isotope composition were analyzed on gas extracted from sediment and water sampled at numerous locations on the shallow ESAS from 2007 to 2013. We find high concentrations (up to 500 µM) of CH4 in the pore water of the partially thawed subsea permafrost of this region. For all sediment cores, both hydrogen and carbon isotope data reveal the predominant occurrence of CH4 that is not of thermogenic origin as it has long been thought, but resultant from microbial CH4 formation. At some locations, meltwater from buried meteoric ice and/or old organic matter preserved in the subsea permafrost were used as substrates. Radiocarbon data demonstrate that the CH4 present in the ESAS sediment is of Pleistocene age or older, but a small contribution of highly 14C-enriched CH4, from unknown origin, prohibits precise age determination for one sediment core and in the water column. Our sediment data suggest that at locations where bubble plumes have been observed, CH4 can escape anaerobic oxidation in the surface sediment. |
author2 |
ERC-PHOXY: Phosphorus dynamics in low-oxygen marine systems: quantifying the nutrient-climate connection in Earth’s past, present and future General geochemistry Sub Atmospheric physics and chemistry Sub Algemeen Marine & Atmospheric Res Geochemistry |
format |
Article in Journal/Newspaper |
author |
Sapart, Célia J. Shakhova, Natalia Semiletov, Igor Jansen, Joachim Szidat, Sönke Kosmach, Denis Dudarev, Oleg van der Veen, Carina Egger, M.J. Sergienko, Valentine Salyuk, Anatoly Tumskoy, Vladimir Tison, Jean-Louis Röckmann, Thomas |
spellingShingle |
Sapart, Célia J. Shakhova, Natalia Semiletov, Igor Jansen, Joachim Szidat, Sönke Kosmach, Denis Dudarev, Oleg van der Veen, Carina Egger, M.J. Sergienko, Valentine Salyuk, Anatoly Tumskoy, Vladimir Tison, Jean-Louis Röckmann, Thomas The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
author_facet |
Sapart, Célia J. Shakhova, Natalia Semiletov, Igor Jansen, Joachim Szidat, Sönke Kosmach, Denis Dudarev, Oleg van der Veen, Carina Egger, M.J. Sergienko, Valentine Salyuk, Anatoly Tumskoy, Vladimir Tison, Jean-Louis Röckmann, Thomas |
author_sort |
Sapart, Célia J. |
title |
The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
title_short |
The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
title_full |
The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
title_fullStr |
The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
title_full_unstemmed |
The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis |
title_sort |
origin of methane in the east siberian arctic shelf unraveled with triple isotope analysis |
publishDate |
2017 |
url |
https://dspace.library.uu.nl/handle/1874/352446 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Ice permafrost |
genre_facet |
Arctic Arctic Ocean Ice permafrost |
op_relation |
1726-4170 https://dspace.library.uu.nl/handle/1874/352446 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772179188579565568 |