Organic matter composition and greenhouse gas production of thawing subsea permafrost in the Laptev Sea
(2022) In Nature Communications 13(1).- Abstract
Subsea permafrost represents a large carbon pool that might be or become a significant greenhouse gas source. Scarcity of observational data causes large uncertainties. We here use five 21-56 m long subsea permafrost cores from the Laptev Sea to constrain organic carbon (OC) storage and sources, degradation state and potential greenhouse gas production upon thaw. Grain sizes, optically-stimulated luminescence and biomarkers suggest deposition of aeolian silt and fluvial sand over 160 000 years, with dominant fluvial/alluvial deposition of forest- and tundra-derived organic matter. We estimate an annual thaw rate of 1.3 ± 0.6 kg OC m−2 in subsea permafrost in the area, nine-fold exceeding organic carbon thaw rates for... (More)
Subsea permafrost represents a large carbon pool that might be or become a significant greenhouse gas source. Scarcity of observational data causes large uncertainties. We here use five 21-56 m long subsea permafrost cores from the Laptev Sea to constrain organic carbon (OC) storage and sources, degradation state and potential greenhouse gas production upon thaw. Grain sizes, optically-stimulated luminescence and biomarkers suggest deposition of aeolian silt and fluvial sand over 160 000 years, with dominant fluvial/alluvial deposition of forest- and tundra-derived organic matter. We estimate an annual thaw rate of 1.3 ± 0.6 kg OC m−2 in subsea permafrost in the area, nine-fold exceeding organic carbon thaw rates for terrestrial permafrost. During 20-month incubations, CH4 and CO2 production averaged 1.7 nmol and 2.4 µmol g−1 OC d−1, providing a baseline to assess the contribution of subsea permafrost to the high CH4 fluxes and strong ocean acidification observed in the region.
(Less)
- author
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nature Communications
- volume
- 13
- issue
- 1
- article number
- 5057
- publisher
- Nature Publishing Group
- external identifiers
-
- pmid:36030269
- scopus:85137134627
- ISSN
- 2041-1723
- DOI
- 10.1038/s41467-022-32696-0
- language
- English
- LU publication?
- yes
- id
- 20c85a05-89b3-4160-b766-71952d076e86
- date added to LUP
- 2022-11-09 15:21:19
- date last changed
- 2024-09-20 00:18:48
@article{20c85a05-89b3-4160-b766-71952d076e86, abstract = {{<p>Subsea permafrost represents a large carbon pool that might be or become a significant greenhouse gas source. Scarcity of observational data causes large uncertainties. We here use five 21-56 m long subsea permafrost cores from the Laptev Sea to constrain organic carbon (OC) storage and sources, degradation state and potential greenhouse gas production upon thaw. Grain sizes, optically-stimulated luminescence and biomarkers suggest deposition of aeolian silt and fluvial sand over 160 000 years, with dominant fluvial/alluvial deposition of forest- and tundra-derived organic matter. We estimate an annual thaw rate of 1.3 ± 0.6 kg OC m<sup>−2</sup> in subsea permafrost in the area, nine-fold exceeding organic carbon thaw rates for terrestrial permafrost. During 20-month incubations, CH<sub>4</sub> and CO<sub>2</sub> production averaged 1.7 nmol and 2.4 µmol g<sup>−1</sup> OC d<sup>−1</sup>, providing a baseline to assess the contribution of subsea permafrost to the high CH<sub>4</sub> fluxes and strong ocean acidification observed in the region.</p>}}, author = {{Wild, Birgit and Shakhova, Natalia and Dudarev, Oleg and Ruban, Alexey and Kosmach, Denis and Tumskoy, Vladimir and Tesi, Tommaso and Grimm, Hanna and Nybom, Inna and Matsubara, Felipe and Alexanderson, Helena and Jakobsson, Martin and Mazurov, Alexey and Semiletov, Igor and Gustafsson, Örjan}}, issn = {{2041-1723}}, language = {{eng}}, number = {{1}}, publisher = {{Nature Publishing Group}}, series = {{Nature Communications}}, title = {{Organic matter composition and greenhouse gas production of thawing subsea permafrost in the Laptev Sea}}, url = {{http://dx.doi.org/10.1038/s41467-022-32696-0}}, doi = {{10.1038/s41467-022-32696-0}}, volume = {{13}}, year = {{2022}}, }