No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment
Release of carbon from thawing permafrost in high northern latitudes is a potential positive feedback in a warming climate, particularly since large quantities of carbon-rich organic matter have been stored in the permafrost soils for many millennia. Thawing of permafrost is expected to make this an...
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ftawi:oai:epic.awi.de:47529 2023-05-15T15:03:41+02:00 No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment Mollenhauer, Gesine Winterfeld, Maria Hefter, Jens Grotheer, Hendrik Kattein, Laura Pittauer, Daniela 2018-06-21 https://epic.awi.de/id/eprint/47529/ https://hdl.handle.net/10013/epic.a9af56c1-db8a-4df1-9b2b-57fe05587a72 unknown Mollenhauer, G. orcid:0000-0001-5138-564X , Winterfeld, M. , Hefter, J. orcid:0000-0002-5823-1966 , Grotheer, H. orcid:0000-0003-0207-3767 , Kattein, L. and Pittauer, D. orcid:0000-0002-3643-333X (2018) No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment , Radiocarbon 2018, Trondheim, Norway, 17 June 2018 - 22 June 2018 . hdl:10013/epic.a9af56c1-db8a-4df1-9b2b-57fe05587a72 EPIC3Radiocarbon 2018, Trondheim, Norway, 2018-06-17-2018-06-22 Conference notRev 2018 ftawi 2021-12-24T15:43:57Z Release of carbon from thawing permafrost in high northern latitudes is a potential positive feedback in a warming climate, particularly since large quantities of carbon-rich organic matter have been stored in the permafrost soils for many millennia. Thawing of permafrost is expected to make this ancient organic matter bioavailable resulting in increased emissions of greenhouse gases. Thawing of permafrost may also result in increased transport of particulate organic matter through river systems to the ocean, where parts of this organic matter may escape remineralization and will be buried in marine sediments. This process might have accelerated over the past century in a warming Arctic with more frequent thaw slumping and increased river discharge leading to increased mobilization of ancient terrestrial organic matter previously freeze-locked in permafrost. We therefore studied short sediment cores that were recovered off two of the main branches of the Lena River Delta, receiving the suspended matter transported from the mainly permafrost covered catchment of this great Russian Arctic river. The cores were recovered in 2013 from water depths of approximately 15 m and dated using 210Pbxs and 137Cs. The sediment records cover the past 70 to 120 years. By direct combustion of isolated analytes using an elemental analyser (EA) directly coupled to the accelerator mass spectrometer (MICADAS, Ionplus) via a Gas Interface System, we obtained compound-specific radiocarbon ages for a suite of n-alkanoic acids. We studied C16 to C28 even carbon number n-alkanoic acids, a homologous series containing both aquatic (C16 and C18 n-alkanoic acids) and terrigenous (C26 and C28 n-alkanoic acids) biomarkers. Besides, we analysed biomarker concentrations and the geochemical composition of the sediment. Our results reveal that throughout the records’ length, the age at deposition of the terrigenous biomarkers remained constant, while that of the aquatic biomarker decreased in the most recent decades. We will discuss these findings in context of the increases in Lena River discharge observed since the late 1980ies. The results allow estimation of the rapidly cycling biospheric contribution to each biomarker. Conference Object Arctic lena river permafrost Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
Release of carbon from thawing permafrost in high northern latitudes is a potential positive feedback in a warming climate, particularly since large quantities of carbon-rich organic matter have been stored in the permafrost soils for many millennia. Thawing of permafrost is expected to make this ancient organic matter bioavailable resulting in increased emissions of greenhouse gases. Thawing of permafrost may also result in increased transport of particulate organic matter through river systems to the ocean, where parts of this organic matter may escape remineralization and will be buried in marine sediments. This process might have accelerated over the past century in a warming Arctic with more frequent thaw slumping and increased river discharge leading to increased mobilization of ancient terrestrial organic matter previously freeze-locked in permafrost. We therefore studied short sediment cores that were recovered off two of the main branches of the Lena River Delta, receiving the suspended matter transported from the mainly permafrost covered catchment of this great Russian Arctic river. The cores were recovered in 2013 from water depths of approximately 15 m and dated using 210Pbxs and 137Cs. The sediment records cover the past 70 to 120 years. By direct combustion of isolated analytes using an elemental analyser (EA) directly coupled to the accelerator mass spectrometer (MICADAS, Ionplus) via a Gas Interface System, we obtained compound-specific radiocarbon ages for a suite of n-alkanoic acids. We studied C16 to C28 even carbon number n-alkanoic acids, a homologous series containing both aquatic (C16 and C18 n-alkanoic acids) and terrigenous (C26 and C28 n-alkanoic acids) biomarkers. Besides, we analysed biomarker concentrations and the geochemical composition of the sediment. Our results reveal that throughout the records’ length, the age at deposition of the terrigenous biomarkers remained constant, while that of the aquatic biomarker decreased in the most recent decades. We will discuss these findings in context of the increases in Lena River discharge observed since the late 1980ies. The results allow estimation of the rapidly cycling biospheric contribution to each biomarker. |
format |
Conference Object |
author |
Mollenhauer, Gesine Winterfeld, Maria Hefter, Jens Grotheer, Hendrik Kattein, Laura Pittauer, Daniela |
spellingShingle |
Mollenhauer, Gesine Winterfeld, Maria Hefter, Jens Grotheer, Hendrik Kattein, Laura Pittauer, Daniela No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
author_facet |
Mollenhauer, Gesine Winterfeld, Maria Hefter, Jens Grotheer, Hendrik Kattein, Laura Pittauer, Daniela |
author_sort |
Mollenhauer, Gesine |
title |
No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
title_short |
No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
title_full |
No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
title_fullStr |
No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
title_full_unstemmed |
No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment |
title_sort |
no evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the lena river catchment |
publishDate |
2018 |
url |
https://epic.awi.de/id/eprint/47529/ https://hdl.handle.net/10013/epic.a9af56c1-db8a-4df1-9b2b-57fe05587a72 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic lena river permafrost |
genre_facet |
Arctic lena river permafrost |
op_source |
EPIC3Radiocarbon 2018, Trondheim, Norway, 2018-06-17-2018-06-22 |
op_relation |
Mollenhauer, G. orcid:0000-0001-5138-564X , Winterfeld, M. , Hefter, J. orcid:0000-0002-5823-1966 , Grotheer, H. orcid:0000-0003-0207-3767 , Kattein, L. and Pittauer, D. orcid:0000-0002-3643-333X (2018) No evidence for 20th century acceleration in mobilization of fossil carbon from thawing permafrost in the Lena River catchment , Radiocarbon 2018, Trondheim, Norway, 17 June 2018 - 22 June 2018 . hdl:10013/epic.a9af56c1-db8a-4df1-9b2b-57fe05587a72 |
_version_ |
1766335534091730944 |