Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming
Abstract During the last deglaciation (18–8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially...
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Online Access: | http://dx.doi.org/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653/pdf |
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crioppubl:10.1088/1748-9326/ab2653 2024-06-23T07:51:47+00:00 Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming Meyer, Vera D Hefter, Jens Köhler, Peter Tiedemann, Ralf Gersonde, Rainer Wacker, Lukas Mollenhauer, Gesine 2019 http://dx.doi.org/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653/pdf unknown IOP Publishing http://creativecommons.org/licenses/by/3.0/ https://iopscience.iop.org/info/page/text-and-data-mining Environmental Research Letters volume 14, issue 8, page 085003 ISSN 1748-9326 journal-article 2019 crioppubl https://doi.org/10.1088/1748-9326/ab2653 2024-05-27T13:03:28Z Abstract During the last deglaciation (18–8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially contributed to the deglacial rise in atmospheric CO 2 and also to the declining atmospheric radiocarbon contents (Δ 14 C). The significance of permafrost for the atmospheric carbon pool is not well understood as the timing of the carbon activation is poorly constrained by proxy data. Here, we trace the mobilization of organic matter from permafrost in the Pacific sector of Beringia over the last 22 kyr using mass-accumulation rates and radiocarbon signatures of terrigenous biomarkers in four sediment cores from the Bering Sea and the Northwest Pacific. We find that pronounced reworking and thus the vulnerability of old organic carbon to remineralization commenced during the early deglaciation (∼16.8 kyr BP) when meltwater runoff in the Yukon River intensified riverbank erosion of permafrost soils and fluvial discharge. Regional deglaciation in Alaska additionally mobilized significant fractions of fossil, petrogenic organic matter at this time. Permafrost decomposition across Beringia’s Pacific sector occurred in two major pulses that match the Bølling-Allerød and Preboreal warm spells and rapidly initiated within centuries. The carbon mobilization likely resulted from massive shelf flooding during meltwater pulses 1A (∼14.6 kyr BP) and 1B (∼11.5 kyr BP) followed by permafrost thaw in the hinterland. Our findings emphasize that coastal erosion was a major control to rapidly mobilize permafrost carbon along Beringia’s Pacific coast at ∼14.6 and ∼11.5 kyr BP implying that shelf flooding in Beringia may partly explain the centennial-scale rises in atmospheric CO 2 at these times. Around 16.5 kyr BP, the mobilization of old terrigenous organic matter caused by meltwater-floods may have additionally contributed to ... Article in Journal/Newspaper Bering Sea permafrost Yukon river Alaska Beringia Yukon IOP Publishing Bering Sea Pacific Yukon Environmental Research Letters 14 8 085003 |
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Abstract During the last deglaciation (18–8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially contributed to the deglacial rise in atmospheric CO 2 and also to the declining atmospheric radiocarbon contents (Δ 14 C). The significance of permafrost for the atmospheric carbon pool is not well understood as the timing of the carbon activation is poorly constrained by proxy data. Here, we trace the mobilization of organic matter from permafrost in the Pacific sector of Beringia over the last 22 kyr using mass-accumulation rates and radiocarbon signatures of terrigenous biomarkers in four sediment cores from the Bering Sea and the Northwest Pacific. We find that pronounced reworking and thus the vulnerability of old organic carbon to remineralization commenced during the early deglaciation (∼16.8 kyr BP) when meltwater runoff in the Yukon River intensified riverbank erosion of permafrost soils and fluvial discharge. Regional deglaciation in Alaska additionally mobilized significant fractions of fossil, petrogenic organic matter at this time. Permafrost decomposition across Beringia’s Pacific sector occurred in two major pulses that match the Bølling-Allerød and Preboreal warm spells and rapidly initiated within centuries. The carbon mobilization likely resulted from massive shelf flooding during meltwater pulses 1A (∼14.6 kyr BP) and 1B (∼11.5 kyr BP) followed by permafrost thaw in the hinterland. Our findings emphasize that coastal erosion was a major control to rapidly mobilize permafrost carbon along Beringia’s Pacific coast at ∼14.6 and ∼11.5 kyr BP implying that shelf flooding in Beringia may partly explain the centennial-scale rises in atmospheric CO 2 at these times. Around 16.5 kyr BP, the mobilization of old terrigenous organic matter caused by meltwater-floods may have additionally contributed to ... |
format |
Article in Journal/Newspaper |
author |
Meyer, Vera D Hefter, Jens Köhler, Peter Tiedemann, Ralf Gersonde, Rainer Wacker, Lukas Mollenhauer, Gesine |
spellingShingle |
Meyer, Vera D Hefter, Jens Köhler, Peter Tiedemann, Ralf Gersonde, Rainer Wacker, Lukas Mollenhauer, Gesine Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
author_facet |
Meyer, Vera D Hefter, Jens Köhler, Peter Tiedemann, Ralf Gersonde, Rainer Wacker, Lukas Mollenhauer, Gesine |
author_sort |
Meyer, Vera D |
title |
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
title_short |
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
title_full |
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
title_fullStr |
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
title_full_unstemmed |
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming |
title_sort |
permafrost-carbon mobilization in beringia caused by deglacial meltwater runoff, sea-level rise and warming |
publisher |
IOP Publishing |
publishDate |
2019 |
url |
http://dx.doi.org/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653 https://iopscience.iop.org/article/10.1088/1748-9326/ab2653/pdf |
geographic |
Bering Sea Pacific Yukon |
geographic_facet |
Bering Sea Pacific Yukon |
genre |
Bering Sea permafrost Yukon river Alaska Beringia Yukon |
genre_facet |
Bering Sea permafrost Yukon river Alaska Beringia Yukon |
op_source |
Environmental Research Letters volume 14, issue 8, page 085003 ISSN 1748-9326 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ https://iopscience.iop.org/info/page/text-and-data-mining |
op_doi |
https://doi.org/10.1088/1748-9326/ab2653 |
container_title |
Environmental Research Letters |
container_volume |
14 |
container_issue |
8 |
container_start_page |
085003 |
_version_ |
1802642907969093632 |