Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska
As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes...
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Copernicus Publications
2018
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Online Access: | https://doi.org/10.5194/bg-15-6033-2018 https://doaj.org/article/18cbbbe8d5bb491eb967116263dc98c9 |
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ftdoajarticles:oai:doaj.org/article:18cbbbe8d5bb491eb967116263dc98c9 2023-05-15T15:17:11+02:00 Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska L. L. Jongejans J. Strauss J. Lenz F. Peterse K. Mangelsdorf M. Fuchs G. Grosse 2018-10-01T00:00:00Z https://doi.org/10.5194/bg-15-6033-2018 https://doaj.org/article/18cbbbe8d5bb491eb967116263dc98c9 EN eng Copernicus Publications https://www.biogeosciences.net/15/6033/2018/bg-15-6033-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-6033-2018 1726-4170 1726-4189 https://doaj.org/article/18cbbbe8d5bb491eb967116263dc98c9 Biogeosciences, Vol 15, Pp 6033-6048 (2018) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/bg-15-6033-2018 2022-12-31T05:33:02Z As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the belowground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kg m −3 ) compared to the DTLB (35 kg m −3 ) and yedoma deposits (8 kg m −3 ), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indicates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous ... Article in Journal/Newspaper Arctic Ice permafrost Thermokarst Alaska Directory of Open Access Journals: DOAJ Articles Arctic Baldwin ENVELOPE(163.300,163.300,-72.250,-72.250) Biogeosciences 15 20 6033 6048 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 L. L. Jongejans J. Strauss J. Lenz F. Peterse K. Mangelsdorf M. Fuchs G. Grosse Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the belowground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kg m −3 ) compared to the DTLB (35 kg m −3 ) and yedoma deposits (8 kg m −3 ), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indicates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous ... |
format |
Article in Journal/Newspaper |
author |
L. L. Jongejans J. Strauss J. Lenz F. Peterse K. Mangelsdorf M. Fuchs G. Grosse |
author_facet |
L. L. Jongejans J. Strauss J. Lenz F. Peterse K. Mangelsdorf M. Fuchs G. Grosse |
author_sort |
L. L. Jongejans |
title |
Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
title_short |
Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
title_full |
Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
title_fullStr |
Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
title_full_unstemmed |
Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska |
title_sort |
organic matter characteristics in yedoma and thermokarst deposits on baldwin peninsula, west alaska |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-15-6033-2018 https://doaj.org/article/18cbbbe8d5bb491eb967116263dc98c9 |
long_lat |
ENVELOPE(163.300,163.300,-72.250,-72.250) |
geographic |
Arctic Baldwin |
geographic_facet |
Arctic Baldwin |
genre |
Arctic Ice permafrost Thermokarst Alaska |
genre_facet |
Arctic Ice permafrost Thermokarst Alaska |
op_source |
Biogeosciences, Vol 15, Pp 6033-6048 (2018) |
op_relation |
https://www.biogeosciences.net/15/6033/2018/bg-15-6033-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-6033-2018 1726-4170 1726-4189 https://doaj.org/article/18cbbbe8d5bb491eb967116263dc98c9 |
op_doi |
https://doi.org/10.5194/bg-15-6033-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
20 |
container_start_page |
6033 |
op_container_end_page |
6048 |
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1766347454328864768 |