Remobilization of Old Permafrost Carbon to Chukchi Sea Sediments During the End of the Last Deglaciation.

https://arctichealth.org/en/permalink/ahliterature299553
Source
Global Biogeochem Cycles. 2019 Jan; 33(1):2-14
Publication Type
Journal Article
Date
Jan-2019
Author
Jannik Martens
Birgit Wild
Christof Pearce
Tommaso Tesi
August Andersson
Lisa Bröder
Matt O'Regan
Martin Jakobsson
Martin Sköld
Laura Gemery
Thomas M Cronin
Igor Semiletov
Oleg V Dudarev
Örjan Gustafsson
Author Affiliation
Department of Environmental Science and Analytical Chemistry (ACES) Stockholm University Stockholm Sweden.
Source
Global Biogeochem Cycles. 2019 Jan; 33(1):2-14
Date
Jan-2019
Language
English
Publication Type
Journal Article
Abstract
Climate warming is expected to destabilize permafrost carbon (PF-C) by thaw-erosion and deepening of the seasonally thawed active layer and thereby promote PF-C mineralization to CO2 and CH4. A similar PF-C remobilization might have contributed to the increase in atmospheric CO2 during deglacial warming after the last glacial maximum. Using carbon isotopes and terrestrial biomarkers (?14C, d13C, and lignin phenols), this study quantifies deposition of terrestrial carbon originating from permafrost in sediments from the Chukchi Sea (core SWERUS-L2-4-PC1). The sediment core reconstructs remobilization of permafrost carbon during the late Allerød warm period starting at 13,000 cal years before present (BP), the Younger Dryas, and the early Holocene warming until 11,000 cal years BP and compares this period with the late Holocene, from 3,650 years BP until present. Dual-carbon-isotope-based source apportionment demonstrates that Ice Complex Deposit-ice- and carbon-rich permafrost from the late Pleistocene (also referred to as Yedoma)-was the dominant source of organic carbon (66 ± 8%; mean ± standard deviation) to sediments during the end of the deglaciation, with fluxes more than twice as high (8.0 ± 4.6 g·m-2·year-1) as in the late Holocene (3.1 ± 1.0 g·m-2·year-1). These results are consistent with late deglacial PF-C remobilization observed in a Laptev Sea record, yet in contrast with PF-C sources, which at that location were dominated by active layer material from the Lena River watershed. Release of dormant PF-C from erosion of coastal permafrost during the end of the last deglaciation indicates vulnerability of Ice Complex Deposit in response to future warming and sea level changes.
PubMed ID
31007381 View in PubMed
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