Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming ...

• Main Authors: Meyer, Vera D., Hefter, Jens, Köhler, Peter, Tiedemann, Ralf, Gersonde, Rainer, Wacker, Lukas, Mollenhauer, Gesine
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2019
• Subjects: deglaciation; permafrost decomposition; Beringia; Bering Sea; biomarker; atmospheric CO2; Northwest Pacific; permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000358953; http://hdl.handle.net/20.500.11850/358953

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 CO2 and also to the declining atmospheric radiocarbon contents (Δ14C). 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 ... : Environmental Research Letters, 14 (8) ...