Permafrost Carbon and CO2 Pathways Differ at Contrasting Coastal Erosion Sites in the Canadian Arctic ...

• Main Authors: Tanski, George, Bröder, Lisa, Wagner, Dirk, Knoblauch, Christian, Lantuit, Hugues, Beer, Christian, Sachs, Torsten, Fritz, Michael, Tesi, Tommaso, Koch, Boris P., Haghipour, Negar, Eglinton, Timothy I., Strauss, Jens, Vonk, Jorien E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2021
• Subjects: Arctic; coastal erosion; carbon cycling; biogeochemistry; greenhouse gases; carbon dioxide; biomarkers; Herschel Island; permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000479147; http://hdl.handle.net/20.500.11850/479147

Warming air and sea temperatures, longer open-water seasons and sea-level rise collectively promote the erosion of permafrost coasts in the Arctic, which profoundly impacts organic matter pathways. Although estimates on organic carbon (OC) fluxes from erosion exist for some parts of the Arctic, little is known about how much OC is transformed into greenhouse gases (GHGs). In this study we investigated two different coastal erosion scenarios on Qikiqtaruk – Herschel Island (Canada) and estimate the potential for GHG formation. We distinguished between a delayed release represented by mud debris draining a coastal thermoerosional feature and a direct release represented by cliff debris at a low collapsing bluff. Carbon dioxide (CO2) production was measured during incubations at 4°C under aerobic conditions for two months and were modeled for four months and a full year. Our incubation results show that mud debris and cliff debris lost a considerable amount of OC as CO2 (2.5 ± 0.2 and 1.6 ± 0.3% of OC, ... : Frontiers in Earth Science, 9 ...