Concentration and stable carbon and hydrogen isotopes of lipid biomarkers in a thermokarst lake in Arctic Alaska ...

• Main Authors: Elvert, Marcus, Pohlman, John W, Becker, Kevin W, Gaglioti, Benjamin V, Hinrichs, Kai-Uwe, Wooller, Matthew J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2017
• Subjects: Center for Marine Environmental Sciences MARUM; Thermokarst; Alaska
• Online Access: https://dx.doi.org/10.1594/pangaea.873658; https://doi.pangaea.de/10.1594/PANGAEA.873658

Arctic lakes and wetlands contribute a substantial amount of methane to the contemporary atmosphere, yet profound knowledge gaps remain regarding the intensity and climatic control of past methane emissions from this source. In this study, we reconstruct methane turnover and environmental conditions, including estimates of mean annual and summer temperature, from a thermokarst lake (Lake Qalluuraq) on the Arctic Coastal Plain of northern Alaska for the Holocene by using source-specific lipid biomarkers preserved in a radiocarbon-dated sediment core. Our results document a more prominent role for methane in the carbon cycle when the lake basin was an emergent fen habitat between ~12,300 and ~10,000 cal yr BP, a time period closely coinciding with the Holocene Thermal Maximum (HTM) in North Alaska. Enhanced methane turnover was stimulated by relatively warm temperatures, increased moisture, nutrient supply, and primary productivity. After ~10,000 cal yr BP, a thermokarst lake with abundant submerged mosses ... : Supplement to: Elvert, Marcus; Pohlman, John W; Becker, Kevin W; Gaglioti, Benjamin V; Hinrichs, Kai-Uwe; Wooller, Matthew J (2016): Methane turnover and environmental change from Holocene lipid biomarker records in a thermokarst lake in Arctic Alaska. The Holocene, 26(11), 1766-1777 ...