Clumped isotopes link older carbon substrates with slower rates of methanogenesis in northern lakes

Data on clumped isotope values, radiocarbon content (Fm and ¹⁴C years), and estimated flux for ebullition methane samples from a set of 8 northern lakes in Sweden and Alaska. Additionally, data on clumped isotope values on a set of pure and enrichment culture experiments used to evaluate the effects of methane production rate on clumped isotope values. Lake samples were collected from bubble traps. 'Measurement methods and other details will be published in Douglas et al., Clumped isotopes link older carbon substrates with slower rates of methanogenesis in northern lakes, in press for Geophysical Research Letters (available online).