Image above: Graduate student Louise Farquharson and Katey Walter Anthony sample the refrozen sediments of a deep, drained thermokarst lake..
Photo Credit: Katey Walter Anthony.
Permafrost thaw beneath deep thermokarst lakes leads to large emissions of methane and carbon dioxide to the atmosphere. In turn, these greenhouse gases contribute to global climate warming, which leads to more permafrost thaw in a positive feedback cycle. This talk will uncover sources of methane and CO2 in deep Beringian thermokarst lakes that comes from decay of organic matter from contemporary ecosystems and thawed Pleistocene-aged yedoma permafrost. The talk will also consider the magnitude of atmospheric carbon uptake by the same lakes, and the degree to which this negative feedback process mitigates greenhouse gas emissions.