University of Minnesota Duluth
University of Minnesota Department of Chemistry and Biochemistry
Home > Current Seminar

Friday, October 13, 2017; 3:00 p.m.; LSci 175


Department of Chemistry & Biochemistry Welcomes:

Dr. John Kessler
Associate Professor, Department of Earth and Environmental Science,
University of Rochester

“Investigations of Methane Dynamics on the Great Lakes System”


Freshwater environments are substantial sources of methane to the atmosphere, rivaling some of the man-made emissions of this potent greenhouse gas.  Numerous sources of this methane can exist in freshwaters enhancing the atmospheric emission.  However, an equally aggressive set of removal mechanisms can prevent this methane from ever reaching the atmosphere.  Despite the Great Lakes being the largest continuous liquid freshwater environment on the planet, relatively few measurements have been made of the methane sources, sinks, and fluxes in this system.  This presentation will discuss our ongoing work on the Great Lakes, where samples and data were collected during 2016 and 2017 on Lake Superior, Lake Michigan, and Lake Ontario.  The primary goal of this work is to constrain the distribution methane in this environment as well as the processes controlling its sources and fluxes.  Recognizing the enormity of this ongoing task, our supporting goal was to develop and validate the analytical chemistry instrumentation necessary to make these measurements continuously while on the water, enabling a more efficient and effective collection of data.  This presentation will conclude with a discussion of the biochemical process likely responsible for the methane emissions measured to date in this environment and our attempts to extrapolate these measurements using satellite derived chlorophyll data.