Geoffrey Ellis is a research geologist and the project chief of the Potential for Geologic Hydrogen Gas Resources project within the Energy Resources Program (ERP) of the U.S. Geological Survey. He is also an affiliated faculty member in the Department of Geology and Geological Engineering at the Colorado School of Mines and the chair of the Hydrogen Resources and Storage Committee within the Energy Minerals Division of the American Association of Petroleum Geologists.

He holds a bachelor’s degree in geological sciences from Cornell University, a master’s degree in geochemistry from the Colorado School of Mines, and a doctorate in marine geology and geophysics from the University of Miami. Prior to joining the ERP, he worked as a staff scientist in the Division of Chemistry and Chemical Engineering at the California Institute of Technology, as a research chemist in the Water Resources Division of the U.S. Geological Survey, and as a consultant in environmental and resource exploration geochemistry. His research interests include organic-inorganic interactions in geologic settings, gas isotope geochemistry, and the potential for natural hydrogen resources.