Peter U. Clark has been a researcher in the Department of Geosciences at Oregon State University since 1988. He specializes in glacial geography, quaternary stratigraphy and paleoclimatology. Mr Clark focuses his research more specifically on the history and dynamics of former glaciers and ice sheets, and more generally on paleoclimatology. He approches problems from a variety of perspectives including geochemistry, geophysics and numerical modeling. His research has led him to publish a number of articles in several prestigious magazines, including “Nature and Science”. Mr Clark’s latest work has focused on geochemical studies of freshwater during the Younger Dryas period.