Research Interests: I received my formal training in geological oceanography, first as an undergraduate at the University of Washington and then in graduate study at Scripps Institution of Oceanography, with a focus on deep-sea sedimentation and paleoceanography. While I kept one foot in the oceans, I became interested in many aspects of sedimentation in large lakes based on some early experience on Lake Superior, where I applied oceanographic techniques to examine both physical and geochemical processes, ranging from identification of erosional features in the deep, offshore basins caused by strong bottom currents, to the geochemical cycling of silica and carbon. I moved on to other large lake systems, including Issyk Kul in Kyrgyzstan and Lake Nicaragua in Central America, and especially the great lakes of the East African Rift Valley, where I have devoted much of my research career to unraveling the climate history of tropical East Africa based on geochemical analyses of sediment cores. My interest is now shifting towards sustainability of the world’s great lakes as they endure the consequences of a growing human population, expanding agriculture, and climate change.