Driven by a fundamental curiosity about processes on Earth and other planets, students in the EAPS Geophysics Program work to understand complicated physical and chemical interactions—occurring over a broad range of spatial and temporal scales—that result in the rich behaviors of a variety of geosystems. We develop advanced tools of observation to address questions such as: What is the pattern of mantle convection and what are the underlying dynamics? How are subcontinental keels created and preserved? How do magmas and deforming host rocks interact? How can microwave signals help us learn more about the distribution of water vapor in the atmosphere?