Lecture, three hours; computer laboratory/discussion, one hour. Requisite: course 1, or any course from 3 through 17, 20, or Clusters 70A. Designed for juniors/seniors in physical sciences. Exploration of history and phenomenology of plate tectonics theory, with particular focus on obervables and kinematics. Evidence supporting plate tectonics theory (magnetic anomalies, seismicity, gravity). Tectonic, igneous, and metamorphic processes at plate boundaries. Focus on plate kinematics both past and present and learn how to compute and plot velocities. Exploration of plate dynamics including driving mechanism and convection. P/NP or letter grading.