Professor Wysession’s research in seismology has primarily involved the computer modeling and interpretation of seismic data for Earth structure, addressing questions of Earth composition and dynamics. Areas of focus have been core-mantle boundary region structure and dynamics, core structure, physical causes of mantle and crustal attenuation, causes of intraplate volcanism and seismicity, and the forensic identification of seismic sources such as nuclear tests and military operations. He is the first geologist to map the Earth’s core-mantle boundary, some 2,000 miles below our feet. His research has been supported by 22 NSF grants, as well as funding from the Packard, Kemper, Lilly, and Pew Foundations.