My research interest is solid earth geophysics, emphasizing deep and three-dimensionally heterogeneous structure of the earth inferred from seismic wavefields. Some specific areas of my research have included : effects on the seismic wavefield by descending slabs and fault zones, solidification of the inner core and its role in driving the geodynamo, viscoelastic and scattering attenuation of waves in heterogeneous media, and numerical modeling of wavefields by parallel computing.