My interests lie primarily in exploring various tectonic problems seismologically and gaining better understanding of multi-scale Earth structure from shallow to deep, which includes a wide range of topics such as regional structural kinematics, unusual earthquake sequences, mountain building process, 3-D slab interaction, volcanic plumbing system, and inner core structure. My main technical focus is on improving seismic imaging through multi-dataset joint inversion, waveform inversion, and body-wave seismic interferometry. In the meantime, I also work on earthquake rupture directivity and time-lapse environmental monitoring for earthquake and landslide hazard mitigation.