Dr. Xie’s research covers both earthquake seismology and applied seismology. For works in earthquake seismology, Dr. Xie is investigating regional seismic wave excitation and propagations with numerical simulations. He is also using broadband digital seismic data to investigate regional tectonics and characteristics of seismic sources including earthquakes and underground nuclear explosions. The works in applied seismology focus on developing novel methods for seismic modeling and imaging, seismic velocity inversion and related resolution analysis.