My research interests include probing deep Earth structures with seismic energy and building their relationship with surface processes. We have investigated the mantle transition zone with both source-side converted phases and receiver-side scattering kernel in the past three years. One of our current research plans is to study the focal mechanisms of some volcanic micro-earthquakes beneath Mt. St. Helens with the dense three component array data and try to support an existing source model or come up with a new one. Another proposal is to explore the potential stratification layer near the top of the outer core with underside seismic reflections and derive an idea of the content of concentrated light elements in the area.