The earth's lithosphere is generally classified as having two geologically distinct parts, the oceanic crust and the continental crust. The interior of the earth and the oceanic crust are continually being reworked and recycled by plate tectonics. The continental crust does not undergo subduction and therefore is more stable over geologic time. One way to study the continental lithosphere is through seismic tomography. Seismic tomography uses data from waves generated by earthquakes that travels throughout the continental lithosphere and are recorded by seismic stations. Seismologists use the ray paths of the waves and the travel times of the waves to create a 3-D model of the continental crust similar to how MRI machines create images of the interior of the human body. Complex geological features in the United States can be explored by these 3-D models of the subsurface. For my EAPSI Fellowship, I was privileged to work with Dr. Li Zhao, a leading computational and theoretical seismologist at Academia Sinica in Taiwan, who is working on application of sensitivity kernels. Sensitivity kernels are a new method that can be included in the calculation of 3-D models. Sensitivity kernels improve the resolution of the 3-D model and can give us more details about the structures inside the earth. Working with Dr. Zhao allowed me to become proficient in the application and computation of sensitivity kernels. It is a new method that I can use to investigate geologic structures in many regions. While in Taiwan, I calculated sensitivity kernels for the island of Taiwan. Now that I have learned the computational method, I will use sensitivity kernels to create a higher resolution image of the United States. The results that I obtained while in Taiwan were presented to the researchers at the Institute of Earth Sciences at Academia Sinica and are also the subject of my poster at the 2011 American Geophysical Union Fall Meeting. I will continue to calculate sensitivity kernels for North America to create a higher resolution model of the subsurface. My research in Taiwan also gave me insight into the cultural and scientific differences of the eastern part of the world, which is extremely important when building working relationships. The exposure to a different culture made me aware of the differences in infrastructure, research policies, and communication that need to be understood and bridged when working globally.