9603327 Tajima This award supports a one year collaborative research project between Professor Fumiko Tajima of the University of Texas in Austin, Professor Craig Bina of Northwestern University and Dr. Yoshio Fukao of the Earthquake Research Institute at the University of Tokyo in Japan. This project involves a seismological study of the upper mantle transition zone associated with the Northwestern Pacific subduction zones. The major goal of this project is to improve the 3-D images produced by tomographic inversion. The project brings together the efforts of two major laboratories that have constituted different parts of the process: the Americans will produce thermal and bulk compositional models for the mantle and subduction zone and the Japanese will correct for residuals and modify the 3-D travel time inversion code to include travel time data for later arrivals. The seismic structure of the upper mantle transition zone, from 400-700 km depth is of fundamental importance for understanding the mode of convection within the Earth's mantle. Improving the 3-D whole mantle tomographic models will provide for better understanding of this structure. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. ***
