This grant provides partial support ($90,000 of a total budget of $526,000, or 17%) of the International Seismological Centre (ISC) at the University of Reading, United Kingdom. The ISC dataset is widely used by U.S. scientists and has made possible the first large-scale attempts at determining 3-D structure of the earth. It is an essential resource for the determination of world-wide seismicity which is a necessary component in earthquake hazard studies throughout the world. This grant is a component of the National Earthquake Hazard Reduction Program.