This grant is to provide partial support for a two-day workshop entitled "Frontiers of Broad Band Seismology" jointly sponsored by the University of California at Berkeley and the California Institute of Technology. It will be held on January 9-10, 1991, in Berkeley, California. Recent advances in the technology of broad-band seismic instrumentation have led to a revolution in the design and installation of seismic arrays in the western United States. Major advances in our knowledge of earthquakes and the interior of the earth are possible from this new capability. The workshop will facilitate data storage and formatting and ensure access to the massive amounts of information that will be generated. It will also provide a broad spectrum of both U.S. and international scientists an opportunity to develop and extend strategies for analysis in future research. This research is a component of the National Earthquake Hazard Reduction Program.