9713299 Synolakis This action is to support the organization of a two-day workshop on seafloor ground deformation models. The workshop is to be held at the University of Southern California Marine Science Station on Catalina Island, 14-15 May 1997. The objective of the workshop is to examine the state-of-the- art of interfacial seismology and tsunami hydrodynamics; in particular, whether the initial conditions for the seafloor displacement inferred from seismic records are adequate for tsunami runup computations. Whereas there have been significant advances in hydrodynamics, these advances have concentrated almost entirely and appropriately on the refinement of the inundation computations. At the same time, despite anecdotal advances in seismology, these advances have not been absorbed by the hydrodynamics community. As a result, hydrodynamics modelers use very elaborate shoreline computations, while using -- at the very best -- initial conditions based on a dislocation theory which has been in existence for twenty years or more. Also, the usefulness of the hydrodynamics computations to better define the ground deformation needs to be better understood by the seismology community. Since inundation maps for the west coast of the US are currently being prepared using tsunami runup computations, the question of the determination of the ground deformation is critically important. It is the objective of the workshop to provide a forum for seismologists and hydrodynamicists to discuss advances, and to identify short-term research needs to better use the respective results. In each of the one-day discussions, the objective is to identify critical issues, to attempt to answer all the criteria questions which lie within the present state-of-knowledge, and to discover areas requiring more extensive study. At the conclusion of the workshop, it is expected that the tsunami research community will be in a better position to focus -- in a continuing way -- on the r emaining questions whose answers are needed to quantify better the input provided by ocean-bottom pressure transducer recordings to tsunami warning systems.