9706056 Laske This research involves a new global and regional analysis of seismic anisotropy using surface wave data. The results of this study are expected to shed light on the nature of large-scale and medium-scale flow patterns in the oceanic mantle. The compatibility of the data with anisotropy models developed for the continental lithosphere using shear-wave splitting data will also be studied. It has been several years since the last large-scale study of anisotropy using surface waves and the potential datasets have expanded tremendously in the intervening time. The critical feature which distinguishes this study from previous studies is the use of particle motion information as well as phase to discriminate anisotropic effects from those of lateral heterogeneities. ***