9405948 Masters This research is to continue an investigation of long-period body wave data in order to resolve aspherical elastic and anelastic structure in the mantle. The main areas of focus will be 1) the measurement and interpretation of global datasets of body-wave attenuation - special emphasis will be on constraint of lateral variations in Q structure which will complement other studies that use surface waves. An attempt will also be made to constrain the form of the absorption band in the earth; 2) the use of body-waveform modeling to handle triplication regions of the seismograms - the method employs a 3-D ray tracer which is also useful for looking at non- linear behavior of travel-time perturbations and 3) modelling of entire global datasets including various geodynamical prejudices. ***