9316032 Jordan This research is to calculate properties of mantle flow that can be tested by means of global seismic data. 2-D and 3-D numerical experiments will be done to catalog the types of flow models consistent with the observed radial correlation function, as well as other diagnostics. Important parameters include the viscosity profile and the amount of internal heating. Seismic modeling will be directed at two topics. 1) Data sets for determining 3-D mantle structure will be improved by the development of multi-mode estimation techniques for extracting the parameters that describe free-oscillation multiplets split by aspherical heterogeneity. 2) The seismological inverse problem will be reformulated in terms of a two-point correlation function, a stochastic approach where the angular integrations are replaced by averages over products between pairs of data points. ***
