Complex phase distribution and seismic velocity structure of the transition zone: Convection model predictions for a magnesium-endmember olivine-pyroxene mantle

► We have investigated complex spatial distribution of seismic shear wavespeed in the transition zone of the Earth's mantle by mantle convection modelling based on selfconsistent mineral physics, for a magnesium endmember olivine-pyroxene mineralogy. ► We find that heterogeneous structures are generated with predominant scale size of 50 km, near cold downwellings representing subducting lithosphere. These structures are well resolved in our mantle convection model with nodal point spacing of about 6 km in the transition zone. ► Synthetic reflectivity traces derived from radial profiles of the seismic wavespeed in our convection results indicate that the typical structures can be resolved by seismic reflectivity imaging upto about 20 s signal period.