Relationship between ULVZ topography and mantle convection

The topography of Ultralow-Velocity Zones (ULVZ), located on the mantle side of the core-mantle boundary, varies between 5 and 40km. This variation in topography is influenced by multiple factors, such as density contrast between the ULVZ and mantle and micro-scale grain interaction (capillary tension) within the layer. Convection in the overlying mantle exerts an additional influence on the layer topography. In this study, we explore the distribution of melt within the layer, governed by mantle convection and capillary tension in opposition to the buoyancy force. A steady state equation reflecting the conservation of mass and momentum describes the topography as a result of a balance of forces. We used a 4th order Runge-Kutta solver to determine a numerical solution for melt distribution within the ULVZ layer. In examining the numerical solution, variation in the convective velocity of mantle circulation affects the topography of the ULVZ.