We used a numerical model with a non-uniform rectangular mesh with 101x41 grid nodes.  Resolution is best in the shallow mantle near the spreading axis.  Symmetric spreading velocities are applied to the top, and a uniform horizontal velocity along the bottom to account for ridge migration (fixed-ridge reference frame).  Pressure differences are applied at the edges to examine the effects of pressure-driven asthenospheric flow near a spreading center.  Variables calculated in the models are: temperature, viscosity, velocity, melt prodution, and mantle depletion from melting.