Expected value and point-wise variance of the density field’s prior and posterior distributions when inverting for the sinkers’ viscosity. The first row shows the prior (a) mean and (b) point-wise variance, the other rows show the posterior mean and point-wise variance for different data types: (c) and (d) only horizontal velocities (V), (e) and (f) only normal traction (T), (g) and (h) both horizontal velocities and normal traction (V+T).