Sensitivity kernels or partial derivatives of phase velocity (c) and group velocity (U) with respect to medium parameters are useful to interpret a given set of observed surface wave velocity data. In addition to phase velocities. group velocities are also being observed to find the radial anisotropy of the crust and mantle. However. https://parisnaturalfoodes.shop/product-category/vitd3-400-iu-liquld/