  We investigate the diffraction of singularities of solutions to the linear
elastic equation on manifolds with edge singularities. Such manifolds are
modeled on the product of a smooth manifold and a cone over a compact fiber.
For the fundamental solution, the initial pole generates a pressure wave
(p-wave), and a secondary, slower shear wave (s wave). If the initial pole is
appropriately situated near the edge, we show that when a p-wave strikes the
edge, the diffracted p-waves and s-waves (i.e. loosely speaking, do not
correspond to limits of p-rays which just miss the edge) are weaker in a
Sobolev sense than the incident p-wave. We also show an analogous result for an
s-wave that hits the edge, and provide results for more general situations.
