  We study the recovery of piecewise analytic density and stiffness tensor of a
three-dimensional domain from the local dynamical Dirichlet-to-Neumann map. We
give global uniqueness results if the medium is transversely isotropic with
known axis of symmetry or orthorhombic with known symmetry planes on each
subdomain. We also obtain uniqueness of a fully anisotropic stiffness tensor,
assuming that it is piecewise constant and that the interfaces which separate
the subdomains have curved portions. The domain partition need not to be known.
Precisely, we show that a domain partition consisting of subanalytic sets is
simultaneously uniquely determined.
