The earthquake-induced change of scattering mechanism in the
swept area, U1, is characterized by a significant decrease of the doublebounce
scattering contribution due to vanished dihedral structures,
while the surface scattering component exhibits no apparent change.
The volume scattering power increases after tsunami damage as a result
of scattering from debris. Eigenvalue parameters (H, A, and α) all
decrease after the devastation. These changes indicate that the scattering
contribution from debris/mud-covered surfaces became dominant