Conversion and reflection of Rayleigh waves with the seismic metawedge

By combining concepts from elasticity, photonics and metamaterials, we present a seismic metasurface capable to convert or reflect seismic Rayleigh waves propagating in a sedimentary ground. The metasurface is obtained with an array of trees, with their height gradually decreasing to form a wedge-like profile, “the metawedge”. Local resonance phenomena between trees and ground, combined with the spatially varying profile of the wedge give rise to a twofold behavior depending on the incidence direction of the wavefront: (1) Rayleigh to shear wave conversion or (2) Rayleigh wave reflection.