Finite-difference time-domain model for elastic waves in the ground

A 2D finite-difference model for elastic waves in the ground has been developed. The model uses the equation of motion and the stress-strain relation, form which a first order stress-velocity formulation is obtained. The resulting system of equations is discretized using centered finite- differences. A perfectly matched layer surrounds the discretized solution space and absorbs the outward traveling waves. The numerical model is validated by comparison to an analytical solution. The numerical model is then sued to study the interaction of elastic waves with buried land miens. Results are presented for a buried antipersonnel mine. It can be seen, that an air-chamber within the mine is excited to resonant oscillations, which are clearly visible on the surface above the mine. The simulation results agree fairly well with experimental observations. Differences are mainly due to the numerical model being 2D. Currently, the finite-difference model is being extended to 3D.