Elasticity profile of an unconsolidated granular medium inferred from guided waves: Toward acoustic monitoring of analogue models

The monitoring of materials elastic parameters during geological analogue experiments would highly improve the interpretation of involved processes. It would more particularly help the implementation of joint analytical or numerical analyses. We propose laser-Doppler vibrometry as a probing tool for the systematic characterisation of analogue models. We therefore develop an experimental set-up to record small-scale seismic lines at the surface of an unconsolidated granular medium in laboratory conditions. Pressure-wave first arrival times and surface-wave dispersion are then inverted for a one-dimensional Pressure- and Shear-wave velocity structure. Inferred profiles appear to match previously thoroughly estimated properties of the probed medium, thus validating our approach.