Interferometry derived S-wave velocity model with geological constrains for induced seismicity monitoring

Both P-wave and S-wave velocity models are needed for location of induced seismicity from sparse monitoring arrays. While P-waves are usually known (reflection surveys or sonic logs), S-wave models need additional constrains. We use seismic noise interferometry to obtain Rayleigh surface waves between receivers of the sparse array. We invert the Rayleigh wave dispersion curves for the S-wave velocity structure beneath the array with additional constrains on layer boundaries derived from the P-wave model. An application on a sparse array in urban environment in The Hague, The Netherlands, reveals very low S-wave velocities in the near surface layers and S-wave increase with depth. Both of these observations are consistent with unconsolidated sediments and S-wave velocities observed in other parts of the Netherlands (Groningen).