Rapid shear wave velocity imaging with seismic landstreamers and surface wave inversion

Abstract

Surface wave data acquisition by landstreamer with flat baseplates produces nearly identical dispersion curves to those from planted geophones. Dependence on geophone frequency and good coupling is negligible and repeatability is fair. The primary application of landstreamers is to produce 2D shear wave velocity profiles through 1D inversion of a number of dispersion curves at high shot density, and numerical modelling shows that this workflow provides accurate subsurface images. However, in the vicinity of a shallow, soft-layer termination, its lateral extent can be overestimated by about 10% of the recording spread length. Shorter spreads show less wavefield scattering but more dependence on source-receiver geometry, and the response is dominated by the material under the nearer-offset channels.