The technique of refraction diving wave, or curved ray path tomography is appropriate for deriving the velocity gradient field under complex geological conditions. The seismic velocity field is a direct representation of the rock rigidity distribution in the subsurface. The velocity gradient field facilitates the identification of lithological layers and also the detection of decompaction zones.
Depending on the ray’s angle of incidence with the interface, part of the acoustic energy travels as a totally refracted wave along the interface boundary and continuously emits energy back to the surface. The surface of a hard formation with a high seismic propagation velocity so to speak exerts an attractive force on the trajectories of raypaths, which as rule represents the fastest route between two points.
- mapping of decompacted zones
- determination of rippability
- mapping of permeability of gravels
- 2D and 3D mapping of the bedrock surface
- depth of investigation: until 150 m