Applications of Seismic Refraction Surveys
The seismic refraction method is commonly used to determine:
Depth to bedrock/rockhead
By understanding the seismic velocities of the overlying materials it is possible to produce an estimate of the depth to rockhead/bedrock. This is essential information for many engineering and environmental projects.
Water Table Mapping
A seismic refraction survey can help to map the position of a water table. The water table is typically a low-velocity layer and as such will be imaged as a high reflector on the seismic sections.
Geological Interpretations
A seismic refraction survey can provide detailed information on the shallow subsurface. This information can be used to support engineering designs or for environmental site characterisation.
Landfill Delineation
A seismic refraction survey can be used to delineate the boundaries of a landfill. A seismic survey will produce a velocity model of the subsurface.
The waste materials within the landfill will generally have a lower seismic velocity than the surrounding soils. As such, the landfill will appear as a low-velocity zone on the seismic sections.
Cavity and fracture detection
The seismic refraction method can be used to detect the presence of voids and fractures within the subsurface. These features will produce reflections on the seismic sections.
The amplitude and character of the reflections can provide information on the size, orientation, and depth of the voids/fractures.
Near-surface faulting
Faults can be imaged using seismic refraction data. The position of the fault will produce a reflection on the seismic sections. The amplitude and character of the reflection can provide information on the type of faulting present.