Seismic Techniques
Seismic Reflection Profiling
Outline
Seismic reflection profiling involves the measurement of the two-way travel time of seismic waves transmitted from surface and reflected back to the surface at the interfaces between contrasting geological layers. Reflection of the transmitted energy will only occur when there is a contrast in the acoustic impedance (product of the seismic velocity and density) between these layers. The strength of the contrast in the acoustic impedance of the two layers determines the amplitude of the reflected signal. The reflected signal is detected on surface using an array of high frequency geophones. As with seismic refraction, the seismic energy is provided by a 'shot' on surface. For shallow applications this will normally comprise a hammer and plate, weight drop or explosive charge.
