Reflection seismics

In reflection seismology we record seismic pulses that are reflected from boundaries which separate layers that have different acoustic impedances. Unlike in refraction surveying, information in the seismogram which comes after the first arrival is important. In general the processing is considerably different than in refraction surveying.

In reflection seismology, seismic records from many sets of shots and receivers are used to generate a Normal Incidence Reflection Seismogram which has reflections that correspond to a vertically traveling wave. The reflections occur at travel times that are determined by the velocity and the length of the travel path in each layer. The normal incidence reflection seismograms are acquired at regular distances along the surface and are composited into a seismic section. This generates an image of the substructure that can be used in an identical manner to a radar section.

In order to benefit from gathering several echoes from each reflecting point there are numerous operations that need to be applied to the data.

• Normal Incidence Reflection Seismogram
• Filtering of Seismic Data
• Turning data into a seismic profile
• Static Corrections
• Migration
• Vertical Resolution

Note

From Kearey, Philip and Micheal Brooks, ‘An Introduction to Geophysical Exploration’. 2nd ed. Blackwell Science: 1991.