Hybrid seismic surveying

The method of hybrid seismic surveying is a combination of high resolution reflection seismic profiling with the technique of refraction seismic diving wave tomography, the two most common surface geophysical surveying disciplines in civil engineering.

Refraction seismic velocity field derived by diving wave tomography
Refraction seismic velocity field

Uninterpreted reflection seismic depth section
Reflection seismic depth section

Interpreted hybrid seismic section
Interpreted hybrid seismic section

Reflection seismic profiling as well as refraction diving wave tomography, when applied as the sole prospection methods, have their undisputed merits in their performance, but unfortunately also some shortcomings, depending on the objectives of each individual survey. Therefore, it is desirable to combine their data acquisition and interpretation procedures.

Thanks to the recent technical advances implemented in modern seismic recording instrumentation, the data acquisition for both methods can now be combined into one single operation, which results in a substantial reduction of the costs for field work. This allows tapping the full potential of the information contained in the data by an appropriate joint data processing procedure.

Although the results of the reflection seismic data processing and the refraction tomography evaluation are based on the same data set, they are completely independent from each other, which enhances the reliabililty of a joint interpretation. The latter is further assisted by a suitable presentation of two results whereby the drawbacks of one method are compensated by benefits of the other.

For a more detailed description of the hybrid seismic method read our publication Hybrid seismic surveying for detailed characterisation of the shallow and intermediate depths subsurface.