Ray-reflectivity method for the P-S_V case: Basic numerical results

P. F. Daley

In an earlier report the theory for the implementation of the ray-reflectivity method has been presented. The use of this method for realistic geological situations might be counterproductive, as a demonstration of many of the basic developments could be lost. Possibly the most interesting of these is what has been termed the tuning of the thin layer using different variations of input parameters. As a result only a simple model consisting of a layer over a half space is considered. These two media are separated by a thin transition layer in which the elastic parameters can be chosen for it to be either a low or high velocity channel. The main objectives of this report are to present the reflected PP and PS reflectivities from the top of the thin layered zone. The reflectivities are dependent on, apart from the elastic parameters of the layer, thin layer and half space, angle of the incident wave type, thickness of the thin layer and frequency. The most efficient manner of doing this is with 3D plots; reflectivity amplitude versus incident angle and frequency being one possibility. Additionally, some simple reflection synthetic seismograms will be shown to indicate the change in the seismic traces as a result of changes in, say, the predominant frequency of the source wavelet.