The variation of reflection and transmission coefficients with incident angle and thus offset is commonly known as offset-dependent reflectivity. The Zoeppritz equations Zoeppritz (1919) describe the reflection and transmission coefficients as a function of incident angle and elastic media properties (density, P-wave velocity, and S-wave velocity). They apply to a reflection of plane-waves between two half-spaces, and do not include wavelet interferences due to layering. Furthermore, amplitudes are a measure of the reflection coefficient only when effects that cause amplitude distortions have been removed. Thus, preprocessing to remove transmission loss, source and receiver effects, spherical divergence, multiples, and so on, is essential to the successful recovery of the reflection coefficients.
The variation of the P-wave reflection coefficient with offset and angle, which is the basis of AVO analysis, can be used as a direct hydrocarbon indicator Ostrander (1984). Therefore, it should help in delineating the possible causes and characteristics of the BSR in the data from the Blake Outer Ridge.