A New Linearized AVAF Expression in Anelastic Media

The geophysics literature contains numerous reports of frequency-dependent seismic data anomalies associated with low Q (Quality factor) targets. Q effect can be examined in big scale and small scale. In the big scale, low Q value can influence the amplitude and the arrival time of the wave. In the small scale, the reflection coefficient at the interface would not only vary with angle but also frequency when it exists Q difference between upper layer and lower layer. That’s why we need to study AVAF (Amplitude Versus Angle and Frequency). We use Taylor expansion to linearize the phase velocity reflection and then obtain a very concise formula to express the AVAF relationship in anelastic media. This new linearized AVAF expression has separated the velocity difference reflection and Q difference reflection which would give us some guidance to AVAF inversion. The equation is proved accurate enough even the Q value is approaching 5.