This is known as absorption (or anelastic attenuation) and will eventually cause the total disappearance of the seismic wave.
[2] The earth preferentially attenuates higher frequencies, resulting in the loss of signal resolution as the seismic wave propagates.
[4] Therefore, if Q can be accurately measured then it can be used for both compensation for the loss of information in the data and for seismic attribute analysis.
[5] The geometry of a zero-offset vertical seismic profile (VSP) makes it an ideal survey to use for the calculation of Q using the spectral ratio method.
Stacked surface seismic reflection traces would offer similar signal-to-noise ratio over a much larger area but cannot be used with this method because every sample represents a different raypath and therefore will have experienced different attenuation effects.
Taking logarithms of both sides and rearranging: This equation shows that if the logarithm of the spectral ratio of the amplitudes before and after traversing the medium is plotted as a function of frequency, it should yield a linear relationship with an intercept measuring the elastic losses (R and G) and the gradient measuring the inelastic losses, which can be used to find Q.
Lg may be suddenly disappeared along a particular propagation path which is commonly seen at continental-oceanic transition zones.