Blurring the line between intrinsic and scattering attenuation by means of the Shannon entropy

Kristopher A. H. Innanen

We compute a version of the Shannon entropy S of snapshots of a seismic wave field as it propagates. S is argued to be a measure of the degree of either multiple scattering, or attenuation, or both, experienced by the wave, evolving similarly regardless of which process dominates in a given example. Invoking it, therefore, forces us to reject the distinction between intrinsic and extrinsic attenuation, and allows us to place thin-bed reverberations above and below the resolving power of the experiment on an equal footing should we decide to do so. S is easily computable, as is shown with both synthetic (“wave in a box”) examples and a field VSP example. It relies on stable estimates of the histograms of wave amplitude values, and the best way of doing this is still under investigation.