Factors affecting the evaluation of scattering attenuation
Tae-Kyung Hong,
B.L.N. Kennett
and
Ru-Shan Wu
(2003)
AGU Fall Meeting, San Francisco, Dec. 8-12, 2003
The scattering of waves is a near ubiquitous phenomenon in the earth
and has been widely studied in seismology. Scattering attenuation can
be calculated by a formulation based on an approximation allowing for
both multiple forward-scattering and a single backscattering process.
In this approximation possible interaction between scattering in the
forward and backward directions is neglected.
In this study we examine the
effects of multiple scattering and propagation distance on the
evaluation of scattering attenuation through numerical experiments on
highly heterogeneous models. A change in propagation distance results
in the variation of the radius of the Fresnel zone, which controls the
interference volume of scattered waves. We find that primary waves
display a characteristic attenuation pattern depending on both the
frequency content of the incident waves and the change in propagation
distance. On the other hand, the coda energy is determined to be
nearly constant for changes in the random model and perturbation
level.