HR: 1330h
AN: S22B-0460    [PDF]
TI: Factors affecting the evaluation of scattering attenuation
AU: * Hong, T
EM: tkhong@es.ucsc.edu
AF: University of California at Santa Cruz, Earth Sciences Department 1156 High Street, Santa Cruz, CA 95064 United States
AU: Kennett, B L
EM: brian@rses.anu.edu.au
AF: The Australian National University, Research School of Earth Sciences, Canberra, ACT 0200 Australia
AU: Wu, R
EM: wrs@es.ucsc.edu
AF: University of California at Santa Cruz, Earth Sciences Department 1156 High Street, Santa Cruz, CA 95064 United States
AB: 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.
DE: 7203 Body wave propagation
DE: 7260 Theory and modeling
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2003 Fall Meeting