Quasi Two-dimensional Transfer of Elastic Waves
Abstract
A theory for multiple scattering of elastic waves is presented in a random medium bounded by two ideal free surfaces, whose horizontal size is infinite and whose transverse size is smaller than the mean free path of the waves. This geometry is relevant for seismic wave propagation in the Earth crust. We derive a time-dependent, quasi-2D radiative transfer equation, that describes the coupling of the eigenmodes of the layer (surface Rayleigh waves, SH waves, and Lamb waves). Expressions are found that relate the small-scale fluctuations to the life time of the modes and to their coupling rates. We discuss a diffusion approximation that simplifies the mathematics of this model significantly, and which should apply at large lapse times. Finally, coherent backscattering is studied within the quasi-2D radiative transfer equation for different source and detection configurations.
Cite
@article{arxiv.cond-mat/0104049,
title = {Quasi Two-dimensional Transfer of Elastic Waves},
author = {Nicolas P. Tregoures and Bart A. van Tiggelen},
journal= {arXiv preprint arXiv:cond-mat/0104049},
year = {2009}
}
Comments
REVTeX, 36 pages with 10 figures. Submitted to Phys. Rev. E