Spreading of acoustic pulses due to laminated microstructure

                                   by

                               Knut Solna

               JTB 320, 3:20pm  Monday, 24 November, 1997


                                Abstract

We consider acoustic pulse propagation in inhomogeneous media over
relatively long propagation distances. Our main objective is to
characterize the spreading of the travelling pulse due to microscale
variations in the medium parameters. The pulse is generated by a point
source and the medium is modeled by a smooth three dimensional
background that is modulated by stratified random fluctuations. We refer
to such media as locally layered.

We show that, when the pulse is observed relative to its random arrival
time, it stabilizes to the pulse shape determined by the slowly varying
background convoluted with a Gaussian. The width of the Gaussian and the
random travel time are determined by the medium parameters along the ray
connecting the source and the point of observation.

A second objective is to establish a realistic model for fine scale
heterogeneities from measurements in a specific lithology.


Request for preprints and reprints to solna@math.utah.edu.
This information can be found at http://www.math.utah.edu/research/