Head waves in laterally heterogeneous media

Velocity Analysis for Laterally Heterogeneous Anisotropic Media

Oil, gas, and geothermal reservoirs, and overlying strata are often composed of anisotropic rocks. Proper treatment of anisotropy during the processing of seismic data not only helps to avoid distortions in reservoir imaging, but also provides estimates of the anisotropic coefficients, which carry valuable information about lithology and fracture networks. Accurate estimation of the velocity mo...

Seismic ray tracing and wavefront tracking in laterally heterogeneous media

One of the most common and challenging problems in seismology is the prediction of source-receiver paths taken by seismic energy in the presence of lateral variations in wavespeed. The solution to this problem is required in many applications that exploit the high frequency component of seismic records, such as body wave tomography, migration of reflection data and earthquake relocation. The pr...

Surface Waves in Laterally Inhomogeneous Regions

Scattering of elastic waves in heterogeneous media with local isotropy.

The scattering of elastic waves in heterogeneous media is discussed. Explicit expressions are derived for the attenuation of longitudinal and transverse elastic waves in terms of the statistics of the density and Lamé parameter fluctuations. The derivation is based upon diagrammatic methods with the problem posed in terms of the Dyson equation. The Dyson equation is solved for the mean field re...

Highly nonlinear solitary waves in heterogeneous periodic granular media

We use experiments, numerical simulations, and theoretical analysis to investigate the propagation of highly nonlinear solitary waves in periodic arrangements of dimer (two-mass) and trimer (threemass) cell structures in one-dimensional granular lattices. To vary the composition of the fundamental periodic units in the granular chains, we utilize beads of different materials (stainless steel, b...