Analysis of Regional Phases Using Three-Component Data

Abstract : The objective of this project was to conduct basic research on the propagation of seismic energy at regional (100 to 1000 km) distances for purposes of monitoring underground nuclear explosions. The problems studied were scattering of seismic body waves by rough interfaces, the effect of anisotropic media on the seismic radiation from sources embedded in them, and the attenuation of crustal phases. This Final Report consists of preprints of four papers on these subjects. The first concerns scattering of body waves by rough interfaces. A plane wave (P or S) incident on a rough interface is considered. If the interface were plane the solution would be given by the classical reflection and transmission coefficients from which scattered field under the approximations that the interface height perturbation is much smaller than a wavelength and the interface slope perturbations are much less than unity. The solution may be expressed as three-dimensional scattering kernals that allow reconstruction of scattered reflected and transmitted fields. (eg)