Regional Phase Propagation in Three Dimensionally Heterogeneous Media

Abstract

The interaction of regional seismic phases with complex structure can lead to a significant modification of the seismic wavefield with the result of masking the characteristics of the source. A combination of theoretical, computational and observational studies have been directed to elucidating the effect of heterogeneity on regional phases. A new method has been developed for calculating the propagation of guided waves through a medium described by stochastic heterogeneity. This approach allows the estimation of the scattering contribution to the attenuation of Lg and Sn phases which can approach 30 percent for realistic heterogeneity structures. A ray based treatment has been devised to describe the way in which the Lg phase is affected by changes in the shape of the crustal waveguide due to topography at the surface and the Mohorovicic discontinuity. (JHD)

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Document Details

Document Type
Technical Report
Publication Date
Apr 11, 1990
Accession Number
ADA223279

Entities

People

  • Brian L. Kennett

Organizations

  • Australian National University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Department Of Defense
  • Differential Equations
  • Earth Models
  • Earth Sciences
  • Geography
  • Geophysics
  • North America
  • Phase Velocity
  • Planetary Sciences
  • Seismology
  • Three Dimensional
  • Topography
  • Two Dimensional
  • United States
  • Wave Propagation
  • Waveguides

Fields of Study

  • Physics

Readers

  • Atmospheric Science/Meteorology
  • Theoretical Analysis.
  • Wave Propagation and Nonlinear Chaotic Dynamics.