Accession Number : ADP204464

Title :   A Spectral Scheme for Viscoelastic Seismic Modeling,

Corporate Author : WYOMING UNIV LARAMIE DEPT OF MATHEMATICS

Personal Author(s) : Schatzman, James C. ; Meng, Zhaobo

PDF Url : ADP204464

Report Date : 14 AUG 1995

Pagination or Media Count : 8

Abstract : The pseudospectral method is especially valuable for seismic modeling because of its high accuracy compared to other numerical techniques. The method can be regarded as a limit of finite difference of increasing orders, and a process of trigonometric interpolation, thus it exhibits high accuracy. Stability of the method is also favorable. Fourier polynomials are especially efficient but have the disadvantage of forcing periodicity, and Chebyshev polynomials are somewhat less efficient but are more flexible in application of boundary conditions. We have used a Fourier pseudospectral method in the horizontal direction and Chebychev polynomials in the vertical direction. Curved grids conforming to the surface topography and major interfaces are made possible by coordinate transformations. A full viscoelastic formulation permits convenient implementation of attenuating layers to reduce wrap-around in the horizontal direction. The result is an efficient method for 2- and 3-D linear viscoelastic wave propagation.

Descriptors :   *VISCOELASTICITY, *SEISMIC DETECTION, *SEISMIC WAVES, *ARMS CONTROL, *NUCLEAR EXPLOSION DETECTION, STRESS STRAIN RELATIONS, SYMPOSIA, MONITORING, FINITE ELEMENT ANALYSIS, UNDERGROUND EXPLOSIONS, TOPOGRAPHY, NUCLEAR EXPLOSION TESTING, WAVE PROPAGATION, BOUNDARY VALUE PROBLEMS, SEISMIC DISCRIMINATION, TREATIES, FOURIER ANALYSIS, TRAVEL TIME, CHEBYSHEV POLYNOMIALS.

Subject Categories : Government and Political Science
      Seismology
      Seismic Detection and Detectors
      Nuclear Weapons

Distribution Statement : APPROVED FOR PUBLIC RELEASE