pure and applied geophysics

, Volume 128, Issue 1–2, pp 157–193 | Cite as

Numerical-analytical interfacing in two dimensions with applications to modeling NTS seismograms

  • Richard J. Stead
  • Donald V. Helmberger
Article

Abstract

A new method for interfacing numerical and integral techniques allows greater flexibility in seismic modeling. Specifically, numerical calculations in laterally varying structure are interfaced with analytic methods that enable propagation to great distances. Such modeling is important for studying situations containing localized complex regions not easily handled by analytic means. The calculations involved are entirely two-dimensional, but the use of an appropriate source in combination with a filter applied to the resulting seismograms produces synthetic seismograms which are point-source responses in three dimensions. The integral technique is called two-dimensional Kirchhoff because its form is similar to the classical three-dimensional Kirchhoff. Data from Yucca Flat at the Nevada Test Site are modeled as a demonstration of the usefulness of the new method. In this application, both local and teleseismic records are modeled simultaneously from the same model with the same finite-difference run. This application indicates the importance of locally scattered Rayleigh waves in the production of teleseismic body-wave complexity and coda.

Key words

Scattering finite difference Kirchhoff integration NTS 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Baker, B. B. andCopson, E. T.,The Mathematical Theory of Huygens' Principle (Oxford University Press, London 1950) pp. 36–53.Google Scholar
  2. Eckren, E. B. (1968),Geologic setting of Nevada Test Site and Nellis Air Force Range, InNevada Test Site, GSA Memoir 110, (ed. Eckel, E. B.) (GSA, Boulder, CO) pp. 21–33.Google Scholar
  3. Frazer, L. N. andSen, M. K. (1985),Kirchhoff-Helmholtz reflection seismograms in a laterally inhomogeneous multi-layered elastic medium—I. Theory. Geophy. J. Roy. Astron. Soc.80, 121–147.Google Scholar
  4. Hart, R. S. Hadley, D. M. Mellman, G. R., andButler, R. (1979),Seismic amplitude waveform research, Final Technical Report SGI-R-79-012 (Sierra Geophysics).Google Scholar
  5. Hartzell, S. andHeaton, T. (1983),Inversion of strong ground motion and teleseismic waveform data for the fault rupture history of the 1979 Imperial Valley, California earthquake, Bull. Seism. Soc. Am.73, 1553–1583.Google Scholar
  6. Hays, W. W. andMurphy, T. R. (1970),The effect of Yucca Fault on seismic wave propagation, Report NVO-1163-TM-19 (Environmental Research Corporation, Las Vegas).Google Scholar
  7. Helmberger, D. V. (1983),Theory and application of synthetic seismograms, InEarthquakes: Observation, Theory and Interpretation, Proc. Int. Sch. Phys. “Enrico Fermi,” Course LXXXV, (eds., Kanamori, H. and Boschi, E.) (North-Holland Publ., Amsterdam) pp. 174–221.Google Scholar
  8. Helmberger, D. V. andHadley, D. M. (1981),Seismic source functions and attenuation from local and teleseismic observations of the NTS events JORUM and HANDLEY, Bull. Seism. Soc. Am.71, 51–67.Google Scholar
  9. Hilterman, F. J. (1975),Amplitudes of seismic waves—a quick look, Geophysics40, 745–762.Google Scholar
  10. Houser, F. N. (1968),Application of geology to underground nuclear testing, Nevada Test Site, InNevada Test Site, GSA Memoir 110, (ed. Eckel, E. B.) (GSA, Boulder, CO) pp. 11–19.Google Scholar
  11. Hudson, J. A. (1963),SH waves in a wedge-shaped medium, Geophys. J. Roy. Astron. Soc.7, 517–546.Google Scholar
  12. Keho, T. H. andWu, R. S. (1987),Elastic Kirchhoff migration for vertical seismic profiles, Society of Exploration Geophysics, Extended abstract with biographies, pp. 774–776.Google Scholar
  13. Lay, T. (1987a),Analysis of near-source contributions to early P-wave coda for underground explosions: 2. Frequency dependence, Bull. Seism. Soc. Am.77, 1252–1273.Google Scholar
  14. Lay, T. (1987b),Analysis of near-source contributions to early P-wave coda for underground explosions: 3. Inversion for isotropic scatterers, Bull. Seism. Soc. Am.77, 1767–1783.Google Scholar
  15. Lay, T., Wallace, T. C., andHelmberger, D. V. (1984),Effect of tectonic release on short period P waves from NTS explosions, Bull. Seism. Soc. Am.74, 819–842.Google Scholar
  16. Lynnes, C. S. andLay, T. (1988),Observations of teleseismic P-wave coda for underground explosions, PAGEOPH, this issue.Google Scholar
  17. Mow, C. C. andPao, Y. H. (1971),The Diffraction of Elastic Waves and Dynamic Stress Concentrations (Report R-482-PR for United States Air Force Project Rand, Santa Monica, CA) pp. 140–171.Google Scholar
  18. Scott, P. andHelmberger, D. (1983),Applications of the Kirchhoff-Helmholtz integral to problems in seismology, Geophys. J. Roy. Astron. Soc.72, 237–254.Google Scholar
  19. Taylor, R. T. (1983),Three-dimensional crust and upper mantle structure at the Nevada Test Site, J. Geophys. Res.88, 2220–2232.Google Scholar
  20. Vidale, J. E. (1986),Application of two-dimensional finite-differencing methods to simulation of earthquakes, earth structure, and seismic hazard (Thesis, Calif. Institute of Tech., Pasadena).Google Scholar
  21. Vidale, J. E. andHelmberger, D. V. (1987a),Path effects in strong motion seismology, chapter 6 InMethods of Computational Physics (ed. Bolt, B.) (Academic Press, New York) pp. 267–319.Google Scholar
  22. Vidale, J. E. andHelmberger, D. V. (1987b),Elastic finite-difference modeling of the 1971 San Fernando, Ca. earthquake, Bull. Seism. Soc. Am.78, 122–141.Google Scholar
  23. Vidale, J. E., Helmberger, D. V., andClayton, R. W. (1985),Finite-difference seismograms for SH waves, Bull. Seism. Soc. Am.75, 1765–1782.Google Scholar

Copyright information

© Birkhäuser Verlag 1988

Authors and Affiliations

  • Richard J. Stead
    • 1
  • Donald V. Helmberger
    • 1
  1. 1.Seismological LaboratoryCalifornia Institute of TechnologyPasadenaUSA

Personalised recommendations