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Volume 9 Number 2
  • E-ISSN: 1365-2478

Abstract

A

Laboratory measurements indicate that seismic absorbtion in sedimentary rocks lies in the range 0.1 to 1.0 decibel per wavelength. Field measurements on the amplitude attenuation of direct, reflected and refracted pulses give values consistent with this.

If the absorption is linear, dispersion must occur. If it occurs field measurements show that it must be less than 1% over the frequency range 20 c/s to 20 kc/s.

Seismic pulses broaden so slowly with distance that, if the absorbtion is linear it must be less than that measured in the laboratory by a factor of at least ten. This is inconsistent with the amplitude measurements and would mean that emplaced rocks are more perfectly elastic than steel.

Seismic absorbtion must therefore be non‐linear. It is assumed that, for large values of Q, the non‐linear equation of motion may be linearised (Knopoff and MacDonald, 1958) and Fourier synthesis used. If this is valid, then the attenuation per unit distance must be practically independent of frequency and dispersion must be negligible.

Whatever mechanism is acting it must produce an attenuation of roughly one decibel per 1000 feet and a pulse broadening of about 1–2% in the same distance.

It is extremely desirable to make more field and laboratory experiments to determine the physical mechanism by which absorbtion takes place.

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2006-04-27
2024-04-19

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References

  1. Biot, M. A., 1956, Theory of Propagation of Elastic Waves in a Fluid‐Saturated Porous Solid. I. Low Frequency Range, J. Ac. Soc. Am., 28, 2, 168–178.
    [Google Scholar]
  2. Birch, F. and Bancroft, D., 1938, Elasticity and Internal Friction in a Long Column of Granite, B.S.S.A., 28, 243–254.
    [Google Scholar]
  3. Bois, P., Chaveau, J., Grau, G. and Lavergne, M., 1960, Seismogrammes Synthetiques; Possibilités, Techniques de Réalisation et Limitations, Appendice 4, Geoph. Prospecting, 8 (2), 260–314.
    [Google Scholar]
  4. Born, W. T., 1941, The Attenuation Constant of Earth Materials, Geophysics, 6 (2), 132–148.
    [Google Scholar]
  5. Bruckshaw, J. and Mahanta, P., 1954, The Variations of Elastic Constants of Rocks with Frequency, Petroleum, 17, 14–18.
    [Google Scholar]
  6. Fortsch, O., 1956, Die Ursachen der Absorption Elastischer Wellen, Annali di Geofisica, 9, 4, 469–524.
    [Google Scholar]
  7. Gutenburg, G., 1958, Attenuation of Seismic Waves in the Earth's Mantle, B.S.S.A., 48, 269–282.
    [Google Scholar]
  8. Karus, E. V., 1958, The Absorption of Elastic Vibrations in Rocks during Stationary Excitation, Bull. Ac. Sc. USSR, Geophysics Series, (English Translation), 249–254.
  9. Kendall, J. H., 1941, The Range of Amplitudes in Seismic Reflection Records, Geophysics, 6 (2), 149–157.
    [Google Scholar]
  10. Knopoff, L., 1956, The Seismic Pulse in Materials Possessing Solid Friction, I: Plane Waves, B.S.S.A., 46, 3, 175–185.
    [Google Scholar]
  11. Knopoff, L. and MacDonald, G., 1958, Attenuation of Small Amplitude Stress Waves in Solids, Reviews of Modern Physics, 30 (4), 1178–1192.
    [Google Scholar]
  12. Kolsky, H., 1956, The Propagation of Stress Pulses in Viscoelastic Solids, Phil. Mag., ser. 8, 1, 8, 693–710.
    [Google Scholar]
  13. McDonal, F. J., Angona, F. A., Mills, R. L., Sengbush, R. L., Van Nostrand, R. G., and White, J. E., 1958, Attenuation of Shear and Compressional Waves in Pierre Shale, Geophysics, 23, (3), 421–439.
    [Google Scholar]
  14. O'Brien, P. N. S., 1960. The Use of Amplitude and Frequency in Exploration Seismology, Section I, Proc. 5th World Pet. Congress, 627–644.
  15. Peselnick, L. and Zietz, I., 1959, Internal Friction of Fine Grained Limestones at Ultrasonic Frequencies, Geophysics, 24, 2, 285–296.
    [Google Scholar]
  16. Press, F. and Ewing, M., 1954, An Investigation of Mantle Rayleigh Waves, B.S.S.A., 44, 127–149.
    [Google Scholar]
  17. Ricker, N., 1951, The Form and Laws of Propagation of Seismic Wavelets, Section I, Proc. 3rd World Pet. Congress, 514–536.
  18. Usher, M., 1961, Private Communication and forthcomingPh. D. Thesis at University of London (Imperial College).
  19. Jakowsky, J. J., 1950, „Exploration Geophysics”, Trija, Los Angeles, 2nd Edition. (a) page 683, equation 42. (b) page 687, equation 55.
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