Waves in an elastic medium generated by a point source moving in an overlying fluid medium

1973 ◽  
Vol 110 (1) ◽  
pp. 1932-1938 ◽  
Author(s):  
A. Ungar ◽  
Z. Alterman
Keyword(s):  
Point Source ◽  
Elastic Medium ◽  
Fluid Medium

Attenuation of seismograms obtained by the Cagniard‐Pekeris method

Geophysics ◽  
1983 ◽  
Vol 48 (9) ◽  
pp. 1204-1211 ◽  
Author(s):  
P. G. Kelamis ◽  
E. R. Kanasewich ◽  
F. Abramovici
Keyword(s):  
Reflection Coefficient ◽  
Point Source ◽  
Frequency Domain ◽  
Elastic Medium ◽  
Half Space ◽  
Ad Hoc ◽  
Synthetic Seismograms ◽  
Weathered Layer ◽  
Attenuation And Dispersion

Attenuation and dispersion are included in synthetic seismograms obtained by a Cagniard‐Pekeris formulation for the problem of a point source in a layer over a half‐space. The solution is decompose into generalized rays, and the effects of attenuation and dispersion are incorporated in an ad hoc manner in the frequency domain. The effects of the viscoelastic interfaces are taken into account by corrections to the reflection coefficient for an elastic medium. The results are illustrated with synthetics for a model simulating a weathered layer over a halt‐space. Both the SH and P‐SV cases are treated.

Azimuthal asymmetry of a point source in a cylindrical low velocity medium

1962 ◽  
Vol 52 (1) ◽  
pp. 139-144
Author(s):  
W. C. Meecham ◽  
John DeNoyer
Keyword(s):  
Point Source ◽  
Velocity Ratio ◽  
Density Ratio ◽  
Azimuthal Asymmetry ◽  
Low Density ◽  
Low Velocity ◽  
Frequency Dependent ◽  
Fluid Medium

Abstract The geometry of the medium in the vicinity of an otherwise symmetrical source is shown to produce a frequency dependent variation of amplitude with azimuth. The model considered is a cylindrical low velocity and low density fluid medium that is contained in a full space of a higher velocity and density fluid material. A simple harmonic point source is located on the axis of the cylinder. Amplitudes in the higher velocity medium at large distances from the source are found to be functions of the velocity ratio and the density ratio of the two media, the radius of the cylinder, the wavelength, and the angle between the axis of the cylinder and a line connecting the point of observation with the source.

A Student’s Guide to Teleseismic Body Wave Amplitudes

1992 ◽  
Vol 63 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Emile A. Okal
Keyword(s):  
Point Source ◽  
Elastic Medium ◽  
Elastic Waves ◽  
Body Wave ◽  
Seismic Sources ◽  
Geometrical Spreading ◽  
Seismic Amplitude ◽  
Anelastic Attenuation ◽  
Algebraic Expressions ◽  
Double Couple

Abstract We discuss the nature of the various factors contributing to the amplitude of a teleseismic body wave in the context of a geometrical ray solution, specifically: the radiation of elastic waves into an elastic medium by a point source; the radiation patterns resulting from the orientation of the double-couple in space; the effect of propagation through a radially heterogeneous Earth, known as geometrical spreading; the effect of anelastic attenuation; the contribution of depth phases to the seismogram; and finally the influence of distance on the receiver response function. For each of these parameters, we emphasize the physical arguments underlying the exact algebraic expressions of the various factors contributing to the seismic amplitude. Finally, we discuss the extension of the geometrical ray solution to deep seismic sources.

Elastic waves in anisotropic media

1959 ◽  
Vol 253 (1275) ◽  
pp. 563-580 ◽  
Keyword(s):  
Point Source ◽  
Elastic Medium ◽  
Elastic Waves ◽  
Isotropic Medium ◽  
Transversely Isotropic ◽  
Anisotropic Media ◽  
Transversely Isotropic Medium ◽  
Anisotropic Elastic Medium ◽  
Anisotropic Elastic ◽  
Fourier Integrals

The displacements due to a radiating point source in an infinite anisotropic elastic medium are found in terms of Fourier integrals. The integrals are evaluated asymptotically, yielding explicit expressions for displacements at points far from the source. The relative amplitudes of waves from a point source are thus determined, and it is found that although in general the decay of wave amplitudes is proportional to the distance from the source, it is possible that in certain directions the decay is less than this. The method used in this paper is also shown to be an alternative way of deriving known results concerning the geometry of the propagation of disturbances. As an example, the radiation in a transversely isotropic medium from an isolated force varying harmonically with time is discussed.

Surface motion due to a point source in a semi-infinite elastic medium*

1954 ◽  
Vol 44 (4) ◽  
pp. 571-596
Author(s):  
Edmund Pinney
Keyword(s):  
Point Source ◽  
Elastic Medium ◽  
Elastic Solid ◽  
Point Sources ◽  
P Wave ◽  
Tabular Form ◽  
Internal Point ◽  
S Wave ◽  
Surface Motion

Abstract The theory of the motion of the surface of a semi-infinite elastic solid due to an impulsive internal point source is developed, both for P-wave and S-wave point sources. The resulting motions have been computed numerically for the case λ = μ and are presented both in tabular form and graphically.

Field of a point source in a semi-infinite elastic medium

2012 ◽  
Vol 22 (3) ◽  
pp. 423-434 ◽  
Author(s):  
Alexey Val'kov ◽  
Vladimir Kuzmin ◽  
Vadim Romanov ◽  
Margarita Nikitina ◽  
Sergey Kozhevnikov ◽  
...  
Keyword(s):  
Point Source ◽  
Elastic Medium
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