
Elastic wave propagation in model sediments – II
Author(s) -
Walton K.
Publication year - 1977
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1977.tb04184.x
Subject(s) - wave propagation , dispersion (optics) , mechanics , wave shoaling , attenuation , homogeneous , longitudinal wave , spheres , surface wave , elastic modulus , p wave , physics , geology , mechanical wave , optics , thermodynamics , astronomy , medicine , cardiology , atrial fibrillation
Summary. A fluid‐saturated cubic packing of like elastic spheres is taken to be in equilibrium under the effect of gravity and the effects of a superimposed low‐frequency elastic wave are considered. In the first place, expressions for the wave velocity, dispersion and attenuation are derived for the dry packing. This dynamic theory leads to the result that, for very low frequencies, the wave velocity is proportional to the third root of the depth and not the sixth root as is obtained by using the effective elastostatic modulus of the packing. For the fluid‐saturated packing, two waves, termed respectively the ‘solid wave’ and the ‘fluid wave’, are found to propagate. The ‘solid wave’ has the characteristics of a wave propagating within a dry packing whose parameters differ in a specified way from those of the original packing, whereas the ‘fluid wave’ has those of a wave within a homogeneous fluid with similarly modified parameters.