1.) Figure 1 roughly describes variations of Q-values with rock types. Use this figure to provide an explanation of the high attenuation of seismic waves generally observed in the weathering zone (near-surface zone).
2.) If the measurement a sand-shale sequences shows 20% P-wave anisotropy and 30% S-wave anisotropy, estimate the ratios C33/C11 and C44/C66.
Calculate VP, VS, and density ρ of a water-saturated Berea sandstone and of a water-saturated teapot sandstone:
where SS indicates sandstone.
Here is the stiffness tensor of a Pierre shale formation (near Limon, Colorado):
Cijkl = (C11 - 2 C66)δijδkl + C66δikδ jl + δ il δ jk)
+ (C11 + C33 - 2 C13 - 4 C44) δ i3δ j3 δk3 δ l3
+ (C13 - C11 + 2 C66) (δ…
Questions Derive the equations for the traveltime curves for the converted waves PSPS, PPSS, and PPSS (see Figure 3-51).
(i) Find the expressions for traveltimes of multiply reflected waves for the source and the receiver on the top surface (see Figure 3-52).
(ii) What happens when the dip angle is integral fraction of π?
(iii) When it is an irrational fraction of π?