APPENDIX

$$\hbox{\rm C}_{11} {\hbox{\rm C}}_{13} \hbox{\rm C}_{33} \hbox{\rm C}_{44} \rho$$ Layer

1 0.48 0.32 0.48 0.15 0.75

2 0.50 0.39 0.50 0.10 0.70

3 0.68 0.31 0.68 0.36 0.90

4 0.88 0.36 0.88 0.51 0.80

5 1.12 0.72 1.12 0.40 1.25

6 1.27 1.03 1.27 0.24 1.00

7 1.33 0.66 1.33 0.66 1.10

8 1.43 0.84 1.43 0.58 1.05

9 1.48 0.68 1.48 0.80 0.95

10 1.65 0.82 1.65 0.82 1.15

11 1.71 1.06 1.71 0.65 1.30

S&M Average 1.07 0.55 0.94 0.32 0.99

Table 1: Elastic constants for the 11 isotropic layers used in the layered models in this paper.