1. Vernon Cormier Small Scale Heterogeneity: Seismic Observations and Wavefield Effects

2. Pulse attenuation and broadening Pulse postcursors (coda) and precursors SPO (shape preferred orientation) long wavelength equivalent medium BODY WAVE EFFECTS ka <= 1 (2  a/  <= 1)

3. DYNAMIC COMPOSITE ELASTIC MODULI: SCATTERING IMITATES VISCOELASTICITY Kaelin, B., and L.R. Johnson, J. Appl. Phys.,84(10), 1998 Frequency Attenuation V/V o

4. WAVEFORM EFFECTS OF FORWARD SCATTERING

5. Dispersion and Attenuation from Viscoelasticity Weaker dispersion Note: Viscoelastic shear modulus defect <= 25%, implying bounds on width of relaxation spectrum and viscoelastic attenuation. Modulus Defect

6. WAVEFORM EFFECTS OF INTRINSIC ATTENUATION Cormier, V.F., and X. Li, J.Geophys. Res., 107, 2362, doi:10.1029/2002JB001796, 2002.

7. Q INVERSION WITH SCATTERING MODEL Cormier, V.F., and X. Li, J.Geophys. Res., 107, 2362, doi:10.1029/2002JB001796, 2002. Inner Core

8. Observations of Heterogeneity Power Spectrum Note: missing information at scale lengths 1000 km to 1 km Global TomographyWell Logs/Exploration Wavenumber Power

9. S SS SSS 25 45 65 85 Distance (deg) S ScS sS sScS Figure 1 2-D High Frequency Pseudospectral Modeling Wavefield Snapshot Seismogram Record Section

10.  Vp/Vp = 0.3*  Vs/Vs SH and SV Model Near CMB SKS SScS

11. SH SV SScS Apparent Transverse Isotropy Cormier, V.F., EOS Trans. AGU, 84(46), Abstract S41E-0129, 2003. Komatitsch, D., L.P. Vinnik, and S. Chevrot, J. Geophys. Res., doi:10.1029/2009JB006795, in press.

12. Observations of Scattered PKIKP Precursors

13. Successful Models for PKIKP Precursors

14. Synthetic Seismograms with Rayleigh- Born Approximation in 3-D Cormier, V.F., Geophys. J. Int., 136, 373-384, 1999.

15. Model 2Low PassHigh Pass 0.0 -5.05.01.0-2.02.00.0 Figure 6 A Vanishing D” at Short Scale Lengths?

16. Model 3 Figure 11

17. Realization that Reproduces Coherent SdS: 3.1

18. CONCLUSIONS Small scale heterogeneity (0.1 to 10 km) can mimic viscoelasticty Estimated viscoelastic 1/Q’s are upper bounds to viscoelastic attenuation Isotropic distributions of small scale lengths can mimic SPO transverse isotropy Tests of the seismic wavefield effects of realistic mixing models are possible