1. 3D seismic imaging of the earth’s mantle Barbara Romanowicz Department of Earth and Planetary Science U.C. Berkeley

3. Surface waves

4. P P S SS Surface waves Loma Prieta (CA) 1989 M 7 earthquake observed at KEV, Finland

6. Shearer, 1991 Global Transverse Component Stacks

8. After Park et al, 2005

9. Sumatra 12/26/04 M9.3 (0.8 to 2.2 mHz) CAN UNM 0S7 0S9 3S2 0S6 1S4 0S11 1S5 1S3 /3S1 0S8 0S5 0S0 200 hours starting 10 hours before origin time 0S10 0S12 mHz x10 0S5 0S13

11. PRELIMINARY REFERENCE EARTH MODEL (PREM) Dziewonski and Anderson, 1981 Radius [km] Solid Inner Core Liquid Outer Core Lower Mantle Upper mantle 637112103480 0 5700

16. ( Albarède and van der Hilst, 1999

17. Van der Hilst et al., 1998 P-wave travel time tomography

19. SH SV S wave tomography

20. Montagner, 2002  = (Vsh/Vsv) 2 Seismic Anisotropy

21. Motivation for seismic Q tomography: Faul and Jackson, 2005

22. 3D Shear Velocity Models

23. “SH models” “SV models” Gung et al., 2003

24. S velocity Model: SAW24B16

25. ABCD “ Pacific Superplume” Q -1 Hawaii

26. MNST African “superplume” Elastic SAW24B16 Q -1

27. Panning and Romanowicz, 2004 ISOTROPIC VELOCITY RADIAL ANISOTROPY  = (V SH /V SV ) 2

28. Wang and Wen, 2005 dlnVs ~ -3- -12% Ni and Wen, 2005 African Superplume

29. Vs VV  Ishii and Tromp, 2000 Depth ~ 2800 km

30. Garnero, 1998

31. Courtillot et al., 2003

32. The Earth’s inner core

34. Anomalous splitting of core sensitive modes Data Model

35. Mantle mode Core mode

36. (Tanaka and Hamaguchi, 1995) Hemispherical dependence of anisotropy

37. Garcia and Souriau, 2002

38. Innermost Inner Core ? Ishii and Dziewonski, 2003

39. Differential rotation of the Inner Core

40. Published by AAAS J. Zhang et al., Science 309, 1357 -1360 (2005) Fig. 1. Ray paths of PKP waves and example of waveform doublet used to detect temporal change of travel times through the inner core

41. Published by AAAS J. Zhang et al., Science 309, 1357 -1360 (2005) Fig. 1. Ray paths of PKP waves and example of waveform doublet used to detect temporal change of travel times through the inner core

42. Published by AAAS J. Zhang et al., Science 309, 1357 -1360 (2005) Fig. 4. Difference of BC - DF times, d(BC - DF), at station COL as a function of the time separation between the two events of the doublet

43. Bréger et al., EPSL, 2000 Map: enhanced tomographic map at The core-mantle boundary STRONG MANTLE HETEROGENEITY?

44. Current Challenges Improving resolution of 3D structure: –Wave propagation in strongly heterogeneous 3D media/waveform inversion –Address uneven sampling (oceans) –Fine scale structure of major discontinuities Attenuation tomography 3D density structure Combining information from seismology, mineral physics, geochemistry and geodynamics

45. Cartoon from Cazenave, 2002

46. Garnero, Ann. Rev. 2000 “Scenario for CMB”

47. Cartoon from Hellfrich and Wood, 2001

48. “SH models” “SV models”

49. Fukao et al., 2001

50. 175 km 300 km Transverse isotropy dln   = Vsh/Vsv

51. - 0 - 100 - 200 - 300 - 400 km

52. Upper mantle:Q - lower mantle: Vsh Degree 2 only

54. QRLW8 Hotspot distribution Weighted by buoyancy flux Attenuation tomography

55. Anelastic attenuation: QRLW8 Gung and Romanowicz, 2002