Tomographic inversion for three-dimensional anisotropy of Earth's inner core

Physics of the Earth and Planetary Interiors

Volumn 167, Issue 1-2, 2008, Pages 53-70

  Sun, Xinlei ^a   Song, Xiaodong ^a  

^a UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN   (United States)

Author keywords

Inner inner core; Three dimensional inner core anisotropy; Three dimensional ray tracing

Indexed keywords

GEOCHEMISTRY; RAY TRACING; SEISMIC WAVES; SEISMOLOGY; STRUCTURAL GEOLOGY;

INNER CORE ANISOTROPY; SPLINE PARAMETERIZATION; TOMOGRAPHIC INVERSION;

GEOPHYSICS;

BODY WAVE; DATA INVERSION; INNER CORE; PARAMETERIZATION; RAY TRACING; SEISMIC ANISOTROPY; SEISMIC TOMOGRAPHY; THREE-DIMENSIONAL MODELING; TRAVEL TIME; WAVEFORM ANALYSIS;

EID: 42649134098     PISSN: 00319201     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.pepi.2008.02.011     Document Type: Article

References (75)

1. Beghein C., and Trampert J. Robust normal mode constraints on inner-core anisotropy from model space search. Science 299 (2003) 552-555
2. Breger L., Romanowicz B., and Tkalcic H. PKP(BC-DF) travel time residuals and short scale heterogeneity in the deep Earth. Geophys. Res. Lett. 26 20 (1999) 3169-3172
3. ″ on PKP(AB-DF) travel time residuals and possible implications for inner core structure. Earth Planet. Sci. Lett. 175 1-2 (2000) 133-143
4. Calvet M., Chevrot S., and Souriau A. P-wave propagation in transversely isotropic media. II. Application to inner core anisotropy: Effects of data averaging, parameterization and a priori information. Phys. Earth Planet. Inter. 156 1-2 (2006) 21-40
5. Cao A.M., and Romanowicz B. Constraints on density and shear velocity contrasts at the inner core boundary. Geophys. J. Int. 157 3 (2004) 1146-1151
6. Cao A.M., and Romanowicz B. Hemispherical transition of seismic attenuation at the top of the Earth's inner core. Earth Planet. Sci. Lett. 228 3-4 (2004) 243-253
7. Cao A.M., Masson Y., and Romanowicz B. Short wavelength topography on the inner-core boundary. Proc. Natl. Acad. Sci. U.S.A. 104 1 (2007) 31-35
8. Cao A.M., and Romanowicz B. Test of the innermost inner core models using broadband PKIKP travel time residuals. Geophys. Res. Lett. 34 8 (2007) L08303 doi:10.1029/2007GL029384
9. Cormier V.F., and Li X. Frequency-dependent seismic attenuation in the inner core. 2. A scattering and fabric interpretation. J. Geophys. Res. 107 B12 (2002) 2362 doi:10.1029/2002JB001796
10. Cormier V.F., and Stroujkova A. Waveform search for the innermost inner core. Earth Planet. Sci. Lett. 236 1-2 (2005) 96-105
11. Cormier V.F., Xu L., and Choy G.L. Seismic attenuation of the inner core: viscoelastic or stratigraphic?. Geophys. Res. Lett. 25 21 (1998) 4019-4022
12. Creager K.C. Anisotropy of the inner core from differential travel-times of the phases PKP and PKIKP. Nature 356 (1992) 309-314
13. Creager K.C. Inner core rotation rate from small-scale heterogeneity and time-varying travel times. Science 278 (1997) 1284-1288
14. Creager K.C. Large-scale variations in inner core anisotropy. J. Geophys. Res. 104 B10 (1999) 23127-23139
15. Durek J., and Romanowicz B. Inner core anisotropy inferred by direct inversion of normal mode spectra. Geophys. J. Int. 139 (1999) 599-622
16. Dziewonski A.M., and Anderson D.L. Preliminary reference Earth model. Phys. Earth Planet. Int. 25 4 (1981) 297-356
17. Dziewonski A.M., and Gilbert F. Effect of small, aspherical perturbations on travel times and a re-examination of corrections for ellipticity. Geophys. J. R. Astron. Soc. 44 1 (1976) 7-17
18. Garcia R. Constraints on upper inner-core structure from waveform inversion of core phases. Geophys. J. Int. 150 3 (2002) 651-664
19. Garcia R. Seismological and mineralogical constraints on the inner core fabric. Geophys. Res. Lett. 29 20 (2002) 1958 doi:10.1029/2002GL015268
20. Garcia R., and Souriau A. Inner core anisotropy and heterogeneity level. Geophys. Res. Lett. 27 19 (2000) 3121-3124
21. Ishii M., and Dziewonski A.M. The innermost inner core of the Earth: evidence for a change in anisotropic behavior at the radius of about 300 km. Proc. Natl. Acad. Sci. U.S.A. 99 22 (2002) 14026-14030
22. Ishii M., Tromp J., Dziewonski A.M., and Ekstrom G. Joint inversion of normal mode and body wave data for inner core anisotropy. 1. Laterally homogeneous anisotropy. J. Geophys. Res. 107 B12 (2002) 2379 doi:10.1029/2001JB000712
23. Ishii M., Dziewonski A.M., Tromp J., and Ekstrom G. Joint inversion of normal mode and body wave data for inner core anisotropy. 2. Possible complexities. J. Geophys. Res. 107 B12 (2002) 2380 doi:10.1029/2001JB000713
24. Karason H., and van der Hilst R.D. Tomographic imaging of the lowermost mantle with differential times of refracted and diffracted core phases (PKP, P-diff). J. Geophys. Res. 106 B4 (2001) 6569-6587
25. Kennett B.L.N., Engdahl E.R., and Buland R. Constraints on seismic velocities in the Earth from travel-times. Geophys. J. Int. 122 1 (1995) 108-124
26. Koketsu K., and Sekine S. Pseudo-bending method for three-dimensional seismic ray tracing in a spherical Earth with discontinuities. Geophys. J. Int. 132 2 (1998) 339-346
27. Koper K.D., Franks J.M., and Dombrovskaya M. Evidence for small-scale heterogeneity in Earth's inner core from a global study of PKiKP coda waves. Earth Planet. Sci. Lett. 228 3-4 (2004) 227-241
28. Laske, G., Masters, G., 2003. The Earth's free oscillation and differential rotation of the inner core. In: Dehant, V., Creager, K.C., Karato, S., Zatman, S. (Eds.), Earth's Core: Geodynamics, Structure, Rotation. Am. Geophys. Union, Geodyn. Ser. 31, 5-21.
29. Li, C., van der Hilst, R.D., Engdahl, E.R., submitted for publication. A new global model for P wavespeed variations in Earth's mantle. Geochem. Geophys. Geosyst. doi:10.1029/2007GC001806.
30. Liang C.T., Song X.D., and Huang J.L. Tomographic inversion of Pn travel times in China. J. Geophys. Res. 109 B11 (2004) B11304 doi:10.1029/2003JB002789
31. Luo S.N., Ni S.D., and Helmberger D.V. Evidence for a sharp lateral variation of velocity at the core-mantle boundary from multipathed PKPab. Earth Planet. Sci. Lett. 189 3-4 (2001) 155-164
32. Michelini A., and Mcevilly T.V. Seismological studies at Parkfield. 1. Simultaneous inversion for velocity structure and hypocenters using cubic B-splines parameterization. Bull. Seismol. Soc. Am. 81 2 (1991) 524-552
33. Morelli A., Dziewonski A.M., and Woodhouse J.H. Anisotropy of the inner core inferred from PKIKP travel-times. Geophys. Res. Lett. 13 13 (1986) 1545-1548
34. Niu F.L., and Wen L.X. Hemispherical variations in seismic velocity at the top of the Earth's inner core. Nature 410 (2001) 1081-1084
35. Ouzounis A., and Creager K.C. Isotropy overlying anisotropy at the top of the inner core. Geophys. Res. Lett. 28 22 (2001) 4331-4334
36. Paige C.C., and Saunders M.A. LSQR-an algorithm for sparse linear-equations and sparse least-squares. ACM Trans. Math. Softw. 8 1 (1982) 43-71
37. Poupinet G., Souriau A., and Jenatton L. A test on the Earth's core mantle boundary structure with antipodal data-example of Fiji-Tonga earthquakes recorded in Tamanrasset, Algeria. Geophys. J. Int. 113 3 (1993) 684-692
38. Romanowicz B., Li X.D., and Durek J. Anisotropy in the inner core: could it be due to low-order convection?. Science 274 (1996) 963-966
39. Romanowicz B. Global mantle tomography: progress status in the past 10 years. Annu. Rev. Earth Planet. Sci. 31 (2003) 303-328
40. Shearer P.M. Constraints on inner-core anisotropy from PKP(DF) travel-times. J. Geophys. Res. 99 B10 (1994) 19647-19659
41. Song X.D. Anisotropy in central part of inner core. J. Geophys. Res. 101 B7 (1996) 16089-16097
42. Song X.D. Anisotropy of the Earth's inner core. Rev. Geophys. 35 3 (1997) 297-313
43. Song, X.D., Dai, W., submitted for publication. Topography of inner core boundary from high-quality waveform doublets. Geophys. J. Int.
44. Song X.D., and Helmberger D.V. Anisotropy of Earth's inner-core. Geophys. Res. Lett. 20 23 (1993) 2591-2594
45. Song X.D., and Helmberger D.V. Effect of velocity structure in D" on PKP phases. Geophys. Res. Lett. 20 4 (1993) 285-288
46. Song X.D., and Helmberger D.V. Depth dependence of anisotropy of Earth's inner-core. J. Geophys. Res. 100 B6 (1995) 9805-9816
47. Song X.D., and Helmberger D.V. A P-wave velocity model of Earth's core. J. Geophys. Res. 100 B6 (1995) 9817-9830
48. Song X.D., and Helmberger D.V. PKP differential travel times: Implications for 3-D lower mantle structure. Geophys. Res. Lett. 24 15 (1997) 1863-1866
49. Song X.D., and Helmberger D.V. Seismic evidence for an inner core transition zone. Science 282 (1998) 924-927
50. Song X.D., and Poupinet G. Inner core rotation from event-pair analysis. Earth Planet. Sci. Lett. 261 (2007) 259-266
51. Song X.D., and Richards P.G. Seismological evidence for differential rotation of the Earth's inner core. Nature 382 (1996) 221-224
52. Song X.D., and Xu X.X. Inner core transition zone and anomalous PKP(DF) waveforms from polar paths. Geophys. Res. Lett. 29 4 (2002) 1042 doi:10.1029/2001GL013822
53. Souriau A., and Poupinet G. The velocity profile at the base of the liquid core from PKP(BC + Cdiff) data-an argument in favor of radial inhomogeneity. Geophys. Res. Lett. 18 11 (1991) 2023-2026
54. Su W.J., and Dziewonski A.M. Inner-core anisotropy in 3 dimensions. J. Geophys. Res. 100 (1995) 9831-9852
55. Sun X.L., Poupinet G., and Song X.D. Examination of systematic mislocation of south sandwich islands earthquakes using station pairs: implications for inner core rotation. J. Geophys. Res. 111 B11 (2006) B11305 doi:10.1029/2005JB004175
56. Sun X.L., and Song X.D. PKP travel times at near antipodal distances: Implications for inner core anisotropy and lowermost mantle structure. Earth Planet. Sci. Lett. 199 3-4 (2002) 429-445
57. Sun, X.L., Song, X.D., 2004. Is there an innermost inner core? EOS Trans. AGU 85 (47) (Fall Meet. Suppl., Abstract T54A-05).
58. Sun, X.L., Song, X.D., submitted for publication. The inner inner core of the Earth: texturing of iron crystals from three-dimensional seismic anisotropy. Earth Planet. Sci. Lett. doi:10.1016/j.epsl.2008.01.049.
59. Sun X.L., Song X.D., Zheng S.H., and Helmberger D.V. Evidence for a chemical-thermal structure at base of mantle from sharp lateral P-wave variations beneath Central America. Proc. Natl. Acad. Sci. U.S.A. 104 1 (2007) 26-30
60. Tanaka S., and Hamaguchi H. Degree one heterogeneity and hemispherical variation of anisotropy in the inner core from PKP(BC)-PKP(DF) times. J. Geophys. Res. 102 B2 (1997) 2925-2938
61. Tkalcic H., Romanowicz B., and Houy N. Constraints on D" structure using PKP(AB-DF), PKP(BC-DF) and PcP-P travel time data from broad-band records. Geophys. J. Int. 149 3 (2002) 599-616
62. Tromp J. Support for anisotropy of the Earth's inner-core from free oscillations. Nature 366 (1993) 678-681
63. Um J., and Thurber C. A fast algorithm for 2-point seismic ray tracing. Bull. Seismol. Soc. Am. 77 3 (1987) 972-986
64. van der Hilst R.D., Widiyantoro S., and Engdahl E.R. Evidence for deep mantle circulation from global tomography. Nature 386 (1997) 578-584
65. Vidale J.E., Dodge D.A., and Earle P.S. Slow differential rotation of the Earth's inner core indicated by temporal changes in scattering. Nature 405 (2000) 445-448
66. Vidale J.E., and Earle P.S. Fine-scale heterogeneity in the Earth's inner core. Nature 404 (2000) 273-275
67. Vinnik L., Romanowicz B., and Breger L. Anisotropy in the center of the inner-core. Geophys. Res. Lett. 21 16 (1994) 1671-1674
68. Wen L.X. Localized temporal change of the Earth's inner core boundary. Science 314 (2006) 967-970
69. Widiyantoro S., Gorbatov A., Kennett B.L.N., and Fukao Y. Improving global shear wave travel time tomography using three-dimensional ray tracing and iterative inversion. Geophys. J. Int. 141 (2000) 747-758
70. Woodhouse J.H., Giardini D., and Li X.D. Evidence for inner core anisotropy from free oscillations. Geophys. Res. Lett. 13 13 (1986) 1549-1552
71. Yu W.C., and Wen L.X. Inner core attenuation anisotropy. Earth Planet. Sci. Lett. 245 3-4 (2006) 581-594
72. Yu W.C., Wen L.X., and Niu F.L. Seismic velocity structure in the Earth's outer core. J. Geophys. Res. 110 B2 (2005) 02302
73. Zhang J., Song X.D., Li Y.C., Richards P.G., Sun X.L., and Waldhauser F. Inner core differential motion confirmed by earthquake waveform doublets. Science 309 (2005) 1357-1360
74. Zhao D.P., Hasegawa A., and Horiuchi S. Tomographic imaging of P-wave and S-wave velocity structure beneath northeastern Japan. J. Geophys. Res. 97 B13 (1992) 19909-19928
75. Zheng S.H., Sun X.L., and Song X.D. Fine structure of P-wave velocity variations underneath the Central Pacific from PKP waves recorded at the China Seismic Network (CSN). Chin. J. Geophys. 50 1 (2007) 183-191