Reconciling the post-perovskite phase with seismological observations of lowermost mantle structure

Geophysical Monograph Series

Volumn 174, Issue , 2007, Pages 129-153

  Lay, Thorne ^a   Garnero, Edward J ^b  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b ARIZONA STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 84899652759     PISSN: 00658448     EISSN: 23288779     Source Type: Book Series    
DOI: 10.1029/174GM11     Document Type: Chapter

References (224)

1. 3 perovskite to post-perovskite phase transition, Geophys. Res. Lett., 32, L14303, doi: 10.1029/2005GL023192, 2005.
2. Antolik, M., Y.J. Gu, and G. Ekström, J362D28: A new joint model of compressional and shear velocity in the Earth’s mantle, Geophys. J. Int., 153,443-466, 2003.
3. Avants, M., T. Lay, and E.J. Garnero, A new probe of ULVZ S-wave velocity structure: array stacking of ScS waveforms, Geophys. Res. Lett., 33, L07314, doi:10.1029/2005GL024989, 2006a.
4. Avants, M., T. Lay, S.A. Russell, and E.J. Garnero, Shear-velocity variation within the D″ region beneath the Central Pacific, J. Geophys. Res., 111, B05305, doi:10.1029/2004JB003270, 2006b.
5. Badro, J., G. Fiquet, F. Guyot, J.-P. Rueff, V.V. Struzhkin, G. Vankó, and G. Monaco, Iron partitioning in Earth’s mantle: Toward a deep lower mantle discontinuity, Science, 300,789-791, 2003.
6. Badro, J., J.-P. Rueff, G. Vankó, G. Monaco, G. Fiquet, and F. Guyot, Electronic transitions in perovskite: Possible nonconvecting layers in the lower mantle, Science, 305,383-386, 2004.
7. Becker, T.W., and L. Boschi, A comparison of tomographic and geodynamic mantle models, Geochem., Geophys., Geosys., 3, 2001GC000168, 2002.
8. Bijwaard, H., W. Spakman, and E.R. Engdahl, Closing the gap between regional and global travel time tomography, J. Geophys. Res., 103, 30,055-30,078, 1998.
9. Bilek, S.L., and T. Lay, Lower mantle heterogeneity beneath Eurasia imaged by parametric migration of shear waves, Phys. Earth Planet. Int., 108,201-218, 1998.
10. Boschi, L., and A.M. Dziewonski, High-and low-resolution images of the Earth’s mantle: Implications of different approaches to tomographic modeling, J. Geophys. Res., 104, 25,567-25,594, 1999.
11. Boschi, L., and A.M. Dziewonski, Whole Earth tomography from delay times of P, PcP, and PKP phases: Lateral heterogeneities in the outer core or radial anisotropy in the mantle?, J. Geophys. Res., 105, 13,675-13,696, 2000.
12. 3-FeSiO3-Al2O3 system and implications for the lowermost mantle, Geophys. Res. Lett., 32, L16310, doi:10.1029/2005GL023164, 2005.
13. Castle, J.C., K.C. Creager, J.P. Winchester, and R.D. van der Hilst, Shear wave speeds at the base of the mantle, J. Geophys. Res., 105, 21,543-21,557, 2000.
14. Chambers, K., and J.H. Woodhouse, Investigating the lowermost mantle using migrations of long-period S-ScS data, Geophys. J. Int., 106, 667-678, 2006a.
15. Chambers, K., and J.H. Woodhouse, Transient D″ discontinuity revealed by seismic migration, Geophys. Res. Lett., 33, L17312, doi:10.1029/2006 GL027043, 2006b.
16. Davis, J.P., and M. Weber, Lower mantle velocity inhomogeneity observed at GRF array, Geophys. Res. Lett., 17,187-190, 1990.
17. Ding, X., and D.V. Helmberger, Modeling D″ structure beneath Central America with broadband seismic data, Phys. Earth Planet. Inter., 101,245-270, 1997.
18. Doornbos, D.J., and T. Hilton, Models of the core-mantle boundary and the travel times of internally reflected core phases, J. Geophys. Res., 94, 15,741-15,751, 1989.
19. Dziewonski, A.M., Mapping the lower mantle: Determination of lateral heterogeneity in P velocity up to degree and order 6, J. Geophys. Res., 89,5929-5942, 1984.
20. Dziewonski, A.M., and D.L. Anderson, Preliminary reference Earth model, Phys. Earth Planet. Inter., 25,297-356, 1981.
21. Dziewonski, A.M., B.H. Hager, and R.J. O’Connell, Large scale heterogeneity in the lower mantle, J. Geophys. Res., 82,239-255, 1977.
22. 3 perovskite at lower mantle pressure and temperature conditions, Geophys. Res. Lett., 27,21-24, 2000.
23. Flores, C., and T. Lay, The trouble with seeing double, Geophys. Res. Lett., 32, L24305, doi:10.1029/2005GL024366, 2005.
24. Ford, S.R., E.J. Garnero, and A.K. McNamara, A strong lateral shear velocity gradient and anisotropy heterogeneity in the lowermost mantle beneath the southern Pacific, J. Geophys. Res., 111, B03306, doi:10.1029/ 2004JB003574, 2006.
25. Fouch, M.J., K.M. Fischer, and M.E. Wysession, Lowermost mantle anisotropy beneath the Pacific: imaging the source of the Hawaiian plume, Earth Planet. Sci. Lett., 190,167-180, 2001.
26. Freybourger, M., F. Krüger, and U. Achauer, A 22 long seismic profile for the study of the top of D″, Geophys. Res., Lett., 26,3409-3412, 1999.
27. Fukao, Y., S. Widiyantori, and M. Obayashi, Stagnant slabs in the upper and lower mantle transition region, Rev. of Geophys., 39,291-323, 2001.
28. Gaherty, J.B., and T. Lay, Investigation of laterally heterogeneous shear velocity structure in D″ beneath Eurasia, J. Geophys. Res., 97,417-435, 1992.
29. Garcia, R., and A. Souriau, Amplitude of the core-mantle boundary topography estimated by stochastic analysis of core phases, Phys. Earth Planet. Inter., 117,345-359, 2000.
30. Garnero, E.J., Heterogeneity of the lowermost mantle, Annu. Rev. Earth Planet. Sci., 28,509-537, 2000.
31. Garnero, E.J., and D.V. Helmberger, A very slow basal layer underlying large-scale low velocity anomalies in the lower mantle beneath the Pacific: Evidence from core phases, Phys. Earth Planet. Inter., 91,161-176, 1995.
32. Garnero, E.J., and D.V. Helmberger, Further structural constraints and uncertainties of a thin laterally varying ultralow-velocity layer at the base of the mantle, J. Geophys. Res., 103, 12,495-12,509, 1998.
33. Garnero, E.J., and T. Lay, Lateral variations in the lowermost mantle shear wave anisotropy beneath the north Pacific and Alaska, J. Geophys. Res., 102,8121-8135, 1997.
34. Garnero, E.J., and T. Lay, Effects of D″ anisotropy on seismic velocity models of the outermost core, Geophys. Res. Lett., 25,2341-2344, 1999.
35. Garnero, E.J., and T. Lay, D″ shear velocity heterogeneity, anisotropy and discontinuity structure beneath the Caribbean and Central America, Phys. Earth Planet. Inter., 140,219-242, 2003.
36. Garnero, E.J., D.V. Helmberger, and G. Engen, Lateral variation near the core-mantle boundary, Geophys. Res. Lett., 20,1843-1846, 1988.
37. Garnero, E.J., D.V. Helmberger, and S. Grand, Preliminary evidence for a lower mantle shear wave velocity discontinuity beneath the central Pacific, Phys. Earth Planet. Inter., 79, 335-347, 1993a.
38. Garnero, E.J., S.P. Grand, and D.V. Helmberger, Low P-wave velocity at the base of the mantle, Geophys. Res. Lett., 20, 1843-1846, 1993b.
39. Garnero, E.J., T. Lay, and A. McNamara, Implications of lower mantle structural heterogeneity for existence and nature of whole mantle plumes, In:The Origin of Melting Anomalies: Plates, Plumes and Planetary Processes, Foulger, G.R., and D.M. Jurdy (eds.), in press, 2006.
40. Garnero, E.J., V. Maupin, T. Lay, and M.J. Fouch, Variable azimuthal anisotropy in Earth’s lowermost mantle, Science, 306, 259-261, 2004a.
41. Garnero, E.J., M.M. Moore, T. Lay, and M.J. Fouch, Isotropy or weak vertical transverse isotropy in D″ beneath the Atlantic Ocean, J. Geophys. Res., 109, B08308, doi:10.1029/2004JB003004, 2004b.
42. Garnero, E.J., J.S. Revenaugh, Q. Williams, T. Lay, and L.H. Kellogg, Ultralow velocity zone at the core-mantle boundary. In: Gurnis, M., M.E. Wysession, E. Knittle, and B.A. Buffett (eds.) The Core-Mantle Boundary Region. American Geophysical Union, Washington, D.C., pp 319-334, 1998.
43. Gong, Z., Y. Fei, F. Dai, L. Zhang, and F. Jing, Equation of state and phase stability of mantle perovskite up to 140 GPa shock pressure and its geophysical implications, Geophys. Res. Lett., 31, L04614, doi:10.1029/2003 GL019132, 2004.
44. Grand, S.P., Mantle shear-wave tomography and the fate of subducted slabs, Phil. Trans. R. Soc. Lond., A, 360,2475-2491, 2002.
45. Gu, Y.J., A.M. Dziewonski, W. Su, and G. Ekström, Models of the mantle shear velocity and discontinuities in the pattern of lateral heterogeneities, J. Geophys. Res., 106, 11,169-11,199, 2001.
46. He, Y., L. Wen, and T. Zheng, Geographic boundary and shear wave velocity structure of the “Pacific anomaly” near the core-mantle boundary beneath western Pacific, Earth Planet. Sci. Lett., 244,302-314, 2006.
47. Helmberger, D.V., T. Lay, S. Ni, and M. Gurnis Deep mantle structure and the post-perovskite phase transition, Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502504102., 2005.
48. Hernlund, J.W., and S. Labrosse, Geophysically consistent values of the perovskite to post-perovskite transition Clapeyron slope, Geophys. Res. Lett., 234, L05309, doi:10.1029/2006GL028961, 2007.
49. Hernlund, J.W., C. Thomas, and P.J. Tackley, A doubling of the post-perovskite phase boundary and structure of the Earth’s lowermost mantle, Nature, 434,882-886, 2005.
50. Hirose, K., Postperovskite phase transition and its geophysical implications, Rev. of Geophys., 44, RG3001, doi:10.1029/ 2005RG000186, 2006.
51. 3, Geophys. Res. Lett., 32, L13313, doi:10.1029/2005 GL023219, 2005.
52. Hirose, K., N. Takafuji, N. Sata, and Y. Ohishi, Phase transition and density of subducted MORB crust in the lower mantle, Earth Planet. Sci. Lett., 237, 239-251, 2005a.
53. Hirose, K., K. Kawamura, Y. Ohishi, S. Tateno, and N. Sata, Stability and equation of state of MgGeO3 post-perovskite phase, Am. Mineral., 90, 262-265, 2005b.
54. 3 using Au and MgO internal pressure standards, Geophys. Res. Lett., 33, L01310, doi:10.1029/2005 GL024468, 2006.
55. Houard, S., and H.C. Nataf, Further evidence for the “Lay discontinuity” beneath northern Siberia and the North Atlantic from short-period Pwaves recorded in France, Phys. Earth Planet. Inter., 72,264-275, 1992.
56. Houard, S., and H.C. Nataf, Laterally varying reflector at the top of D″ beneath northern Siberia, Geophys. J. Int., 115,168-182, 1993.
57. Hutko, A., T. Lay, E.J. Garnero, and J.S. Revenaugh. Seismic detection of folded, subducted lithosphere at the core-mantle boundary, Nature, 441,333-336, 2006.
58. 3 post-perovskite phase in the Earth’s lowermost mantle, Nature, 430,442-445, 2004.
59. Ishii, M., and J. Tromp, Normal-mode and free-air gravity constraints on lateral variations in velocity and density of Earth’s mantle, Science, 285,1231-1236, 1999.
60. Ishii, M., and J. Tromp, Constraining large-scale mantle heterogeneity using mantle and inner-core sensitive normal modes, Phys. Earth Plan. Int., 146,113-124, 2004.
61. Ito, E., and E. Takahashi, Postspinel transforms in the system Mg2SiO4-Fe2SiO4 and some geophysical implications, J. Geophys. Res., 94, 10,637-10,646, 1989.
62. Ito, E., and H. Yamada, Stability relations of silicate spinels, ilmenites and perovskites, in High Pressure Research in Geophysics, edited by S. Akimoto and M.H. Manghani, Tokyo, pp. 405-419, 1982.
63. Jackson, I., and S.M. Rigden, Composition and temperature of the Earth’s mantle: Seismological models interpreted through experimental studies of Earth materials, in “The Earth’s Mantle-Composition, Structure and Evolution”, I. Jackson, ed., pp. 405-460, Cambridge University Press, 1998.
64. Karáson, H., and R.D. van der Hilst, Tomographic imaging of the lowermost mantle with differential times of refracted and diffracted core phases (PKP, Pdiff), J. Geophys. Res., 106,6569-6587, 2001.
65. Karato, S.-I., Some remarks on the origin of seismic anisotropy in the D″ layer, Earth Planets Space, 50,1019-1028, 1998.
66. Kendall, J.M., Seismic anisotropy in the boundary layers of the mantle, In:Earth’s Deep Interior: Mineral Physics and Tomography From the Atomic to the Global Scale, Karato, S.-I., A.M. Forte, R.C. Liebermann, G. Masters, and L. Stixrude (eds.), pp. 133-159, American Geophysical Union, Washington, D.C, 2000.
67. Kendall, J.-M., and C. Nangini, Lateral variations in D″ below the Caribbean, Geophys. Res. Lett., 23,399-402, 1996.
68. Kendall, J.-M., and P.M. Shearer, Lateral variations in D″ thickness from long-period shear wave data, J. Geophys. Res., 99, 11,575-11,590, 1994.
69. Kendall, J.-M., and P.M. Shearer, On the structure of the lowermost mantle beneath the southwest Pacific, southeast Asia and Australasia, Phys. Earth Planet. Int., 92,85-98, 1995.
70. Kendall, J.M., and P.G. Silver, Constraints from seismic anisotropy on the nature of the lowermost mantle, Nature, 381,409-412, 1996.
71. Kennett, B.L.N., S. Widiyantoro, and R.D. van der Hilst, Joint seismic tomography for bulk sound and shear wave speed in the Earth’s mantle, J. Geophys. Res., 103, 12,469-12,493, 1998.
72. Kito, T., and F. Krüger, Heterogeneities in D″ beneath the southwestern Pacific inferred from scattered and reflected P-waves, Geophys. Res. Lett., 28,2545-2548, 2001.
73. Kito, T., F. Krüger, and H. Negishi, Seismic heterogeneous structure in the lowermost mantle beneath the southwestern Pacific, J. Geophys. Res., 109, B09304, doi:10.1029/20023JB002677, 2004.
74. Knittle, E., and R. Jeanloz, Synthesis and equation of state of (Mg,Fe)SiO3 perovskite to over 100 gigapascals, Science, 235,668-670, 1987.
75. 3 postperovskite, perovskite, and magnesiowüstite in the Earth’s lower mantle, Geophys. Res. Lett., 32, L19301, doi:10.1029/2005GL023257, 2005.
76. Kohler, M.D., J.E. Vidale, and P.M. Davis, Complex scattering within D″ observed on the very dense Los Angeles Region Seismic Experiment passive array, Geophys. Res. Lett., 24,1855-1858, 1997.
77. Krüger, F., M. Weber, F. Scherbaum, and J. Schlittenhardt, Normal and inhomogeneous lowermost mantle and core-mantle boundary under the Arctic and Northern Canada, Geophys. J. Int., 122,637-658, 1995.
78. Kuo, B.Y., E.J. Garnero, and T. Lay, Tomographic inversion of S-SKS times for shear velocity heterogeneity in D″: Degree 12 and hybrid models, J. Geophys. Res., 105, 28,139-28,157, 2000.
79. Kuo, C., and B. Romanowicz, On the resolution of density anomalies in the Earth’s mantle using spectral fitting of normal-mode data, Geophys. J. Int., 150,162-179, 2002.
80. Lay, T., and E.J. Garnero Core-mantle boundary structures and processes. In:R.S.J. Sparks, and C.J. Hawkesworth (eds.), The State of the Planet:Frontiers and Challenges in Geophysics. Geophysical Monograph Series, 150, IUGG Volume 19, pp. 25-41, 2004.
81. Lay, T., and D.V. Helmberger, A lower mantle S-wave triplication and the velocity structure of D″, Geophys. J. R. Astron. Soc., 75, 799-837, 1983a.
82. Lay, T., and D.V. Helmberger, The shear wave velocity gradient at the base of the mantle, J. Geophys. Res., 88, 8160-8170, 1983b.
83. Lay, T., and C.J. Young, Waveform complexity in teleseismic broadband SH displacements: slab diffractions or deep mantle reflections? Geophys. Res. Lett., 16,605-608, 1989.
84. Lay, T., and C.J. Young, Analysis of seismic SV waves in the core’s penumbra, Geophys. Res. Lett., 18,1373-1376, 1991.
85. Lay, T., and C.J. Young, Imaging scattering structures in the lowr mantle by migration of long-period S waves, J. Geophys. Res., 101, 20,023-20,040, 1996.
86. Lay, T., E.J. Garnero, and S.A. Russell Lateral variation of the D″ discontinuity beneath the Cocos Plate, Geophys. Res. Lett., 31, L15612, doi:10.1029/2004GL020300, 2004a.
87. Lay, T., E.J. Garnero, and Q. Williams, Partial melting in a thermo-chemical boundary layer at the base of the mantle, Phys. Earth Planet. Inter., 146, 441-467, 2004b.
88. Lay, T., Q. Williams, and E.J. Garnero, The core-mantle boundary layer and deep earth dynamics, Nature, 392, 461-468, 1998a.
89. Lay, T., E.J. Garnero, C.J. Young, and J.B. Gaherty, Scale-lengths of shear velocity heterogeneity at the base of the mantle from S-wave differential travel times, J. Geophys. Res., 102,9887-9910, 1997.
90. Lay, T., J. Hernlund, E.J. Garnero, and M. Thorne, A post-perovskite lens and D″ heat flux beneath the central Pacific, Science, 314,1272-1276, 2006.
91. Lay, T., Q. Williams, E.J. Garnero, L. Kellogg, and M.E. Wysession, Seismic wave anisotropy in the D″ region and its implications. In: The Core-Mantle Boundary Region, Gurnis, M., M.E. Wysession, E. Knittle, and B.A. Buffett (eds.). pp. 299-318, American Geophysical Union, Washington, D.C., 1998b.
92. Lay, T., D. Heinz, M. Ishii, S.-H. Shim, T. Tsuchiya, J. Tsuchiya, R. Wentzcovich, and D. Yuen, Multidisciplinary impact of the lower mantle perovskite phase transition, EOS, Trans. American Geophysical Union, 86, pp. 1, 5, 2005.
93. Lin, J.-F., V.V. Struzhkin, S.D. Jacobsen, M.Y. Hu, P. Chow, J. Kung, H. Liu, H.-k. Mao, and R.J. Hemley, Spin transition of iron in magnesiowustite in the Earth’s lower mantle, Nature, 436,377-380, 2005.
94. Liu, X.-F., J. Tromp, and A.M. Dziewonski, Is there a first-order discontinuity in the lowermost mantle?, Earth Planet. Sci. Lett., 160,343-351, 1998.
95. Luo, S.-N., S. Ni, and D.V. Helmberger, Evidence for a sharp lateral variation of velocity at the core-mantle boundary from multipathed PKPab, Earth Planet. Sci. Lett., 189,155-164, 2001.
96. Mainprice, D., G. Barruol, and W. Ben Ismail, The seismic anisotropy of the Earth’s mantle: from single crystal to polycrystal, In: Earth’s Deep Interior: Mineral Physics and Tomography From the Atomic to the Global Scale, Karato, S.-I., A.M. Forte, R.C. Liebermann, G. Masters, and L. Sixrude (eds.), pp. 237-264, American Geophysical Union, Washington, D.C., U.S.A, 2000.
97. Mao, W.L., G. Shen, V.B. Prakapenka, Y. Meng, A.J. Campbell, D.L. Heinz, J. Shu, R.J. Hemley, and H.K. Mao, Ferromagnesian postperovskite silicates in the D″ layer of the Earth, Proc. Natl. Acad. Sci. U. S. A., 101, 15, 867-15,869, 2004.
98. Mao, W.L., H.-K. Mao, W. Sturhahn, J. Zhao, V.B. Prakapenka, Y. Meng, J. Shu, Y. Fei, and R.J. Hemley, Iron-rich post-perovskite and the origin of ultralow-velocity zones, Science, 312,564-565, 2006.
99. Masters, G., G. Laske, H. Bolton, and A.M. Dziewonski, The relative behavior of shear velocity, bulk sound speed, and compressional velocity in the mantle: implications for chemical and thermal structure. In: Earth’s Deep Interior: Mineral Physics and Tomography From the Atomic to the Global Scale, S.-I. Karato, A.M. Forte, R.C. Liebermann, G. Masters, and L. Stixrude (Eds.), AGU, Washington, D.C., U.S.A., pp 63-87, 2000.
100. Matzel, E., M.K. Sen, and S.P. Grand, Evidence for anisotropy in the deep mantle beneath Alaska, Geophys. Res. Lett., 23,2417-2420, 1996.
101. Maupin, V., E.J. Garnero, T. Lay, and M.J. Fouch, Azimuthal anisotropy in the D″ layer beneath the Caribbean, J. Geophys. Res., 110, B08301, doi:10.1029/2004JB003506, 2005.
102. Mégnin, C., and B. Romanowicz, The three-dimensional shear velocity structure of the mantle from the inversion of body, surface, and highermode waveform, Geophys. J. Int., 143,709-728, 2000.
103. Merkel, S., A. Kubo, L. Miyagi, S. Speziale, T.S. Duffy, H.-K. Mao, and H.-R. Wenk, Plastic deformation of MgGeO3 post-perovskite at lower mantle pressures, Science, 311,644-646, 2006.
104. Mitchell, B.J., and D.V. Helmberger, Shear velocities at the base of the mantle from observations of S and ScS, J. Geophys. Res., 78,6009-6020, 1973.
105. Moore, M.M., E.J. Garnero, T. Lay, and Q. Williams, Shear wave splitting and waveform complexity for lowermost mantle structures with lowvelocity lamellae and transverse isotropy, J. Geophys. Res., 109, B02319, doi:10.1029/2003JB002546, 2004.
106. Mori, J., and D.V. Helmberger, Localized boundary layer below the mid-Pacific velocity anomaly identified from a PcP precursor, J. Geophys. Res., 100, 20,359-20,365, 1995.
107. 3, Science, 304,855-858, 2004.
108. Murakami, M., K. Hirose, N. Sata, and Y. Ohishi, Post-perovskite phase transition and mineral chemistry in the pyrolitic lowermost mantle, Geophys. Res. Lett., 32, L03304, doi: 10.1029/2004GL021956, 2005.
109. Ni, S., and D.V. Helmberger, Seismological constraints on the South African superplume; could be the oldest distinct structure on earth, Earth Planet. Sci. Lett., 206, 119-131, 2003a.
110. Ni, S., and D.V. Helmberger, Ridge-like lower mantle structure beneath South Africa, J. Geophys. Res., 108, B2, 2094, doi:10.1029/2001JB001545, 2003b.
111. Ni, S., X. Ding, and D.V. Helmberger, Constructing Synthetics from Deep Earth Tomographic Models, Geophys. J. Int., 140,71-82, 2000.
112. Ni, S., D.V. Helmberger, and J. Tromp, Three-dimensional structure of the Africa superplume from waveform modeling, Geophys. J. Int., 161,283-294, 2005.
113. Ni, S., E. Tan, M. Gurnis, and D.V. Helmberger, Sharp sides to the African superplume, Science, 296,1850-1852, 2002.
114. 3 in Earth’s D″ layer, Nature, 430,445-448, 2004.
115. 3 postperovskite phase, Nature, 438,1142-1144, 2005.
116. Ohta, K., K. Hirose, T. Lay, N. Sata, and Y. Ohishi, Evidence for a MORBrich pile in the Earth’s core-mantle boundary region, Earth Planet. Sci., submitted, 2006.
117. 3 and pyrolitic mantle composition, Earth Planet. Sci. Lett. 236,914-932, 2005.
118. Panning, M.P., and B. Romanowicz, Inferences on flow at the base of Earth’s mantle based on seismic anisotropy, Science, 303,351-353, 2004.
119. Pulliam, J., and M.K. Sen, Seismic anisotropy in the core-mantle transition zone, Geophys. J. Int., 135,113-128, 1998.
120. Reasoner, C., and J. Revenaugh, Short-period P-wave constraints on D″ reflectivity, J. Geophys. Res., 104,955-961, 1999.
121. Reif, C., Constraints on the presence or absence of post-perovskite in the lowermost mantle from long-period seismology, this volume, 2007.
122. Revenaugh, J., and T.H. Jordan, Mantle layering from ScS reverberations, 4, The lower mantle and core-mantle boundary, J. Geophys. Res., 96, 19,811-19,824, 1991.
123. Revenaugh, J., and R. Meyer, Seismic evidence of partial melt within a possibly ubiquitous low velocity layer at the base of the mantle, Science, 277,670-673, 1997.
124. Ritsema, J., Evidence for shear wave anisotropy in the lowermost mantle beneath the Indian Ocean, Geophys. Res. Lett., 27,1041-1044, 2000.
125. Ritsema, J., and H.J. van Heijst, Seismic imaging of structural heterogeneity in Earth’s mantle: evidence for large-scale mantle flow, Science Progress, 83,243-259, 2000.
126. Ritsema, J., T. Lay, E.J. Garnero, and H. Benz, Seismic anisotropy in the lowermost mantle beneath the Pacific, Geophys. Res. Lett., 25,1229-1232, 1998.
127. Robertson, G.S., and J.H. Woodhouse, Ratio of relative S to P velocity heterogeneity in the lower mantle, J. Geophys. Res., 101, 20,041-20,052, 1996.
128. Rokosky, J.M., T. Lay, E.J. Garnero, and S.A. Russell, High-resolution investigation of shear wave anisotropy in D″ beneath the Cocos Plate, Geophys. Res. Lett., 31, L07605, doi:10.1029/2003GL018902, 2004.
129. Rokosky, J.M., T. Lay, and E.J. Garnero, Small-scale lateral variations in azimuthally anisotropic D″ structure beneath the Cocos Plate, Earth Planet. Sci. Lett., 248,396-410, 2006.
130. Romanowicz, B., Can we resolve 3D density heterogeneity in the lower mantle?, Geophys. Res. Lett., 28,1107-1110, 2001.
131. Rondenay, S., and K.M. Fischer, Constraints on localized core-mantle boundary structure from multi-channel, broadband SKS coda analysis, J. Geophys. Res., 108, 2537, doi_10.1029/2003JB002518, 2003.
132. Rost, S., and J. Revenaugh, Small-scale ultralow-velocity zone structure imaged by ScP, J. Geophys. Res., 108, 2056, doi:10.1029/2001JB001627, 2003.
133. Rost, S., E.J. Garnero, Q. Williams, and M. Manga, Seismic constraints on a possible plume root at the core-mantle boundary, Nature, 435,666-669, 2005.
134. Rost S., E.J. Garnero, and Q. Williams, Fine-scale ultralow-velocity zone structure from high-frequency seismic array data, J. Geophys. Res., 111, B09310, doi:10.1029/2005JB004088, 2006a.
135. Rost S., and E.J. Garnero, Detection of an ultralow velocity zone at the coremantle boundary using diffracted PKKP ab waves, J. Geophys. Res., 111, B07309, doi:10.1029/2005JB003850, 2006b.
136. Russell, S.A., T. Lay, and E.J. Garnero, Seismic evidence for small-scale dynamics in the lowermost mantle at the root of the Hawaiian hotspot, Nature, 396,255-258, 1998.
137. Russell, S.A., T. Lay, and E.J. Garnero, Small-scale lateral shear velocity and anisotropy heterogeneity near the core-mantle boundary beneath the central Pacific imaged using broadband ScS-waves, J. Geophys. Res., 104, 13,183-13,199, 1999.
138. Russell, S.A., C. Reasoner, T. Lay, and J. Revenaugh, Coexisting shear-and compressional-wave seismic velocity discontinuities beneath the central pacific, Geophys. Res. Lett., 28,2281-2284, 2001.
139. Sakai, T., T. Kondo, E. Ohtani, H. Terasaki, N. Endo, T. Kuba, T. Suzuki, and T. Kikegawa, Interaction between iron and post-perovskite at core-mantle boundary and core signature in plume source region, Geophys. Res. Lett., Vol. 33, L15317, doi:10.1029/2006GL026868, 2006.
140. Saltzer, R.L., R.D. van der Hilst, and H. Kárason, Comparing P and S wave heterogeneity in the mantle, Geophys. Res. Lett., 28,1335-1338, 2001.
141. Scherbaum, F., F. Krüger, and M. Weber, Double beam imaging: Mapping lower mantle heterogeneities using combinations of source and receiver arrays, J. Geophys. Res., 102,507-522, 1997.
142. Schimmel, M., and H. Paulssen, Steeply reflected ScSH precursors from the D″ region, J. Geophys. Res., 101, 16,077-16,088, 1996.
143. Schlittenhardt, J., J. Schweitzer, and G. Müller, Evidence against a discontinuity at the top of D″, Geophys. J.R. Astron. Soc., 81,295-306, 1985.
144. Serghiou, G., A. Zerr, and R. Boehler, (Mg,Fe)SiO3-perovskite stability under lower mantle conditions, Science, 280,2093-2095, 1998.
145. Shibutani, T., K. Hirahara, and M. Kato, P-wave velocity discontinuity in D″ layer beneath Western Pacific with J-Array records, in The Earth’s Central Part: Its Structure and Dynamics, edited by T. Yukutake, 1-11, 1995.
146. Shibutani, T., A. Tanaka, M. Kato, and K. Hirahara, A study of P-wave velocity discontinuity in D″ layer with J-array records: Preliminary results, J. Geomag. Geoelectr., 45,1275-1285, 1993.
147. Shieh, S.R., T.S. Duffy, A. Kubo, G. Shen, V.B. Prakapenka, N. Sata, K. Hirose, and Y. Ohishi, Equation of state of the postperovskite phase synthesized from a natural (Mg,Fe)SiO3 orthopyroxene, Proc. Natl. Acad. Sci. U.S.A., 103,3039-3043, 2006.
148. 3 perovskite to 2300-kilometer depth in the Earth’s mantle, Science, 293,2437-2440, 2001.
149. 3 perovskite to the core-mantle boundary, Geophys. Res. Lett., 31, L10603, doi:10.1029/2004GL019639, 2004.
150. Sidorin, I., M. Gurnis, and D.V. Helmberger, Evidence for a ubiquitous seismic discontinuity at the base of the mantle, Science, 286, 1326-1331, 1999a.
151. Sidorin, I., M. Gurnis, and D.V. Helmberger, Dynamics of a phase change at the base of the mantle consistent with seismological observations, J. Geophys. Res., 104, 15,005-15,023, 1999b.
152. Simmons, N.A., and S.P. Grand, Partial melting in the deepest mantle, Geophys. Res. Lett., 29, No. 11, 10.1029/2001Gl013716, 2002.
153. Simmons, N.A., A.M. Forte, and S.P. Grand, Thermochemical structure and dynamics of the African superplume, Geophys. Res. Lett., 34, L02301, doi:10.1029/2006GL028009, 2007.
154. Sinmyo, R., K. Hirose, H. St. C. O-Neill, and E. Okunishi, Ferric iron in Albearing post-perovskite, Geophys. Res. Lett., 33, L12S13, doi:10.1029/ 2006GL025858, 2006.
155. Spera, F.J., D.A. Yuen, and G. Giles, Tradeoffs in chemical and thermal variations in the post-perovskite phase transition: Mixed phase regions in the deep lower mantle? Phys. Earth Planet. Int., 159,234-246, 2006.
156. Stackhouse, S., and J.P. Brodholt, this volume, 2007. Stackhouse, S., J.P. Brodholt, and G.D. Price, High temperature elastic anisotropy of the perovskite and post-perovskite polymorphs of AL2O3, Geophys. Res. Lett., 32, L132305, doi:10.1029/2005GL0223163, 2005a.
157. 3, Earth Planet. Sci. Lett., 230, 1-10, 2005b.
158. Stackhouse, S., J.P. Brodholt, and G.D. Price, Elastic anisotropy of FeSiO3 end-members of the perovskite and post-perovskite phases, Geophys. Res. Lett., 33, L01304, doi:10.1029/2006GL023887, 2006.
159. Sturhahn, W., J.M. Jackson, and J.-F. Lin, The spin state of iron in minerals in Earth’s lower mantle, Geophys. Res. Lett., 32, L12307, doi:10.1029/2005GL022802, 2005.
160. Su, W.J., and A.M. Dziewonski, Simultaneous inversion for 3-D variations in shear and bulk velocity in the mantle, Phys. Earth Planet. Inter., 100,135-156, 1997.
161. Sun, D., A.T.-R. Song, and D. Helmberger, Complexity of D″ in the presence of slab-debris and phase changes, Geophys. Res. Lett., 33, L12S07, doi:10.1029/2005GL025384, 2006.
162. Sun, D., D. Helmberger, X. Song, and S.P. Grand, Predicting a global perovskite and post-perovskite phase boundary, this volume, 2007.
163. Sun, X., X. Song, S. Zheng, and D.V. Helmberger, Evidence for a chemicalthermal structure at base of mantle from sharp lateral P-wave variations beneath Central America, Proc. Nat. Acad. Sci., 104,26-30, 2007.
164. Sze, E.K.M., and R.D. van der Hilst, Core mantle boundary topography from short period PcP, PKP, and PKKP data, Phys. Earth Planet. Inter., 135,27-46, 2003.
165. 12 to 180 GPa: Effect of Al on post-perovskite phase transition, Geophys. Res. Lett., 32, L15306, doi: 10.1029/2005GL023309, 2005.
166. Tateno, S., K. Hirose, N. Sata, and Y. Ohishi, High-pressure behavior of MnGeO3 and CdGeO3 and the post-perovskite phase transition, Phys. Chem. Miner., 32,721-725, 2006.
167. Thomas, Ca., M. Weber, A. Agnon, and A. Hofstetter, A low velocity lamella in D″, Geophys. Res. Lett., 25,2885-2888, 1998.
168. Thomas, Ch., and J.M. Kendall, The lowermost mantle beneath northern Asia: (2) Evidence for D″ anisotropy, Geophys. J. Int., 151, 296-308, 2002.
169. Thomas, Ch., and M. Weber, P velocity heterogeneities in the lower mantle determined with the German Regional Seismic Network: Improvement of previous models and results of 2D modeling, Phys. Earth Planet. Inter., 101,105-117, 1997.
170. Thomas, Ch., T. Heesom, and J.-M. Kendall, Investigating the heterogeneity of the D″ region beneath the northern Pacific using a seismic array, J. Geophys. Res., 107, B11, 2274, doi:10.1029/2000JB000021, 2002.
171. Thomas, Ch., E.J. Garnero, and T. Lay, High resolution image of lowermost mantle structure under the Cocos Plate, J. Geophys. Res., 109, B08307, doi:10.1029/2004JB003013, 2004a.
172. Thomas, Ch., J.M. Kendall, and J. Lowman, Lower mantle seismic discontinuities and the thermal morphology of subducted slabs, Earth Planet. Sci. Lett., 225, 105-113, 2004b.
173. Thomas, Ch., J. Wookey, and M. Simpson, D″ anisotropy beneath Southeast Asia, Geophys. Res. Lett., 34, L04301, doi:10.1029/2006GL028965, 2007.
174. Thorne, M.S., and E.J. Garnero, Inferences on ultralow-velocity zone structure from a global analysis of SPdKS waves, J. Geophys. Res., 109, B08301, doi:10.1029/2004JB003010, 2004.
175. Tkalcic, H., and B. Romanowicz, Short scale heterogeneity in the lowermost mantle: insights from PcP-P and ScS-S data, Earth Planet. Sci. Lett., 201,57-68, 2001.
176. Toh, A., B. Romanowicz, Y. Capdeville, and N. Takeuchi, 3D effects of sharp boundaries at the borders of the African and Pacific Superplumes:observation and modeling, Earth and Planet Sci. Lett., 233, 237-253, 2005.
177. Trampert, J., F. Deschamps, J. Resovsky, and D. Yuen, Probabilistic tomography maps chemical heterogeneities throughout the lower mantle, Science, 306,853-856, 2004.
178. 3, Geophys. Res. Lett., 33, L12S04, doi10.1029/2006GL025706, 2006.
179. 3, Geophys. Res. Lett., 31, L14603, doi:10.1029/ 2004GL020278, 2004a.
180. 3 perovskite in the Earth’s lower mantle, Earth Planet. Sci. Lett., 224, 241-248, 2004b.
181. Usui, Y., Y. Hiramatsu, M. Furumoto, and M. Kanao, Thick and anisotropic D″ layer beneath Antarctic Ocean, Geophys. Res. Lett., 32, L13311, doi:10.1029/2005GL022622, 2005.
182. Valenzuela, R., and M.E. Wysession, Illuminating the base of the mantle with core-diffracted waves, in The Core-Mantle Boundary Region, edited by M. Gurnis, M.E Wysession, E. Knittle, and B.A. Buffet, American Geophysical Union, Washington, D.C., pp. 57-72, 1998.
183. van der Hilst, R.D., S. Widiyantoro, and E.R. Engdahl, Evidence for deep mantle circulation from global tomography, Nature, 386, 578-584, 1997.
184. van der Hilst, R.D., M.V. deHoop, P. Wang, S.-H. Shim, P. Ma, and L. Tenorio, Seismo-stratigraphy and thermal structure of Earth’s core-mantle boundary region, Science, in press, 2007.
185. Vasco, D.W., and L.R. Johnson, Whole Earth structure estimated from seismic arrival times, J. Geophys. Res., 103,2633-2671, 1998.
186. Vidale, J.E., and H.M. Benz, Seismological mapping of fine structure near the base of the Earth’s mantle, Nature, 361,529-532, 1993.
187. Vinnik, L.P., V. Farra, and B. Romanowicz,, Observational evidence for diffracted SV in the shadow of the Earth’s core, Geophys. Res. Lett., 16,519-522, 1989.
188. Vinnik, L.P., L. Breger, and B. Romanowicz, Anisotropic structure at the base of the Earth’s mantle, Nature, 393,564-567, 1998.
189. Vinnik, L.P., B. Romanowicz, Y. LeStunff, and L. Makeyeva, Seismic anisotropy in the D″ layer, Geophys. Res. Lett., 22,1657-1660, 1995.
190. Wang, P., M.V. de Hoop, R.D. van der Hilst, P. Ma, and L. Tenorio, Imaging of structure at and near the core mantle boundary using a generalized Radon transform: I-construction of image gathers, J. Geophys. Res., in press, 2006.
191. Wang, Y., and L. Wen, Mapping the geometry and geographic distribution of a very low velocity province at the base of the Earth’s mantle, J. Geophys. Res., 109, B10305, doi:10.1029/2003JB002674, 2004.
192. Wang, Y., and L. Wen, Geometry and P-and S-velocity structures of the “African Anomaly”, J. Geophys. Res., 111, B12304, doi:10.1029/2005 JB004241, 2006a.
193. Wang, Y., and L. Wen, Complex seismic anisotropy at the border of a very low velocity province at the base of the Earth’s mantle, J. Geophys. Res., in review, 2006b.
194. Weber, M., P-and S-wave reflections from anomalies in the lowermost mantle, Geophys. J. Int., 115, 183-210, 1993.
195. Weber, M., Lamellae in D″? An alternative model for lower mantle anomalies, Geophys. Res. Lett., 21,2531-2534, 1994.
196. Weber, M., and J.P. Davis, Evidence of a laterally variable lower mantle structure from P and S-waves, Geophys. J. Int., 102,231-255, 1990.
197. Weber, M., and M. Körnig, A search for anomalies in the lowermost mantle using seismic bulletins, Phys. Earth Planet. Int., 73,1-28, 1992.
198. Weber, M., J.P. Davis, C. Thomas, F. Krüger, F. Scherbaum, J. Schlittenhardt, and M. Körnig, The structure of the lowermost mantle as determined from using seismic arrays, in Seismic Modelling of the Earth’s Structure, Edited by E. Boschi, G. Ekström, and A. Morelli, pp. 399-442, Istit. Naz. Di Geophys., Rome, 1996.
199. Wen, L., Seismic evidence for a rapidly-varying compositional anomaly at the base of the Earth’s mantle beneath Indian ocean, Earth Planet. Sci. Lett., 194,83-95, 2001.
200. Wen, L., and D.V. Helmberger, Ultra-Low velocity zones near the core-mantle boundary from broadband PKP precursors, Science, 279,1701-1703, 1998.
201. Wen, L., P. Silver, D. James, and R. Kuehnel, Seismic evidence for a thermochemical boundary layer at the base of the Earth’s mantle, Earth Planet. Sci. Lett., 189,141-153, 2001.
202. 3, Phys. Rev. Lett., 70,3947-3950, 1993.
203. 3 postperovskite at D″ conditions, Proc. Natl. Acad. Sci. U. S. A., 103,543-546, 2006.
204. 3-perovskite: insights on the nature of the Earth’s lower mantle, Phys. Rev. Lett., 92, 018501-1-4, 2004.
205. Williams, Q., The temperature contrast across D″. In: The Core-Mantle Boundary Region, Gurnis, M., M.E. Wysession, E. Knittle, and B.A. Buffett (eds.), American Geophysical Union, Washington, D.C., pp 73-81, 1998.
206. Williams, Q., and E.J. Garnero, Seismic evidence for partial melt at the base of the Earth’s mantle, Science, 273,1528-1530, 1996.
207. Wookey, J., and J-M. Kendall, Seismic anisotropy of post-perovskite and the lowermost mantle, this volume, 2007.
208. Wookey, J., J.-M. Kendall, and G. Rümpker, Lowermost mantle anisotropy beneath the north Pacific from differential S-ScS splitting, Geophys. J. Int., 161, 829-838, 2005b.
209. Wookey, J., S. Stackhouse, J.-M. Kendall, J. Brodholt, and G.D. Price, Efficacy of the post-perovskite phase as an explanation for lowermostmantle seismic properties, Nature, 438, 1004-1007, 2005a.
210. Wright, C., Array studies of P phases and the structure of the D″ region of the mantle, J. Geophys. Res., 78,4965-4982, 1973.
211. Wright, C., and B.-Y. Kuo, The P wavespeed structure in the lowermost 700 km of the mantle below the central part of the Indian Ocean, Phys. Earth Planet. Inter., in press, 2007.
212. Wright, C., and J.A. Lyons, Seismology, dT/d and deep mantle convection, Geophys. J. R. Astron. Soc., 40,115-138, 1975.
213. Wright, C., and J.A. Lyons, The identification of radial velocity anomalies in the lower mantle using an interference method, Phys. Earth planet. Int., 18,27-33, 1979.
214. Wright, C., and J.A. Lyons, Further evidence for radial velocity anomalies in the lower mantle, Pure Appl. Geophys., 119,137-162, 1981.
215. Wright, C., K.J. Muirhead, and A.E. Dixon, The P-wave velocity structure near the base of the mantle, J. Geophys. Res., 90,623-634, 1985.
216. Wysession, M.E., T. Lay, J. Revenaugh, Q. Williams, E. Garnero, R. Jeanloz, and L. Kellogg, The D″ discontinuity and its implications, in The Core-Mantle Boundary Region, edited by M. Gurnis, M.E Wysession, E. Knittle, and B.A. Buffet, pp. 237-297, AGU, Washington, D.C, 1998.
217. Wysession, M.E., A. Langenhorst, M.J. Fouch, K.M. Fischer, G.I. Al-Eqabi, P.J. Shore, and T.J. Clark, Lateral variations in compressional/shear velocities at the base of the mantle, Science, 284,120-125, 1999.
218. Yamada, A., and I. Nakanishi, Short-wavelength lateral variation of a D″ Pwave reflector beneath the southwestern Pacific, Geophys. Res. Lett., 25,4545-4548, 1998.
219. Yamazaki, D., and S.-I. Karato, Fabric development in (Mg,O) during large strain shear deformation: implications for seismic anisotropy in Earth’s lower mantle, Phys. Earth. Planet. Int., 131,251-267, 2002.
220. Yamazaki, D., T. Yoshino, H. Ohfuji, J.-i. Ando, and A. Yoneda, Origin of seismic anisotropy in the D″ layer inferred from shear deformation experiments on post-perovskite phase, Earth Planet. Sci. Lett., in press, 2006.
221. Young, C.J., and T. Lay, Evidence for a shear velocity discontinuity in the lower mantle beneath India and the Indian Ocean, Phys. Earth Planet. Inter., 49,37-53, 1987.
222. Young, C.J., and T. Lay, Multiple phase analysis of the shear velocity structure in the D″ region beneath Alaska, J. Geophys. Res., 95, 17,385-17,402, 1990.
223. Zhao, D., Seismic structure and origin of hotspots and mantle plumes, Earth Planet. Sci. Lett., 192,251-265, 2001.
224. Zhao, D., Global tomographic images of mantle plumes and subducting slabs: insight into deep Earth dynamics, Physics of the Earth and Planetary Interiors, 146, 3-34, 2004.