High-resolution imaging of lowermost mantle structure under the Cocos plate

Journal of Geophysical Research: Solid Earth

Volumn 109, Issue 8, 2004, Pages

  Thomas, Christine ^a   Garnero, Edward J ^b   Lay, Thorne ^c  

^a UNIVERSITY OF LIVERPOOL   (United Kingdom)

^b ARIZONA STATE UNIVERSITY   (United States)

^c UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

Core mantle boundary; D"; Heterogeneity; Lower mantle; Shear waves

Indexed keywords

COCOS PLATE; CORE-MANTLE BOUNDARY; LOWER MANTLE; MANTLE STRUCTURE; SEISMIC VELOCITY; VELOCITY STRUCTURE;

EID: 7044286404     PISSN: 21699313     EISSN: 21699356     Source Type: Journal    
DOI: 10.1029/2004JB003013     Document Type: Article

References (51)

1. Anderson, D. L. (2001), Top-down tectonics?, Science, 293, 2016-2018.
2. Bilek, S. L., and T. Lay (1998), Lower mantle heterogeneity beneath Eurasia imaged by parametric migration of shear waves, Phys. Earth Planet. Inter., 108, 201-218.
3. Castle, J. C., and R. D. van der Hilst (2003a), Searching for seismic scattering off mantle interfaces between 800 km and 2000 km depth, J. Geophys. Res, 108(B2), 2095, doi:10.1029/2001JB000286.
4. Castle, J. C., and R. D. van der Hilst (2003b), Using ScP precursors to search for mantle structures beneath 1800 km depth, Geophys. Res. Lett., 30(8), 1422, doi:10.1029/2002GL016023.
5. Christensen, U. R., and A. W. Hofmann (1994), Segregation of subducted oceanic crust in the convecting mantle, J. Geophys. Res., 99, 19,867-19,884.
6. Davies, D., E. J. Kelly, and J. R. Filson (1971), Vespa process for analysis of seismic signals, Nature Phys. Sci., 232, 8-13.
7. Ding, X. M., and D. V. Helmberger (1997), Modeling D″ structure beneath Central America with broadband seismic data, Phys Earth Planet. Inter., 101, 245-270.
8. Fisher, J. L., M. E. Wysession, and K. M. Fischer (2003), Small-scale lateral variations in D″ attenuation and velocity structure, Geophys. Res. Lett., 30(8), 1435, doi:10.1029/2002GL016179.
9. Freybourger, M., S. Chevrot, F. Krüger, and U. Achauer (2001), A wave-form migration for the investigation of P wave structure at the top of D″ beneath northern Siberia, J. Geophys. Res., 106, 4129-4140.
10. Gaherty, J. B., and T. Lay (1992), Investigation of laterally heterogeneous shear velocity structure in D″ beneath Eurasia, J. Geophys. Res., 97, 417-435.
11. Garnero, E. J. (2000), Lower mantle heterogeneity, Annu. Rev. Earth Planet. Sci., 28, 509-537.
12. Garnero, E. J., and T. Lay (2003), D″ shear velocity heterogeneity, anisotropy and discontinuity structure beneath the Caribbean and Central America, Phys. Earth Planet. Inter., 140, 219-242.
13. Grand, S. P. (2002), Mantle shear wave tomography and the fate of subducted slabs, Philos. Trans R. Soc. London, Ser. A, 360, 2491-2575.
14. Grand, S. P., R. D. van der Hilst, and S. Widiyantoro (1997), Global seismic tomography: A snapshot of convection in the Earth, GSA Today, 7, 1 -7.
15. Kárason, H., and R. D. van der Hilst (2001), Tomographic imaging of the lowermost mantle with differential times of refracted and diffracted core phases PKP, Pdiff, J. Geophys. Res., 106, 6569-6587.
16. Kendall, J.-M., and C. Nangini (1996), Lateral variations in D″ below the Caribbean, Geophys. Res. Lett., 23, 399-402.
17. Kendall, J.-M., and P. M. Shearer (1994), Lateral variations in D″ thickness from long period shear wave data, J. Geophys. Res., 99, 1575-1590.
18. Kendall, J.-M. and P. G. Silver (1998), Investigating causes of D″ anisotropy, in The Core-Mantle Boundary Region, Geodyn. Ser., vol. 28, edited by M. Gurnis et al., pp. 97-118, AGU, Washington, D. C.
19. Kennett, B. L. N., E. R. Engdahl, and R. Buhland (1995), Constraints on seismic velocities in the Earth from travel-times, Geophys. J. Int., 122, 108-124.
20. Kito, T., and F. Krüger (2001), Heterogeneities in D″ beneath the southwestern Pacific inferred from scattered and reflected P waves, Geophys. Res. Lett., 28, 2545-2548.
21. Krüger, F., F. Scherbaum, M. Weber, and J. Schlittenhardt (1996), Analysis of asymmetric multipathing with a generalization of the double-beam method, Bull. Seismol. Soc. Am., 86, 737-749.
22. Lay, T., and E. J. Garnero (2004), Core-mantle boundary structures and processes, in Geophysical Monograph Series, edited by R. S. J. Sparks and C. J. Hawkesworth, AGU, Washington, D. C., in press.
23. Lay, T., and D. V. Helmberger (1983), A lower mantle S-wave triplication and the shear velocity structure of D″, Geophys. J. R. Astron. Soc., 75, 799-837.
24. Lay, T., and C. J. Young (1996), Imaging scattering structures in the lower mantle by migration of long-period S waves, J. Geophys. Res., 101, 20,023-20,040.
25. Lay, T., Q. Williams, E. J. Garnero, L. Kellogg, and M. E. Wysession (1998a), Seismic wave anisotropy in the D″ region and its implications, in The Core-Mantle Boundary Region, Geodyn. Ser, vol. 28, edited by M. Gurnis et al., pp. 299-318, AGU, Washington D. C.
26. Lay, T., Q. Williams, and E. J. Garnero (1998b), The core-mantle boundary layer and deep Earth dynamics, Nature, 392, 461-468.
27. Lay, T., E. J. Garnero, and Q. Williams (2004a), Partial melting in a thermochemical boundary layer at the base of the mantle, Phys. Earth Planet. Inter., in press.
28. Lay, T., E. J. Garnero, and S. A. Russell (2004b), Lateral variation of the D″ discontinuity beneath the Cocos plate, Geophys. Res. Lett., L15612, doi:10.1029/2004GL020300.
29. Lithgow-Bertelloni, C., and M. A. Richards (1998), The dynamics of Cenozoic and Mesozoic plate motions, Rev. Geophys., 316, 27-78.
30. Liu, X-F., J. Tromp, and A. M. Dziewonski (1998), Is there a first-order discontinuity in the lowermost mantle?, Earth Planet. Sci. Lett., 160, 343-351.
31. Masters, G., H. Bolton, A. M. Dziewonski, and G. Laske (2000), 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, Geophys. Monogr. Ser., vol. 117, edited by S. Karato et al., pp. 63-87, AGU, Washington, D. C.
32. Mégnin, C., and B. Romanowicz (2000), The 3D shear velocity structure of the mantle from the inversion of body, surface and higher mode waveforms, Geophys. J. Int., 143, 709-728.
33. Moore, M. M., E. J. Garnero, T. Lay, and Q. Williams (2004), Shear wave splitting and waveform complexity for lowermost mantle structures with low-velocity lamellae and transverse isotropy, J. Geophys. Res., 109, B02319, doi:10.1029/2003JB002546.
34. Mori, J., and D. V. Helmberger (1995), Localized boundary layer below the mid-Pacific velocity anomaly identified from a PcP precursor, J. Geophys. Res., 100, 20,359-20,365.
35. Müller, G. (1985), The reflectivity method: A tutorial, J. Geophys., 58, 153-174.
36. Reasoner, C., and J. Revenaugh (1999), Short-period P wave constraints on D″ reflectivity, J. Geophys. Res., 104, 955-961.
37. Rokosky, J., T. Lay, E. J. Garnero, and S. A. Russell (2004), High-resolution investigation of shear wave anisotropy in D″ beneath the Cocos plate, Geophys. Res. Lett., 31, L07605, doi:10.1029/2003GL018902.
38. Rost, S., and J. Revenaugh (2003), Small-scale ultralow-velocity zone structure imaged by ScP, J. Geophys. Res., 108(B1), 2056, doi:10.1029/2001JB001627.
39. Rost, S., and C. Thomas (2002), Array seismology: Methods and application, Rev. Geophys., 40(3), 1008, doi:0.1029/2000RG000100.
40. Scherbaum, F., F. Krüger, and M. Weber (1997), Double beam imaging: Mapping lower mantle heterogeneities using combinations of source and receiver arrays, J. Geophys. Res., 102, 507-522.
41. Sidorin, I., M. Gurnis, and D. V. Helmberger (1999), Dynamics of a phase change at the base of the mantle consistent with seismological observations, J. Geophys. Res., 104, 15,005-15,023.
42. Tan, E., M. Gurnis, and L. Han (2002), Slabs in the lower mantle and their modulation of plume formation, Geochem. Geophys. Geosyst., 3 11), 1067, doi:10.1029/2001GC000238.
43. Thomas, C., M. Weber, A. Agnon, and A. Hofstetter (1998), A low-velocity lamella in D″, Geophys. Res. Lett., 25, 2885-2888.
44. Thomas, C., M. Weber, C. Wicks, and F. Scherbaum (1999), Small seatterers in the lower mantle observed at German broadband arrays, J. Geophys. Res., 104, 15,073-15,088.
45. Thomas, C., J.-M. Kendall, and J. P. Lowman (2004), Lower-mantle seismic discontinuities and the thermal morphology of subducted slabs, Earth Planet. Sci. Lett., in press.
46. Weber, M. (1993), P- and S-wave reflections from anomalies in the lower mantle, Geophys. J. Int., 115, 183-210.
47. Weber, M., and J. P. Davis (1990), Evidence of a laterally variable lower mantle structure from P- and S-waves, Geophys. J. Int., 102, 231-255.
48. Wessel, P., and W. H. F. Smith (1991), Free software helps map and display data, Eos Trans. AGU, 72(441), 445-446.
49. Wysession, M. E., T. Lay, J. Revenaugh, Q. Williams, E. J. Garnero, R. Jeanloz, and L. H. Kellogg (1998), The D″ discontinuity and its implications, in The Core-Mantle Boundary Region, Geodyn. Ser., vol. 28, edited by M. Gurnis et al., pp. 273-297, AGU, Washington D. C.
50. Wysession, M. E., K. M. Fischer, G. I. Al-Eqabi, P. J. Shore, and I. Gurari (2001), Using MOMA broadband array ScS-S data to image smaller-scale structures at the base of the mantle, Geophys. Res. Lett., 28, 867-870.
51. Zhang, J., and T. Lay (1984), Investigation of a lower mantle shear-wave triplication using a broadband array, Geophys. Res. Lett, 11, 620-623.