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Array Triplication Data Constraining Seismic Structure and Composition in the Mantle

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Abstract

Seismic data recorded in the upper mantle triplication distance range between 10° and 30° are generated by wave propagation through complex upper mantle structure. They can be used to place constraints on seismic velocity structures in the upper mantle, key seismic features near the major discontinuities, and anisotropic structure varying with depth. In this paper, we review wave propagation of the upper mantle triplicated phases, how different key seismic features can be studied using upper mantle triplicated data, and the importance of those seismic features to the understanding of mantle temperature and composition. We present two examples of using array triplicated phases to constrain upper mantle velocity structures and detailed features of a certain discontinuity, with one for a shallow event and the other for deep events. For the shallow event, we present examples of how the array triplication data can be used to constrain several key properties of the upper mantle: existence of a lithospheric lid, existence of a low velocity zone beneath the lithospheric lid, and P/S velocity ratio as a function of depth. For deep events, we show examples of how array triplication data can be used to constrain the detailed structures of a certain discontinuity: velocity gradients above and below the discontinuity, velocity jumps across the discontinuity and depth extents of different velocity gradients. We discuss challenges of the upper mantle triplication study, its connection to other approaches, and its potential for further studying some other important features of the mantle: the existence of double 660-km discontinuities, existence of low-velocity channels near major discontinuities and anisotropy varying with depth.

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References

  1. An Y, Gu YJ, Sacchi M (2007) Imaging mantle discontinuities using least-squares radon transform. J Geophys Res 112. doi:10.1029/2007JB005009

  2. Bercovici D, Karato S (2003) Whole-mantle convection and the transition-zone water filter. Nature 425:39–44

  3. Brudzinski MR, Chen WP (2000) Variations in P wave speeds and outboard earthquakes: evidence for a petrologic anomaly in the mantle transition zone. J Geophys Res 105:21661–21682

  4. Brudzinski MR, Chen WP (2003) A petrologic anomaly accompanying outboard earthquakes beneath Fiji-Tonga: corresponding evidence from broadband P and S waveforms. J Geophys Res 108. doi:10.1029/2002JB002012

  5. Brudzinski MR, Chen WP, Nowack RL, Huang BS (1997) Variations of P wave speeds in the mantle transition zone beneath the northern Philippine Sea. J Geophys Res 102:11815–11827

  6. Burdick LJ, Helmberger DV (1978) The upper mantle P velocity structure of the Western United States. J Geophys Res 83:1699–1712

  7. Chambers K, Deuss A, Woodhouse JH (2005) Reflectivity of the 410-km discontinuity from PP and SS precursors. J Geophys Res 110. doi:10.1029/2004JB003345

  8. Chen WP, Brudzinski MR (2003) Seismic anisotropy in the mantle transition zone beneath Fiji-Tonga. Geophys Res Lett 30:1682–1696

  9. Chen WP, Tseng TL (2007) Small 660-km seismic discontinuity beneath Tibet implies resting ground for detached lithosphere. J Geophys Res 112. doi:10.1029/2006JB004607

  10. Chen L, Wen L, Zheng T (2005) A wave equation migration method for receiver function imaging: 1.theory. J Geophys Res 110. doi:10.1029/2005JB003665

  11. Cummins PR, Kennett BLN, Bowman JR, Bostock MG (1992) The 520 km discontinuity? Bull Seism Soc Am 82:323–336

  12. Deuss A, Redfern SAT, Chambers K, Woodhouse JH (2006) The nature of the 660-kilometer discontinuity in Earth’s mantle from global seismic observations of PP precursors. Science 311:198–201

  13. Dziewonski AM, Anderson DL (1981) Preliminary reference Earth model. Phys Earth Planet Int 25:297–356

  14. Given JW, Helmberger DV (1980) Upper mantle structure of northwestern Eurasia. J Geophys Res 85:7183–7194

  15. Grand SP, Helmberger DV (1984a) Upper mantle shear structure of North America. Geophys J R Astron Soc 76:399–438

  16. Grand SP, Helmberger DV (1984b) Upper mantle shear structure beneath the Northwest Atlantic Ocean. J Geophys Res 89:11465–11475

  17. Gu YJ, Dziwonski AM (2002) Global variability of transition zone thickness. J Geophys Res 107. doi:10.1029/2001JB000489

  18. Gu YJ, Dziwonski AM, Ekstrom G (2003) Simultaneous inversion for mantle shear velocity and topography of transition zone discontinuities. Geophys J Int 154:559–583

  19. Helmberger DV, Wiggins RA (1971) Upper mantle structure of Midwestern United States. J Geophys Res 76:3229–3245

  20. Houard S, Nataf HC (1993) Laterally varying reflector at the top of D’’ beneath northern Siberia. Geophys J Int 115:168–182

  21. Jordan TH (1978) Composition and development of the continental tectosphere. Nature 274:544–548

  22. LeFevre LV, Helmberger DV (1989) Upper mantle P velocity structure of the Canadian Shield. J Geophys Res 94:17749–17765

  23. Li L, Weidner DJ (2008) Effect of phase transitions on compressional-wave velocities in the Earth’s mantle. Nature 454:984–986

  24. Melbourne T, Helmberger DV (1998) Fine structure of the 410-km discontinuity. J Geophys Res 103:10091–10102

  25. Neele F (1996) Sharp 400-km discontinuity from short-period P reflections. Geophys Res Lett 23:419–422

  26. Niu F, Kawakatsu H (1996) Complex structure of mantle discontinuities at the tip of the subducting slab beneath Northeast China—a preliminary investigation of broadband receiver functions. J Phys Earth 44:701–711

  27. Nyblade AA, Robinson SW (1994) The African superswell. Geophys Res Lett 21:765–768

  28. Obayashi M, Sugioka H, Yoshimitsu J, Fukao Y (2006) High temperature anomalies oceanward of subducting slabs at the 410-km discontinuity. Earth Planet Sci Lett 243:149–158

  29. Shearer PM (1991) Constraints on upper mantle discontinuities from observations of long-period reflected and converted phases. J Geophys Res 96:18147–18182

  30. Shearer PM, Flanagan MP (1999) Seismic velocity and density jumps across the 410- and 660-kilometer discontinuities. Science 285:1545–1548

  31. Shen Y, Solomon SC, Bjarnason IT, Purdy GM (1996) Hot mantle transition zone beneath Iceland and the adjacent Mid-Atlantic Ridge inferred from P-to-S conversions at the 410- and 660-km discontinuities. Geophys Res Lett 23:3527–3530

  32. Simon RE, Wright C, Kgaswane EM, Kwadiba MTO (2002) The P wavespeed structure below and around the Kaapvaal craton to depth of 800 km, from travel times and waveforms of local and regional earthquakes and mining-induced tremors. Geophys J Int 151:132–145

  33. Simon RE, Wright C, Kwadiba MTO, Kgaswane EM (2003) Mantle structure and composition to 800-km depth beneath southern Africa and surrounding oceans from broadband body waves. Lithos 71:353–367

  34. Song TA, Helmberger DV (2006) Low velocity zone atop the transition zone in the western US from S waveform triplication. In: Jacobsen SD, van der Lee S (eds) Earth’s deep water cycle. American Geophysical Union, Washington, DC

  35. Song TA, Helmberger DV, Grand SP (2004) Low-velocity zone atop the 410-km seismic discontinuity in the northwestern United States. Nature 427:530–533

  36. Tseng TL, Chen WP (2004) Contrasts in seismic wave speeds and density across the 660-km discontinuity beneath Philippine and the Japan Seas. J Geophys Res 109. doi:10.1029/2003JB002613

  37. Tseng TL, Chen WP (2008) Discordant contrasts of P- and S-wave speeds across the 660-km discontinuity beneath Tibet: a case for hydrous remnant of sub-continental lithosphere. Earth Planet Sci Lett 268:450–462

  38. Walck MC (1984) The P-wave upper mantle structure beneath an active spreading center: the Gulf of California. Geophys J R Astron Soc 76:697–723

  39. Wang Y, Wen L (2007) Geometry and P and S velocity structure of the “Africa anomaly”. J Geophys Res 112. doi:10.1029/2006JB004483

  40. Wang Y, Wen L, Weidner DJ, He Y (2006) SH velocity and compositional models near the 660-km discontinuity beneath South America and northeast Asia. J Geophys Res 111. doi:10.1029/2005JB003849

  41. Wang Y, Wen L, Weidner DJ (2008) Upper mantle SH- and P-velocity structures and compositional models beneath southern Africa. Earth Planet Sci Lett 267:596–608

  42. Wiggins RA, Helmberger DV (1973) Upper mantle structure of the Western United States. J Geophys Res 78:1870–1880

  43. Zhang J (1994) Melting experiments on anhydrous peridotite KLB-1 from 5.0 to 22.5 Gpa. J Geophys Res 99:17729–17742

  44. Zhao MC, Langston CA, Nyblade AA, Owens TJ (1999) Upper mantle velocity structure beneath southern Africa from modeling regional seismic data. J Geophys Res 104:47830–47894

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Acknowledgments

We thank the principal investigators of the Kaapvaal Seismic Array, the BANJO and BLSP for their efforts in collecting the data and the New Chinese Digital Seismic Network (NCDSN) for providing the data, and Sue Webb and Matthew Fouch for the digitized geological boundaries in Africa. This work is supported by an NSF grant #0439978.

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Correspondence to Yi Wang.

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Wang, Y., Wen, L. & Weidner, D. Array Triplication Data Constraining Seismic Structure and Composition in the Mantle. Surv Geophys 30, 355–376 (2009) doi:10.1007/s10712-009-9073-3

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Keywords

  • Triplication data
  • Upper mantle
  • Velocity structures
  • Upper mantle discontinuity
  • Mantle composition