Letter | Published:

High-resolution seismic constraints on flow dynamics in the oceanic asthenosphere

Nature volume 535, pages 538541 (28 July 2016) | Download Citation


Convective flow in the mantle and the motions of tectonic plates produce deformation of Earth’s interior, and the rock fabric produced by this deformation can be discerned using the anisotropy of the seismic wavespeed1,2,3. This deformation is commonly inferred close to lithospheric boundaries beneath the ocean in the uppermost mantle, including near seafloor-spreading centres as new plates are formed via corner flow4, and within a weak asthenosphere that lubricates large-scale plate-driven flow and accommodates smaller-scale convection5,6. Seismic models of oceanic upper mantle differ as to the relative importance of these deformation processes: seafloor-spreading fabric is very strong just beneath the crust–mantle boundary (the Mohorovičić discontinuity, or Moho) at relatively local scales7,8, but at the global and ocean-basin scales, oceanic lithosphere typically appears weakly anisotropic when compared to the asthenosphere9,10. Here we use Rayleigh waves, recorded across an ocean-bottom seismograph array in the central Pacific Ocean (the NoMelt Experiment), to provide unique localized constraints on seismic anisotropy within the oceanic lithosphere–asthenosphere system in the middle of a plate. We find that azimuthal anisotropy is strongest within the high-seismic-velocity lid, with the fast direction coincident with seafloor spreading. A minimum in the magnitude of azimuthal anisotropy occurs within the middle of the seismic low-velocity zone, and then increases with depth below the weakest portion of the asthenosphere. At no depth does the fast direction correlate with the apparent plate motion. Our results suggest that the highest strain deformation in the shallow oceanic mantle occurs during corner flow at the ridge axis, and via pressure-driven or buoyancy-driven flow within the asthenosphere. Shear associated with motion of the plate over the underlying asthenosphere, if present, is weak compared to these other processes.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    Seismic anisotropy of the uppermost mantle under oceans. Nature 203, 629–631 (1964)

  2. 2.

    The early structural evolution and anisotropy of the oceanic upper mantle. Geophys. J. Int. 43, 103–162 (1975)

  3. 3.

    Upper mantle low anisotropy channels below the Pacific Plate. Earth Planet. Sci. Lett. 202, 263–274 (2002)

  4. 4.

    & Seismic anisotropy in the upper mantle 2. Predictions for current plate boundary flow models. Geochem. Geophys. Geosyst. 3, 8602 (2002)

  5. 5.

    , , & Observational hints for a plume-fed, suboceanic asthenosphere and its role in mantle convection. J. Geophys. Res. 100, 12753–12767 (1995)

  6. 6.

    et al. Small-scale convection in a plume-fed low-viscosity layer beneath a moving plate. Geophys. J. Int. 194, 591–610 (2013)

  7. 7.

    , , & Anisotropy of the Pacific upper mantle. J. Geophys. Res. Solid Earth 74, 3095–3109 (1969)

  8. 8.

    , , , & Mantle deformation during slow seafloor spreading constrained by observations of seismic anisotropy in the western Atlantic. Earth Planet. Sci. Lett. 228, 255–265 (2004)

  9. 9.

    , , & Changes in seismic anisotropy shed light on the nature of the Gutenberg discontinuity. Science 343, 1237–1240 (2014)

  10. 10.

    et al. Oceanic lithosphere-asthenosphere boundary from surface wave dispersion data. J. Geophys. Res. Solid Earth 119, 1079–1093 (2014)

  11. 11.

    & Vectorial tomography—I. Theory. Geophys. J. Int. 94, 295–307 (1988)

  12. 12.

    & Trans-Pacific upper mantle shear velocity structure. J. Geophys. Res. 112, B08301 (2007)

  13. 13.

    & The anisotropic structure of the upper mantle in the Pacific. Geophys. J. Int. 96, 203–229 (1989)

  14. 14.

    et al. The electrical structure of the central Pacific upper mantle constrained by the NoMelt experiment. Geochem. Geophys. Geosyst. 16, 1115–1132 (2015)

  15. 15.

    & Grainsize-sensitive viscoelastic relaxation in olivine: towards a robust laboratory-based model for seismological application. Phys. Earth Planet. Inter. 183, 151–163 (2010)

  16. 16.

    & Water in the oceanic upper mantle: implications for rheology, melt extraction and the evolution of the lithosphere. Earth Planet. Sci. Lett. 144, 93–108 (1996)

  17. 17.

    , , & Structural mapping in the Oman ophiolites: mantle diapirism along an oceanic ridge. Tectonophysics 151, 27–56 (1988)

  18. 18.

    & An olivine fabric database: an overview of upper mantle fabrics and seismic anisotropy. Tectonophysics 296, 145–157 (1998)

  19. 19.

    & Anisotropy in the oceanic lithosphere — theory and observations from the Ngendei seismic refraction experiment in the south-west Pacific. Geophys. J. R. Astron. Soc. 80, 493–526 (1985)

  20. 20.

    , , & Azimuthal anisotropy of the Pacific region. Earth Planet. Sci. Lett. 250, 53–71 (2006)

  21. 21.

    & Seismic observations of large-scale deformation at the bottom of fast-moving plates. Earth Planet. Sci. Lett. 376, 165–177 (2013)

  22. 22.

    & Constraints on lithosphere net rotation and asthenospheric viscosity from global mantle flow models and seismic anisotropy. Geochem. Geophys. Geosyst. 11, Q05W05 (2010)

  23. 23.

    , , & Origin of azimuthal seismic anisotropy in oceanic plates and mantle. Earth Planet. Sci. Lett. 401, 236–250 (2014)

  24. 24.

    & The mantle flow field beneath western North America. Science 295, 1054–1057 (2002)

  25. 25.

    On the effect of temperature and strain-rate dependent viscosity on global mantle flow, net rotation, and plate-driving forces. Geophys. J. Int. 167, 943–957 (2006)

  26. 26.

    , & Constraints on asthenospheric flow from the depths of oceanic spreading centers: the East Pacific Rise and the Australian-Antarctic discordance. Geochem. Geophys. Geosyst. 10, Q09007 (2009)

  27. 27.

    , & Depth-dependent viscosity and mantle stress amplification: implications for the role of the asthenosphere in maintaining plate tectonics. Geophys. J. Int. 191, 30–41 (2012)

  28. 28.

    & Mantle convection and the thermal structure of the plates. J. Geophys. Res. Solid Earth 83, 4485–4496 (1978)

  29. 29.

    & Evidence for small-scale mantle convection from Seasat altimeter data. J. Geophys. Res. Solid Earth 91, 3507–3520 (1986)

  30. 30.

    & On the interaction of two scales of convection in the mantle. J. Geophys. Res. Solid Earth 80, 2529–2541 (1975)

  31. 31.

    , & Waveform tomography reveals channeled flow at the base of the oceanic asthenosphere. Science 342, 227–230 (2013)

  32. 32.

    , , , & New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure. Science 346, 65–67 (2014)

  33. 33.

    & No-net-rotation model of current plate velocities incorporating plate motion model NUVEL-1. Geophys. Res. Lett. 18, 2039–2042 (1991)

  34. 34.

    & Long-period seafloor seismology and deformation under ocean waves. Bull. Seismol. Soc. Am. 89, 1535–1542 (1999)

  35. 35.

    & Identifying and removing tilt noise from low-frequency (<0.1 Hz) seafloor vertical seismic data. Bull. Seismol. Soc. Am. 90, 952–963 (2000)

  36. 36.

    , & Removing noise from the vertical component records of ocean-bottom seismometers: results from year one of the Cascadia Initiative. Bull. Seismol. Soc. Am. 105, 300–313 (2015)

  37. 37.

    & Surface wave phase-velocity tomography based on multichannel cross-correlation. Geophys. J. Int. 201, 1383–1398 (2015)

  38. 38.

    , & Eikonal tomography: surface wave tomography by phase front tracking across a regional broad-band seismic array. Geophys. J. Int. 177, 1091–1110 (2009)

  39. 39.

    & The azimuthal dependence of Love and Rayleigh wave propagation in a slightly anisotropic medium. J. Geophys. Res. Solid Earth 78, 3321–3333 (1973)

  40. 40.

    & Waveform fitting of cross spectra to determine phase velocity using Aki’s formula. Bull. Seismol. Soc. Am. 105, 1619–1627 (2015)

  41. 41.

    Computer programs in seismology: an evolving tool for instruction and research. Seismol. Res. Lett. 84, 1081–1088 (2013)

  42. 42.

    & A simple method for inverting the azimuthal anisotropy of surface waves. J. Geophys. Res. Solid Earth 91, 511–520 (1986)

  43. 43.

    & Mapping tectonic deformation in the crust and upper mantle beneath Europe and the North Atlantic Ocean. Science 341, 871–875 (2013)

  44. 44.

    & Global upper mantle tomography of seismic velocities and anisotropies. J. Geophys. Res. 96, 20337–20351 (1991)

  45. 45.

    Observation and modeling of seismic background noise. Open-File Report No. 93-322 (US Department of Interior Geological Survey, 1993)

Download references


We thank the scientific party, captain, crews, and technical teams of RV Marcus G. Langseth and RV Melville for work that made this study possible. The OBS were provided and supported by Scripps Institution of Oceanography’s facility as part of the US Ocean Bottom Seismograph Instrument Pool (http://www.obsip.org). This work was funded by the US National Science Foundation. P.-Y.P.L. thanks the Institute of Earth Science, Academia Sinica, Taipei, Taiwan and Institute of Undersea Technology, National Sun Yat-sen University, Kaohsiung, Taiwan for support during completion of this work.

Author information

Author notes

    • Pei-Ying Patty Lin

    Present address: Taiwan Ocean Research Institute, National Applied Research Laboratories, Kaohsiung, Taiwan (P.-Y.P.L.).


  1. Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, USA

    • Pei-Ying Patty Lin
    • , James B. Gaherty
    •  & Ge Jin
  2. Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA

    • John A. Collins
    • , Daniel Lizarralde
    •  & Rob. L. Evans
  3. Geological Sciences Department, Brown University, Providence, Rhode Island, USA

    • Greg Hirth


  1. Search for Pei-Ying Patty Lin in:

  2. Search for James B. Gaherty in:

  3. Search for Ge Jin in:

  4. Search for John A. Collins in:

  5. Search for Daniel Lizarralde in:

  6. Search for Rob. L. Evans in:

  7. Search for Greg Hirth in:


P.-Y.P.L. and J.B.G. collaborated in developing the concept of this paper and writing the first draft. All authors contributed to the scientific discussion, including presentation of results, interpretation, and implications.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Pei-Ying Patty Lin.

Extended data

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.