Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Distinct slab interfaces imaged within the mantle transition zone

Abstract

Oceanic lithosphere descends into Earth’s mantle at subduction zones and drives material exchange between Earth’s surface and its deep interior. The subduction process creates chemical and thermal heterogeneities in the mantle, with the strongest gradients located at the interfaces between subducted slabs and the surrounding mantle. Seismic imaging of slab interfaces is key to understanding slab compositional layering, deep-water cycling and melting, yet the existence of slab interfaces below 200 km remains unconfirmed. Here, we observe two sharp and slightly dipping seismic discontinuities within the mantle transition zone beneath the western Pacific subduction zone that coincide spatially with the upper and lower bounds of the high-velocity slab. Based on a multi-frequency receiver function waveform modelling, we found the upper discontinuity to be consistent with the Mohorovičić discontinuity of the subducted oceanic lithosphere in the mantle transition zone. The lower discontinuity could be caused by partial melting of sub-slab asthenosphere under hydrous conditions in the seaward portion of the slab. Our observations show distinct slab–mantle boundaries at depths between 410 and 660 km, deeper than previously observed, suggesting a compositionally layered slab and high water contents beneath the slab.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Map of the subduction region in northeast China.
Fig. 2: Slab interfaces imaged at MTZ depths are consistent with slab geometry inferred from seismicity and full-waveform tomography images.
Fig. 3: Velocity perturbations across phases X1 and X2 inferred from multi-frequency waveform modelling are large, around 4–6%.
Fig. 4: Observations show that the slab interfaces can persist to MTZ depths.

Data availability

Seismic data from CSN were provided by the Data Management Center of China National Seismic Network at Institute of Geophysics, China Earthquake Administration (https://doi.org/10.11998/SeisDmc/SN, http://www.seisdmc.ac.cn, registration is required to download the data, in Chinese). The NECESSArray data were downloaded through the Incorporated Research Institutions for Seismology (https://doi.org/10.7914/SN/YP_2009). Waveforms of the NECsaids data are deposited in the Seismic Array Laboratory, Institute of Geology and Geophysics, Chinese Academy of Sciences (https://doi.org/10.12129/IGGSL.Data.Observation, http://www.seislab.cn) and can be downloaded via ftp://159.226.119.161/data/NECsaids/RF2020. The Seismic Array Laboratory will make the NECsaids Array data publicly available from October 2021 (three years after the completion of the NECsaids project). In addition, the raw multi-frequency (with Gaussian low-pass filters of 0.5, 0.75, 1.0 or 1.5) receiver function waveform data (2.7Gb) obtained in this study can be downloaded either from https://doi.org/10.12197/2020GA012 (World Data System for Geophysics; http://www.geophys.ac.cn) or from ftp://159.226.119.161/data/NECsaids/RF2020.

Code availability

The RF CCP stacking code was downloaded from http://www.eas.slu.edu/People/LZhu/home.html. The other codes used in this paper are available upon request from the corresponding authors.

References

  1. 1.

    Hacker, B. R., Abers, G. A. & Peacock, S. M. Subduction factory 1. Theoretical mineralogy, densities, seismic wave speeds, and H2O contents. J. Geophys. Res. Solid Earth 108, 133–137 (2003).

    Google Scholar 

  2. 2.

    Fukao, Y. & Obayashi, M. Subducted slabs stagnant above, penetrating through, and trapped below the 660 km discontinuity. J. Geophys. Res. Solid Earth 118, 5920–5938 (2013).

    Google Scholar 

  3. 3.

    Huang, J. L. & Zhao, D. P. High-resolution mantle tomography of China and surrounding regions. J. Geophys. Res. Solid Earth 111, B09305 (2006).

    Google Scholar 

  4. 4.

    Tao, K., Grand, S. P. & Niu, F. Seismic structure of the upper mantle beneath eastern Asia from full waveform seismic tomography. Geochem. Geophys. Geosyst. 19, 2732–2763 (2018).

    Google Scholar 

  5. 5.

    Kawakatsu, H. et al. Seismic evidence for sharp lithosphere-asthenosphere boundaries of oceanic plates. Science 324, 499–502 (2009).

    Google Scholar 

  6. 6.

    Kawakatsu, H. & Watada, S. Seismic evidence for deep-water transportation in the mantle. Science 316, 1468–1471 (2007).

    Google Scholar 

  7. 7.

    Stern, T. A. et al. A seismic reflection image for the base of a tectonic plate. Nature 518, 85–88 (2015).

    Google Scholar 

  8. 8.

    Tonegawa, T. et al. Water flow to the mantle transition zone inferred from a receiver function image of the Pacific slab. Earth Planet. Sci. Lett. 274, 346–354 (2008).

    Google Scholar 

  9. 9.

    Iwamori, H. Transportation of H2O beneath the Japan arcs and its implications for global water circulation. Chem. Geol. 239, 182–198 (2007).

    Google Scholar 

  10. 10.

    Yang, J. & Faccenda, M. Intraplate volcanism originating from upwelling hydrous mantle transition zone. Nature 579, 88–91 (2020).

    Google Scholar 

  11. 11.

    Ohtani, E. Water in the mantle. Elements 1, 25–30 (2005).

    Google Scholar 

  12. 12.

    Kawakatsu, H. & Utada, H. Seismic and electrical signatures of the lithosphere–asthenosphere system of the normal oceanic mantle. Annu. Rev. Earth Planet. Sci. 45, 139–167 (2017).

    Google Scholar 

  13. 13.

    Langston, C. A. Structure under Mount Rainier, Washington, inferred from teleseismic body waves. J. Geophys. Res. 84, 4749–4762 (1979).

    Google Scholar 

  14. 14.

    Zhu, L. P. Crustal structure across the San Andreas Fault, southern California from teleseismic converted waves. Earth Planet. Sci. Lett. 179, 183–190 (2000).

    Google Scholar 

  15. 15.

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

    Google Scholar 

  16. 16.

    Engdahl, E. R. et al. ISC‐EHB 1964–2016, an improved data set for studies of Earth structure and global seismicity. Earth Space Sci. 7, e2019EA000897 (2020).

    Google Scholar 

  17. 17.

    Tauzin, B., Debayle, E. & Wittlinger, G. Seismic evidence for a global low-velocity layer within the Earth’s upper mantle. Nat. Geosci. 3, 718–721 (2010).

    Google Scholar 

  18. 18.

    van der Meijde, M., Marone, F., Giardini, D. & van der Lee, S. Seismic evidence for water deep in Earth’s upper mantle. Science 300, 1556–1558 (2003).

    Google Scholar 

  19. 19.

    Bostock, M. G. Seismic waves converted from velocity gradient anomalies in the Earth’s upper mantle. Geophys. J. Int. 138, 747–756 (1999).

    Google Scholar 

  20. 20.

    Shearer, P. M. Seismic imaging of upper-mantle structure with new evidence for a 520-km discontinuity. Nature 344, 121–126 (1990).

    Google Scholar 

  21. 21.

    Deuss, A. & Woodhouse, J. Seismic observations of splitting of the mid-transition zone discontinuity in Earth’s mantle. Science 294, 354–357 (2001).

    Google Scholar 

  22. 22.

    Saikia, A., Frost, D. J. & Rubie, D. C. Splitting of the 520-kilometer seismic discontinuity and chemical heterogeneity in the mantle. Science 319, 1515–1518 (2008).

    Google Scholar 

  23. 23.

    Sinogeikin, S. V., Bass, J. D. & Katsura, T. Single-crystal elasticity of ringwoodite to high pressures and high temperatures: implications for 520 km seismic discontinuity. Phys. Earth Planet. Inter. 136, 41–66 (2003).

    Google Scholar 

  24. 24.

    Valdez, M. N., Wu, Z. Q., Yu, Y. G., Revenaugh, J. & Wentzcovitch, R. M. Thermoelastic properties of ringwoodite (Fex,Mg1-x)2SiO4: its relationship to the 520 km seismic discontinuity. Earth Planet. Sci. Lett. 351, 115–122 (2012).

    Google Scholar 

  25. 25.

    Tauzin, B., Kim, S. & Afonso, J. C. Multiple phase changes in the mantle transition zone beneath northeast Asia: constraints from teleseismic reflected and converted body waves. J. Geophys. Res. Solid Earth 123, 6636–6657 (2018).

    Google Scholar 

  26. 26.

    Xu, W. B., Lithgow-Bertelloni, C., Stixrude, L. & Ritsema, J. The effect of bulk composition and temperature on mantle seismic structure. Earth Planet. Sci. Lett. 275, 70–79 (2008).

    Google Scholar 

  27. 27.

    Tauzin, B. & Ricard, Y. Seismically deduced thermodynamics phase diagrams for the mantle transition zone. Earth Planet. Sci. Lett. 401, 337–346 (2014).

    Google Scholar 

  28. 28.

    Yang, J. et al. Slab-triggered wet upwellings produce large volumes of melt: insights into the destruction of the North China Craton. Tectonophysics 746, 266–279 (2018).

    Google Scholar 

  29. 29.

    Irifune, T. et al. Sound velocities of majorite garnet and the composition of the mantle transition region. Nature 451, 814–817 (2008).

    Google Scholar 

  30. 30.

    Li, D., Helmberger, D., Clayton, R. W. & Sun, D. Global synthetic seismograms using a 2-D finite-difference method. Geophys. J. Int. 197, 1166–1183 (2014).

    Google Scholar 

  31. 31.

    Ringwood, A. E. & Irifune, T. Nature of the 650-km seismic discontinuity: implications for mantle dynamics and differentiation. Nature 331, 131–136 (1988).

    Google Scholar 

  32. 32.

    Gréaux, S. et al. Sound velocity of CaSiO3 perovskite suggests the presence of basaltic crust in the Earth’s lower mantle. Nature 565, 218–221 (2019).

    Google Scholar 

  33. 33.

    Shen, Y. & Blum, J. Seismic evidence for accumulated oceanic crust above the 660-km discontinuity beneath southern Africa. Geophys. Res. Lett. 30, 1925 (2003).

    Google Scholar 

  34. 34.

    Eagar, K. C., Fouch, M. J. & James, D. E. Receiver function imaging of upper mantle complexity beneath the Pacific Northwest, United States. Earth Planet. Sci. Lett. 297, 141–153 (2010).

    Google Scholar 

  35. 35.

    Tauzin, B., Kim, S. & Kennett, B. L. N. Pervasive seismic low-velocity zones within stagnant plates in the mantle transition zone: thermal or compositional origin? Earth Planet. Sci. Lett. 477, 1–13 (2017).

    Google Scholar 

  36. 36.

    Shen, X., Yuan, X. & Li, X. A ubiquitous low-velocity layer at the base of the mantle transition zone. Geophys. Res. Lett. 41, 836–842 (2014).

    Google Scholar 

  37. 37.

    Ganguly, J., Freed, A. M. & Saxena, S. K. Density profiles of oceanic slabs and surrounding mantle: integrated thermodynamic and thermal modeling, and implications for the fate of slabs at the 660km discontinuity. Phys. Earth Planet. Inter. 172, 257–267 (2009).

    Google Scholar 

  38. 38.

    Kono, Y., Irifune, T., Ohfuji, H., Higo, Y. & Funakoshi, K. Sound velocities of MORB and absence of a basaltic layer in the mantle transition region. Geophys. Res. Lett. 39, L24306 (2012).

    Google Scholar 

  39. 39.

    Hawley, W. B., Allen, R. M. & Richards, M. A. Tomography reveals buoyant asthenosphere accumulating beneath the Juan de Fuca plate. Science 353, 1406–1408 (2016).

    Google Scholar 

  40. 40.

    Phipps Morgan, J., Hasenclever, J., Hort, M., Rüpke, L. & Parmentier, E. M. On subducting slab entrainment of buoyant asthenosphere. Terra Nova 19, 167–173 (2007).

    Google Scholar 

  41. 41.

    Tang, Y. et al. Changbaishan volcanism in northeast China linked to subduction-induced mantle upwelling. Nat. Geosci. 7, 470–475 (2014).

    Google Scholar 

  42. 42.

    Liu, L. & Zhou, Q. Deep recycling of oceanic asthenosphere material during subduction. Geophys. Res. Lett. 42, 2204–2211 (2015).

    Google Scholar 

  43. 43.

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

    Google Scholar 

  44. 44.

    Kelbert, A., Schultz, A. & Egbert, G. Global electromagnetic induction constraints on transition-zone water content variations. Nature 460, 1003–1006 (2009).

    Google Scholar 

  45. 45.

    Li, J., Wang, X., Wang, X. J. & Yuen, D. A. P and SH velocity structure in the upper mantle beneath Northeast China: evidence for a stagnant slab in hydrous mantle transition zone. Earth Planet. Sci. Lett. 367, 71–81 (2013).

    Google Scholar 

  46. 46.

    Fei, H. & Katsura, T. High water solubility of ringwoodite at mantle transition zone temperature. Earth Planet. Sci. Lett. https://doi.org/10.1016/j.epsl.2019.115987 (2019).

  47. 47.

    Hirose, K. Phase transitions in pyrolitic mantle around 670-km depth: implications for upwelling of plumes from the lower mantle. J. Geophys. Res. Solid Earth 107, 2078 (2002).

    Google Scholar 

  48. 48.

    Litasov, K. D. & Ohtani, E. in Advances in High-Pressure Mineralogy 115–156 (GSA, 2007).

  49. 49.

    Kennett, B. L. N. & Engdahl, E. R. Traveltimes for global earthquake location and phase identification. Geophys. J. Int. 105, 429–465 (1991).

    Google Scholar 

  50. 50.

    Dziewonski, A. M. & Anderson, D. L. Preliminary reference Earth model. Phys. Earth Planet. Inter. 25, 297–356 (1981).

    Google Scholar 

  51. 51.

    Ni, J. Collaborative Research: Northeast China Extended Seismic Array: Deep Subduction, Mantle Dynamics and Lithospheric Evolution Beneath Northeast China (International Federation of Digital Seismograph Networks, 2009); https://doi.org/10.7914/SN/YP_2009

  52. 52.

    Waveform Data of China National Seismic Network (in Chinese) (Institute of Geophysics, Data Management Centre of China National Seismic Network, 2007); https://doi.org/10.11998/SeisDmc/SN

  53. 53.

    Niu, F. & Li, J. Component azimuths of the CEArray stations estimated from P-wave particle motion. Earthq. Sci. 24, 3–13 (2011).

    Google Scholar 

  54. 54.

    Wang, X., Chen, Q. F., Li, J. & Wei, S. J. Seismic sensor misorientation measurement using P-wave particle motion: an application to the NECsaids array. Seismol. Res. Lett. 84, 901–911 (2016).

    Google Scholar 

  55. 55.

    Ligorría, J. P. & Ammon, C. J. Iterative deconvolution and receiver-function estimation. Bull. Seismol. Soc. Am. 89, 1395–1400 (1999).

    Google Scholar 

  56. 56.

    Ammon, C. J. The isolation of receiver effects from teleseismic P waveforms. Bull. Seismol. Soc. Am. 81, 2504–2510 (1991).

    Google Scholar 

  57. 57.

    Efron, B. & Tibshirani, R. Statistical data analysis in the computer age. Science 253, 390–395 (1991).

    Google Scholar 

  58. 58.

    Schulze, K. et al. Seismically invisible water in Earth’s transition zone? Earth Planet. Sci. Lett. 498, 9–16 (2018).

    Google Scholar 

  59. 59.

    Buchen, J. et al. High-pressure single-crystal elasticity of wadsleyite and the seismic signature of water in the shallow transition zone. Earth Planet. Sci. Lett. 498, 77–87 (2018).

    Google Scholar 

  60. 60.

    Li, C. & van der Hilst, R. D. Structure of the upper mantle and transition zone beneath Southeast Asia from traveltime tomography. J. Geophys. Res. Solid Earth 115, B07308 (2010).

    Google Scholar 

Download references

Acknowledgements

We thank L. Chen, H. Kawakatsu, T.-R. A. Song, S. P. Grand, J. Yang and J. Hu for numerous discussions during this work. We thank all the people who installed and service the NECsaids array. We also thank V. Lambert and P. Adamek for linguistic suggestions. This study was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (grant number XDB18000000) and the National Natural Science Foundation of China (grant numbers 91958209, 41974057, 41130316 and 41630209). J.B. was supported by the National Science Foundation’s Collaborative Study of Earth’s Deep Interior (EAR-1161046 and EAR-2009935).

Author information

Affiliations

Authors

Contributions

X.W. and Q-F.C. designed the research. X.W. conducted the seismic analysis. X.W., Q-F.C., F.N., J.B. and L.L. contributed to the interpretation of seismic observations. X.W. wrote the manuscript, and all co-authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Qi-Fu Chen or Fenglin Niu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Primary Handling Editors: Stefan Lachowycz; Melissa Plail.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Seismic stations and earthquakes used in this study.

a, Study region and locations of broadband seismic stations (triangles) used in this study. The thick red lines give the location of the profiles shown in Fig. 2 in the main text. The black lines (numbered from 1 to 10) give the location of the profiles shown in Extended Data Figs. 2 and 3, to demonstrate the non-uniqueness of the phases X1 and X2. Black dashed curves show the Wadati-Benioff zone obtained from the distribution of intermediate/deep earthquakes. The red symbols indicate the Cenozoic active volcanoes in this region. b, Spatial distribution of earthquakes used in receiver function study, colored by their back azimuth. c, Histogram shows the number of receiver functions from different back azimuth.

Extended Data Fig. 2 Comparison of CCP stacking images and the tomography studies.

Receiver function common conversion point stacking images along the five profiles (1-5) shown in Extended Data Fig. 1. For comparison, the corresponding full-waveform tomographic images from Tao et al.4 are shown. The subducting Pacific slab is highlighted by positive velocity anomaly contours.

Extended Data Fig. 3 Comparison of CCP stacking images and the tomography studies.

Same as Extended Data Fig. 2, but for five profiles (6-10) shown in Extended Data Fig. 1.

Extended Data Fig. 4 Cross-correlation analyze of the phases X1 and X2 and the slab-related fast-velocity anomaly contours in tomographic studies.

We use the Pearson correlation coefficient (CC) to qualify the correlation between phases X1 ac, and X2 df, and the velocity contours. Our study suggests that the existence of the phases X1/X2 is best correlated with velocity contour of 1%, while the depth of the phases X1/X2 is best correlated with the velocity of 3%.

Extended Data Fig. 5 Multi-frequency receiver function waveform modeling.

a, The 1D velocity model set up in Receiver Function synthetic tests. b, Sensitivity to the velocity contrast. c, Sensitivity to the transition thickness. d, Sensitivity to the Gaussian filter parameter (frequency).

Extended Data Fig. 6 Multi-frequency receiver function waveform modeling results for both the synthetic data and observation.

af, Diagrams show the variation of the amplitude of the Pds phase with transition thickness, velocity perturbation and Gaussian filter parameter. Black heavy line indicates the amplitude of the 410-km discontinuity in IASP91 model49 for reference. ei, The frequency dependent amplitude of the Pds phases in real data, along with the uncertainties estimated by a bootstrapping method.

Extended Data Fig. 7 Sensitivity test for the multi-frequency receiver function waveform modeling.

a, and b, Examples show the multi-frequency Receiver Function (RF) waveforms sensitivity to the thickness and shear-wave speed. c, The RF waveforms are more sensitive to the relative velocity change along the depth, rather than the absolutely velocity value.

Extended Data Fig. 8 Estimated topography of wadsleyite-ringwoodite phase transition based on thermal anomalies from tomography models.

a, S-velocity model of FWEA18-S4, NECESS-S41 along the profile A shown in the main text. b, The estimated temperature anomaly using a temperature-velocity relationship29 of dVs/T=−3.1×10−4 km s−1K−1. The thick red line shows the estimated temperature at 520 km depth. The thin gray lines show the estimated temperature profiles over a 100 km depth interval around 520 km to accompany the resolution of tomographic studies. c, Estimated topography of wadsleyite-ringwoodite phase transition using a Clapeyron slope of 2 MPa/K23. The purple lines show the estimation, while the thick black line shows the observation. d, Similar as (c), but for a Clapeyron slope of 4 MPa/K23. Note that even though the velocity anomalies in regions A and B are very similar in magnitude, the depths of observed phase X1 have a large difference.

Extended Data Fig. 9 Comparison of different models for interpreting the observed Phase X2.

Schematic cartoons show different models/interpretations (left column), while the limitations of each model are shown in the right column29,32,35,58,59.

Extended Data Fig. 10 Comparison of a variety of tomography models along a same profile.

P-velocity model of FWEA18-P4, GAP_P42, MIT-0860 and S-velocity model of FWEA18-S4, NECESS-S41. The general features, such as the high velocity anomaly interpreted as the subducting Pacific slab and the low velocity sub-slab anomalies, can be observed in all these models. However, the distribution and amplitude of these anomalies are different from each other. The FWEA18 is expected to have higher spatial resolution than the others in the northwest Pacific region, due to the dense seismic data coverage and the usage of full-waveform inversion algorithm4. Therefore, we use the FWEA18 model to conduct 3D velocity correction in our RF analysis.

Supplementary information

Supplementary Information

Supplementary Sections 1–6 and Figs. 1–12.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, X., Chen, QF., Niu, F. et al. Distinct slab interfaces imaged within the mantle transition zone. Nat. Geosci. 13, 822–827 (2020). https://doi.org/10.1038/s41561-020-00653-5

Download citation

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing