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.

  • Letter
  • Published:

Melt to mush variations in crustal magma properties along the ridge crest at the southern East Pacific Rise

Nature volume 394, pages 874–878 (1998)Cite this article

Abstract

The determination of along-axis variations in melt properties within the crustal axial magma chamber beneath fast spreading axes is important for understanding melt delivery from the mantle, eruption history along the ridge crest, and the process of crustal accretion. Seismic reflection images1,2,3,4 have shown the molten sill to be continuous along the ridge crest for many tens of kilometres with varying widths (250–4,500?m), but variations in its seismic properties and thickness have remained elusive, despite several attempts to constrain these properties5,6,7. Here we report that the melt sill along the southern East Pacific Rise, which is about 50?m thick, undergoes abrupt changes in its internal properties, ranging from pure melt to mush. The 60-km-long ridge-crest segment near 14°?00′?S is characterized by three 2–4-km sections containing pure melt embedded within a magma chamber rich in mush. These small pure melt pockets may represent a fresh supply of magma from the mantle, capable of erupting and forming the upper crust. Conversely, the 80–90% of the magma chamber which is mushy is unlikely to erupt and may influence the lower-crustal accretion.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Study area.
Figure 2: Common mid-point gathers and theoretical reflection coefficients.
Figure 3: Results of waveform inversion.
Figure 4: Results of stacking of final interpretation.

Similar content being viewed by others

References

  1. Detrick, R. S. et al. Multi-channel seismic imaging of a crustal magma chamber along the East Pacific Rise. Nature 326, 35–41 (1987).

    Article  ADS  Google Scholar 

  2. Detrick, R. S. et al. Seismic structure of the southern East Pacific Rise. Science 259, 499–503 (1993).

    Article  ADS  CAS  Google Scholar 

  3. Kent, G. M., Harding, A. J. & Orcutt, J. A. Evidence for a smaller magma chamber beneath the East Pacific Rise at 9°?30′?N. Nature 344, 650–653 (1990).

    Article  ADS  Google Scholar 

  4. Mutter, J. C. et al. Magma distribution across ridge axis discontinuities on the East Pacific Rise from multi-channel seismic images. Nature 336, 156–158 (1988).

    Article  ADS  Google Scholar 

  5. Hussenoeder, S. A. et al. Seismic analysis of the axial magma chamber reflector along the southern East Pacific Rise from conventional reflection profiling. J. Geophys. Res. 101, 22087–22105 (1996).

    Article  ADS  Google Scholar 

  6. Collier, J. S. & Singh, S. C. Detailed structure of the top of the melt body beneath the East Pacific Rise at 9°?40′?N from waveform inversion of seismic reflection data. J. Geophys. Res. 102, 20287–20304 (1997).

    Article  ADS  Google Scholar 

  7. Kent, G. M., Harding, A. J. & Orcutt, J. A. Distribution of magma beneath the East Pacific Rise between the Clipperton transform and the 9°?17′ Deval from forward modelling of common depth point data. J. Geophys. Res. 98, 13945–13970 (1993).

    Article  ADS  Google Scholar 

  8. Kent, G. M., Harding, A. J. & Orcutt, J. A. Uniform accretion of oceanic crust south of the Garrett transform at 14°?15′?S on the East Pacific Rise. J. Geophys. Res. 99, 9097–9116 (1994).

    Article  ADS  Google Scholar 

  9. Tolstoy, M. et al. Deepening of the axial magma chamber on the southern East Pacific Rise towards the Garrett Fracture Zone. J. Geophys. Res. 102, 3097–3108 (1997).

    Article  ADS  Google Scholar 

  10. Schmeling, H. Numerical models on the influence of partial melt on elastic, anelastic and electrical properties of rocks: I Elasticity and anelasticity. Phys. Earth. Planet. Inter. 41, 34–57 (1985).

    Article  ADS  Google Scholar 

  11. Murase, T. & McBirney, A. R. Properties of some common igneous rocks and their melts at high temperature. Geol. Soc. Am. Bull. 84, 3563–3592 (1973).

    Article  ADS  CAS  Google Scholar 

  12. Manghnani, M. H., Sato, H. & Rai, C. S. Ultrasonic velocity and attenuation measurements on basalt melts to 1500?°C: Role of composition and structure in the visco-elastic properties. J. Geophys. Res. 91, 9333–9342 (1986).

    Article  ADS  CAS  Google Scholar 

  13. Mainprice, D. Modelling the anisotropic seismic properties of partially molten rocks found at mid-ocean ridges. Tectonophysics 279, 161–179 (1997).

    Article  ADS  Google Scholar 

  14. Marsh, B. D. Magma chamber. Annu. Rev. Earth Planet. Sci. 17, 439–474 (1989).

    Article  ADS  CAS  Google Scholar 

  15. Batiza, R. & Niu, Y. Petrology and magma chamber processes at the East Pacific Rise. J. Geophys. Res. 97, 6779–6797 (1992).

    Article  ADS  CAS  Google Scholar 

  16. Hooft, E. E., Detrick, R. S. & Kent, G. M. Seismic structure and indicators of magma budget along the southern East Pacific Rise. J. Geophys. Res. 102, 27319–27340 (1997).

    Article  ADS  CAS  Google Scholar 

  17. Collier, J. S. & Sinha, M. C. Seismic mapping of a magma chamber beneath the Valu Fa Ridge, Lau basin. J. Geophys. Res. 97, 14031–14053 (1992).

    Article  ADS  Google Scholar 

  18. Macdonald, K. C. et al. Anew view of the mid-ocean ridge from the behaviour of ridge-axis discontinuities. Nature 335, 217–225 (1988).

    Article  ADS  Google Scholar 

  19. Sinton, J. M. et al. Magmatic process at superfast spreading mid-ocean ridges: Glass compositional variations along the East Pacific Rise 13°–23°?S. J. Geophys. Res. 96, 6133–6155 (1991).

    Article  ADS  Google Scholar 

  20. Langmuir, C. H., Bender, J. F. & Batiza, R. Petrological and tectonic segmentation of the East Pacific Rise. Nature 322, 422–429 (1986).

    Article  ADS  CAS  Google Scholar 

  21. Worster, M. G., Huppert, H. E. & Sparks, R. S. Convection and crystallisation in magma cooled from above. Earth Planet. Sci. Lett. 101, 79–89 (1990).

    Article  ADS  Google Scholar 

  22. Scott, D. R. & Stevenson, D. J. Aself-consistent model of melting, magma migration and buoyancy-driven circulation beneath mid-ocean ridges. J. Geophys. Res. 94, 2973–2988 (1989).

    Article  ADS  Google Scholar 

  23. Kormendi, F. & Dietrich, M. Non-linear waveform inversion of plane-wave seismograms in stratified elastic media. Geophysics 56, 664–674 (1991).

    Article  ADS  Google Scholar 

  24. Christeson, G. L., Wilcock, W. S. D. & Purdy, G. M. The shallow attenuation structure of the fast-spreading East Pacific Rise near 9°?30′?N. Geophys. Res. Lett. 21, 321–324 (1994).

    Article  ADS  Google Scholar 

  25. Tarantola, A. Inverse Problem Theory (Elsevier, New York, (1987)).

Download references

Acknowledgements

This work started when one of us (S.C.S.) was a Cecil Green Scholar at Scripps Institute of Oceanography. J.S.C. is supported by a NERC (BRIDGE) fellowship. Critical reviews from R.Detrick, M. Sinha and J. Garmany significantly improved this Letter.

Author information

Authors and Affiliations

  1. BIRPS, Bullard Laboratories, University of Cambridge, CB3 0EZ, Cambridge, UK

    S. C. Singh & J. S. Collier

  2. Ida & Cecil Green Institute of Geophysics and Planetary Physics, University of California, San Diego, La Jolla, 92093, California, USA

    G. M. Kent, A. J. Harding & J. A. Orcutt

Authors
  1. S. C. Singh
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. G. M. Kent
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. S. Collier
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. A. J. Harding
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. J. A. Orcutt
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to S. C. Singh.

Supplementary Information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Singh, S., Kent, G., Collier, J. et al. Melt to mush variations in crustal magma properties along the ridge crest at the southern East Pacific Rise. Nature 394, 874–878 (1998). https://doi.org/10.1038/29740

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/29740

This article is cited by

Comments

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.

Search

Advanced 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