Skip to main content

Thank you for visiting 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.

Explosive fragmentation of erupting magma


THE magma responsible for explosive volcanic eruptions has both a volatile and an inert phase. Deep in the conduit of an active volcano, bubbles nucleate as the volatiles exsolve1–3. As the magma rises, the bubbles grow through depressurization and continued exsolution. It is thought that when the pressure in the bubbles exceeds that in the overlying material, the magma undergoes a rapid transformation from a continuous magmatic phase with bubbles to a continuous gas phase with fragmented pyroclastic material1,2. The fragmentation process is complex and poorly understood. To understand better how the transport of fragmented material is coupled to exsolution and vaporization, we have performed depressurization experiments on a two-phase system, designed to simulate the eruption process. We identify a new explosive vaporization process, in which a fragmentation front propagates downwards through a mixture of volatile liquid and inert particulate material, suppressing the growth of nucleated bubbles by compressing the material ahead of it. This process is distinct from, and may complement, previously identified fragmentation mechanisms such as non-nucleate vaporization4 and fragmentation induced by an expanding magmatic foam5.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. Sparks, R. S. J. J. Volcan. geotherm. Res. 3, 1–37 (1978).

    CAS  Article  ADS  Google Scholar 

  2. Wilson, L., Sparks, R. S. J. & Walker, G. P. L. Geophys. J. R. astr. Soc. 63, 117–148 (1980).

    Article  ADS  Google Scholar 

  3. Hurwitz, S. & Navon, O. Earth planet. Sci. Lett. 122, 267–280 (1994).

    CAS  Article  ADS  Google Scholar 

  4. Hill, L. G. & Sturtevant, B. in Adiabatic Waves in Liquid-Vapor Systems 25–37 (Springer, New York, 1990).

    Book  Google Scholar 

  5. Mader, H. M. et al. Nature 372, 85–88 (1994).

    CAS  Article  ADS  Google Scholar 

  6. Anderson, A. T. et al. Geology 17, 221–225 (1989).

    CAS  Article  ADS  Google Scholar 

  7. Sheridan, M. F. & Wohletz, K. H. J. Volcan. geotherm. Res. 17, 1–29 (1983).

    Article  ADS  Google Scholar 

  8. Gerlach, T. M. Eos 74, 104–105 (1993) (Abstr.).

    Google Scholar 

  9. Ortiz, L. A., Scott, R. & Lee, J. Int. J. Earthquake Engng Struct. Dynam. 11, 251–268 (1983).

    Article  Google Scholar 

  10. Scott, R. Int. J. Soil Dyn. Earthquake Engng 2, 188–198 (1983).

    Article  Google Scholar 

  11. Marble, F. E. Combustion and Propulsion: High Temperature Phenomena (eds Hagerty, R. P. et al.) 175–213 (5th Agardograph Colloq., Macmillan, New York, 1963).

    Google Scholar 

  12. Wohletz, K., McGetchin, T. R., Sandford, M. T. & Jones, E. M. J. Geophys. Res. 89, 8269–8286 (1984).

    Article  ADS  Google Scholar 

  13. McBirney, A. R. & Murase, T. Bull. volcan. 34, 372–384 (1970).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sugioka, I., Bursik, M. Explosive fragmentation of erupting magma. Nature 373, 689–692 (1995).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

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.


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