Magma fragmentation in highly explosive basaltic eruptions induced by rapid crystallization

Article metrics


Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas inhibits fragmentation, which favours effusive and lava-fountaining activity, yet highly explosive, hazardous basaltic eruptions occur. The processes that promote fragmentation of basaltic magma remain unclear and are subject to debate. Here we used a numerical conduit model to show that a rapid magma ascent during explosive eruptions produces a large undercooling. In situ experiments revealed that undercooling drives exceptionally rapid (in minutes) crystallization, which induces a step change in viscosity that triggers magma fragmentation. The experimentally produced textures are consistent with basaltic Plinian eruption products. We applied a numerical model to investigate basaltic magma fragmentation over a wide parameter space and found that all basaltic volcanoes have the potential to produce highly explosive eruptions. The critical requirements are initial magma temperatures lower than 1,100 °C to reach a syn-eruptive crystal content of over 30 vol%, and thus a magma viscosity around 105 Pa s, which our results suggest is the minimum viscosity required for the fragmentation of fast ascending basaltic magmas. These temperature, crystal content and viscosity requirements reveal how typically effusive basaltic volcanoes can produce unexpected highly explosive and hazardous eruptions.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Crystallization through time during experiment ET1150.
Fig. 2: Plagioclase crystal morphology.
Fig. 3: Model results during magma ascent.
Fig. 4: Sensitivity analyses.

Data availability

The authors declare that the experimental and analytical data supporting the findings of this study are available within the article and its Supplementary Information. The numerical data, generated by the code, are available from the corresponding author upon request.

Code availability

The code that supports the findings and of this study and used to generate Figs. 3 and 4 is available from the corresponding author upon request.


  1. 1.

    Papale, P. Strain-induced magma fragmentation in explosive eruptions. Nature 397, 425–428 (1999).

  2. 2.

    Dingwell, D. B. Volcanic dilemma—flow or blow? Science 273, 1054–1055 (1996).

  3. 3.

    Carey, S. & Sigurdsson, H. The intensity of Plinian eruptions. Bull. Volcanol. 51, 28–40 (1989).

  4. 4.

    Wilson, L. Explosive volcanic eruptions—III. Plinian eruption columns. Geophys. J. Inter. 45, 543–556 (1976).

  5. 5.

    Polacci, M., Corsaro, R. A. & Andronico, D. Coupled textural and compositional characterization of basaltic scoria: insights into the transition from Strombolian to fire fountain activity at Mount Etna, Italy. Geology 34, 201–204 (2006).

  6. 6.

    Coltelli, M., Del Carlo, P. & Vezzoli, L. Discovery of a Plinian basaltic eruption of Roman age at Etna volcano, Italy. Geology 26, 1095–1098 (1998).

  7. 7.

    Houghton, B. F. et al. The influence of conduit processes on changes in style of basaltic Plinian eruptions: Tarawera 1886 and Etna 122 bc. J. Volcanol. Geotherm. Res. 137, 1–14 (2004).

  8. 8.

    Sable, J. E., Houghton, B. F., Del Carlo, P. & Coltelli, M. Changing conditions of magma ascent and fragmentation during the Etna 122 bc basaltic Plinian eruption: evidence from clast microtextures. J. Volcanol. Geotherm. Res. 158, 333–354 (2006).

  9. 9.

    Houghton, B. F. & Gonnermann, H. M. Basaltic explosive volcanism: constraints from deposits and models. Chem. Erde-Geochem. 68, 117–140 (2008).

  10. 10.

    Sable, J. E., Houghton, B. F., Wilson, C. J. N. & Carey, R. J. Eruption mechanisms during the climax of the Tarawera 1886 basaltic Plinian eruption inferred from microtextural characteristics of the deposits (Stud. Volcanology: Leg. George Walk. Spec. Publ. IAVCEI 2, Geological Society, 2009).

  11. 11.

    Costantini, L., Houghton, B. F. & Bonadonna, C. Constraints on eruption dynamics of basaltic explosive activity derived from chemical and microtextural study: the example of the Fontana Lapilli Plinian eruption, Nicaragua. J. Volcanol. Geotherm. Res. 189, 207–224 (2010).

  12. 12.

    Melnik, O. & Sparks, R. S. J. Nonlinear dynamics of lava dome extrusion. Nature 402, 37–41 (1999).

  13. 13.

    Gonnermann, H. M. & Manga, M. Explosive volcanism may not be an inevitable consequence of magma fragmentation. Nature 426, 432–435 (2003).

  14. 14.

    Gonnermann, H. M. Magma fragmentation. Ann. Rev. Earth Planet. Sci. 43, 431–458 (2015).

  15. 15.

    Alidibirov, M. & Dingwell, D. B. Magma fragmentation by rapid decompression. Nature 380, 146–148 (1996).

  16. 16.

    Zhang, Y. A criterion for the fragmentation of bubbly magma based on brittle failure theory. Nature 402, 648–650 (1999).

  17. 17.

    Spieler, O. et al. The fragmentation threshold of pyroclastic rocks. Earth Planet. Sci. Lett. 226, 139–148 (2004).

  18. 18.

    Kueppers, U., Scheu, B., Spieler, O. & Dingwell, D. B. Fragmentation efficiency of explosive volcanic eruptions: a study of experimentally generated pyroclasts. J. Volcanol. Geotherm. Res. 153, 125–135 (2006).

  19. 19.

    Giordano, D. & Dingwell, D. Viscosity of hydrous Etna basalt: implications for Plinian-style basaltic eruptions. Bull. Volcanol. 65, 8–14 (2003).

  20. 20.

    Moitra, P., Gonnermann, H. M., Houghton, B. F. & Tiwary, C. S. Fragmentation and Plinian eruption of crystallizing basaltic magma. Earth Planet. Sci. Lett. 500, 97–104 (2018).

  21. 21.

    La Spina, G., Burton, M., Vitturi, M. D. M. & Arzilli, F. Role of syn-eruptive plagioclase disequilibrium crystallisation in basaltic magma ascent dynamics. Nat. Commun. 7, 13402 (2016).

  22. 22.

    Cashman, K. & Blundy, J. Degassing and crystallisation of ascending andesite and dacite. Philos. Trans. R. Soc. A 358, 1487–1513 (2000).

  23. 23.

    La Spina, G., Burton, M. & de’ Michieli Vitturi, M. Temperature evolution during magma ascent in basaltic effusive eruptions: a numerical application to Stromboli volcano. Earth Planet. Sci. Lett. 426, 89–100 (2015).

  24. 24.

    Hammer, J. E. & Rutherford, M. J. An experimental study of the kinetics of decompression‐induced crystallization in silicic melt. J. Geophys. Res. Solid Earth 107, 2377 (2002).

  25. 25.

    Couch, S., Harford, C. L., Sparks, R. S. J. & Carroll, M. R. Experimental constraints on the conditions of formation of highly calcic plagioclase microlites at the Soufrire Hills Volcano, Montserrat. J. Petrol. 44, 1455–1475 (2003).

  26. 26.

    Shea, T. & Hammer, J. E. Kinetics of cooling- and decompression-induced crystallization in hydrous mafic–intermediate magmas. J. Volcanol. Geotherm. Res. 260, 127–145 (2013).

  27. 27.

    Agostini, C., Fortunati, A., Arzilli, F., Landi, P. & Carroll, M. R. Kinetics of crystal evolution as a probe to magmatism at Stromboli (Aeolian Archipelago, Italy). Geochim. Cosmochim. Acta 110, 135–151 (2013).

  28. 28.

    Vona, A. & Romano, C. The effects of undercooling and deformation rates on the crystallization kinetics of Stromboli and Etna basalts. Contrib. Mineral. Petrol. 166, 491–509 (2013).

  29. 29.

    Kolzenburg, S., Giordano, D., Hess, K. U. & Dingwell, D. B. Shear rate‐dependent disequilibrium rheology and dynamics of basalt solidification. Geophys. Res. Lett. 45, 6466–6475 (2018).

  30. 30.

    Marsh, B. D. On the interpretation of crystal size distributions in magmatic systems. J. Petrol. 39, 553–599 (1998).

  31. 31.

    Cashman, K. V. Relationship between plagioclase crystallization and cooling rate in basaltic melts. Contrib. Mineral. Petrol. 113, 126–142 (1993).

  32. 32.

    Conte, A. M., Perinelli, C. & Trigila, R. Cooling kinetics experiments on different Stromboli lavas: effects on crystal morphologies and phases composition. J. Volcanol. Geotherm. Res. 155, 179–200 (2006).

  33. 33.

    Szramek, L., Gardner, J. E. & Hort, M. Cooling-induced crystallization of microlite crystals in two basaltic pumice clasts. Am. Mineral. 95, 503–509 (2010).

  34. 34.

    Brugger, C. R. & Hammer, J. E. Crystallization kinetics in continuous decompression experiments: implications for interpreting natural magma ascent processes. J. Petrol. 51, 1941–1965 (2010).

  35. 35.

    Karagadde, S. et al. Transgranular liquation cracking of grains in the semi-solid state. Nat. Commun. 6, 8300 (2015).

  36. 36.

    Polacci, M. et al. Crystallisation in basaltic magmas revealed via in situ 4D synchrotron X-ray microtomography. Sci. Rep. 8, 8377 (2018).

  37. 37.

    Goepfert, K. & Gardner, J. E. Influence of pre-eruptive storage conditions and volatile contents on explosive Plinian style eruptions of basic magma. Bull. Volcanol. 72, 511–521 (2010).

  38. 38.

    Szramek, L. A. Mafic Plinian eruptions: is fast ascent required? J. Geophys. Res. Solid Earth 121, 7119–7136 (2016).

  39. 39.

    Suzuki, Y. & Fujii, T. Effect of syneruptive decompression path on shifting intensity in basaltic sub-Plinian eruption: implication of microlites in Yufune-2 scoria from Fuji volcano, Japan. J. Volcanol. Geotherm. Res. 198, 158–176 (2010).

  40. 40.

    Campagnola, S., Romano, C., Mastin, L. G. & Vona, A. Confort 15 model of conduit dynamics: applications to Pantelleria Green Tuff and Etna 122 bc eruptions. Contrib. Mineral. Petrol. 171, 60 (2016).

  41. 41.

    Cassidy, M., Manga, M., Cashman, K. & Bachmann, O. Controls on explosive-effusive volcanic eruption styles. Nat. Commun. 9, 2839 (2018).

  42. 42.

    Zhang, Y., Ni, H. & Chen, Y. Diffusion data in silicate melts. Rev. Mineral. Geochem. 72, 311–408 (2010).

  43. 43.

    Namiki, A. & Manga, M. Transition between fragmentation and permeable outgassing of low viscosity magmas. J. Volcanol. Geotherm. Res. 169, 48–60 (2008).

  44. 44.

    Corsaro, R. A., Miraglia, L. & Pompilio, M. Petrologic evidence of a complex plumbing system feeding the July–August 2001 eruption of Mt Etna, Sicily, Italy. Bull. Volcanol. 69, 401–421 (2007).

  45. 45.

    Lesne, P., Scaillet, B., Pichavant, M., Iacono-Marziano, G. & Beny, J. M. The H2O solubility of alkali basaltic melts: an experimental study. Contrib. Mineral. Petrol. 162, 133–151 (2011).

  46. 46.

    Drakopoulos, M. et al. I12: the Joint Engineering, Environment and Processing (JEEP) beamline at diamond light source. J. Synchrotron Radiat. 22, 828–838 (2015).

  47. 47.

    Azeem, M. A. et al. Revealing dendritic pattern formation in Ni, Fe and Co alloys using synchrotron tomography. Acta Mater. 128, 241–248 (2017).

  48. 48.

    Cloetens, P., Barrett, R., Baruchel, J., Guigay, J. P. & Schlenker, M. Phase objects in synchrotron radiation hard X-ray imaging. J. Phys. D. 29, 133–146 (1996).

  49. 49.

    O’Sullivan, J. D. A fast sinc function gridding algorithm for Fourier inversion in computer tomography. IEEE Trans. Med. Imaging 4, 200–207 (1985).

  50. 50.

    Gürsoy, D., De Carlo, F., Xiao, X. & Jacobsen, C. TomoPy: a framework for the analysis of synchrotron tomographic data. J. Synchrotron Radiat. 21, 1188–1193 (2014).

  51. 51.

    Vo, N. T., Drakopoulos, M., Atwood, R. C. & Reinhard, C. Reliable method for calculating the center of rotation in parallel-beam tomography. Opt. Express 22, 19078–19086 (2014).

  52. 52.

    Vo, N. T., Atwood, R. C. & Drakopoulos, M. Superior techniques for eliminating ring artifacts in X-ray micro-tomography. Opt. Express 26, 28396–28412 (2018).

  53. 53.

    Titarenko, S., Withers, P. J. & Yagola, A. An analytical formula for ring artefact suppression in X-ray tomography. Appl. Math. Lett. 23, 1489–1495 (2010).

  54. 54.

    Abramoff, M. D., Magalhaes, P. J. & Ram, S. J. Image processing with ImageJ. Biophoton. Int. 11, 36–42 (2004).

  55. 55.

    Arzilli, F. et al. Near-liquidus growth of feldspar spherulites in trachytic melts: 3D morphologies and implications in crystallization mechanisms. Lithos 216, 93–105 (2015).

  56. 56.

    Arzilli, F. et al. A novel protocol for resolving feldspar crystals in synchrotron X-ray microtomographic images of crystallized natural magmas and synthetic analogs. Am. Mineral. 101, 2301–2311 (2016).

  57. 57.

    Brun, F. et al. Pore3D: a software library for quantitative analysis of porous media. Nucl. Instrum. Meth. A 615, 326–332 (2010).

  58. 58.

    Ohser, J. & Mücklich, F. Statistical Analysis of Microstructure in Material Science (ed. Barnett, V.) (John Wiley & Sons, 2000).

  59. 59.

    La Spina, G., Polacci, M., Burton, M. & de’ Michieli Vitturi, M. Numerical investigation of permeability models for low viscosity magmas: application to the 2007 Stromboli effusive eruption. Earth Planet. Sci. Lett. 473, 279–290 (2017).

  60. 60.

    de’ Michieli Vitturi, M., Clarke, A. B., Neri, A. & Voight, B. Transient effects of magma ascent dynamics along a geometrically variable dome-feeding conduit. Earth Planet. Sci. Lett. 295, 541–553 (2010).

  61. 61.

    Caricchi, L. et al. Non-Newtonian rheology of crystal-bearing magmas and implications for magma ascent dynamics. Earth Planet. Sci. Lett. 264, 402–419 (2007).

  62. 62.

    Giordano, D., Russell, J. K. & Dingwell, D. B. Viscosity of magmatic liquids: a model. Earth Planet. Sci. Lett. 271, 123–134 (2008).

  63. 63.

    Del Carlo, P. & Pompilo, M. The relationship between volatile content and the eruptive style of basaltic magma: the Etna case. Ann. Geophys. 47, 1423–1432 (2004).

  64. 64.

    Costa, A., Caricchi, L. & Bagdassarov, N. A model for the rheology of particle-bearing suspensions and partially molten rocks. Geochem. Geophys. Geosyst. 10, Q0301 (2009).

  65. 65.

    Vona, A., Romano, C., Dingwell, D. & Giordano, D. The rheology of crystal-bearing basaltic magmas from Stromboli and Etna. Geochim. Cosmochim. Acta 75, 3214–3236 (2011).

  66. 66.

    Smith, P. & Asimov, P. D. Adiabat_1ph: a new public front-end to the MELTS, pMELTS, and pHMELTS models. Geochem. Geophys. Geosyst. 6, Q02004 (2005).

  67. 67.

    Ghiorso, M. S. & Sack, R. O. Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid–solid equilibria in magmatic systems at elevated temperatures and pressures. Contrib. Mineral. Petrol. 119, 197–212 (1995).

  68. 68.

    Adams, B. M. et al. Multilevel Parallel Object-Oriented Framework for Design Optimization, Parameter Estimation, Uncertainty Quantification, and Sensitivity Analysis Version 6.6 User’s Manual Technical Report SAND2014-4633 (Sandia National Laboratories, 2017).

Download references


The research leading to these results has received funding from the RCUK NERC DisEqm project (NE/N018575/1) and (NE/M013561/1). The beamtime on I12 was provided by Diamond Light Source (EE16188-1) and laboratory space by the Research Complex at Harwell. Sensitivity analyses were performed on the ARCHER National Supercomputing Service.

Author information

M.P., F.A., M.R.B. and P.D.L. conceived the research project. F.A., M.P., G.L.S., N.L.G., B.C., M.E.H., D.D.G., N.T.V., S.N., R.A., E.W.L., P.D.L., H.M.M. and M.R.B. contributed to the beamline experiments. F.A. collected the volcanic rocks for the starting material. D.D.G., H.M.M. and R.A.B. prepared the starting material. F.A., M.P., G.L.S. and N.T.V. performed image reconstruction. F.A. and M.P. performed image processing. F.A. performed the image segmentation and analysis. G.L.S. performed numerical simulations using the conduit model. R.A.B. and F.A. performed the ex situ decompression experiments. F.A. and M.E.H. performed chemical analysis. E.C.B., F.A. and G.L.S. collected samples of the Etna 122 bc Plinian eruption. E.C.B. and F.A. acquired and analysed the BSE images of Etna 122 bc Plinian eruption samples. F.A., G.L.S., M.R.B., M.P. and E.C.B. wrote the manuscript, with contributions from all the authors.

Correspondence to Fabio Arzilli.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Primary Handling Editor(s): Melissa Plail; Rebecca Neely.

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

Supplementary information

Supplementary Information

Supplementary Figs. 1–6 and Tables 1–4.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Arzilli, F., Spina, G., Burton, M.R. et al. Magma fragmentation in highly explosive basaltic eruptions induced by rapid crystallization. Nat. Geosci. (2019) doi:10.1038/s41561-019-0468-6

Download citation