DisEqm: quantifying disequilibrium processes in basaltic volcanism

The core aim of the NERC-NSF DisEqm project is to create an empirically-constrained quantitative understanding of disequilibrium processes in basaltic volcanism, and to apply this to address key volcanological problems through a new numerical modelling framework.


  • Overview

    Project overview

    Basaltic volcanism is the most common form of volcanism in the solar system. On Earth, eruptions can impact global and regional climate, and threaten populations living in their shadow, through a combination of ash, gas and lava emissions. The specific risk to the UK from an Icelandic eruption is recognized as one of the four ‘highest priority risks’ in the National Risk Register of Civil Emergencies. The impact of an eruption is determined by both intensity and style, ranging from explosive and ash-rich (impacting on air-space access and climate) to effusive and gas-rich (affecting climate, public health and crops/livestock locally and distally).

    Understanding these eruptive styles, and their evolution in time and space is key to forecasting the impacts of eruptions.
    In order to meet this core aim, we bring together a world-leading team to perform experiments using new, ground-breaking synchroton X-ray imaging and rheometric techniques to visualise and quantify crystallisation, degassing and multiphase, HPHT (high-pressure, high-temperature) viscosity evolution, revolutionising the fields of experimental petrology and HPHT rheometry. We will perform large scale fluid dynamics simulations to inform and test the 3D numerical modelling, and we will constrain fragmentation and eruption column processes with empirical field studies.
    Results will be integrated into a state-of-the-art numerical model, and applied to impact-focussed case studies for Icelandic, US and Italian basaltic eruptions. In conclusion, our project will produce a paradigm shift in our understanding of disequilibrium processes during magma ascent and our capacity for modelling basaltic eruption phenomena, creating a step-change in our ability to forecast and quantify the impacts of basaltic eruptions.

  • Objectives

    The main aim of the DisEqm project are to improve our understanding of kinetically-limited crystal growth and gas exolsution during ascent of baslatic magma. In order to acheive this aim, we have defined a series of objectives, which describe the methodologies that we will apply in order to advance our scientific understanding of baslatic volcanism and the impact of the DisEqm project

    • Develop and apply 4D in-situ X-ray tomography of HPHT experiments to quantify the equlilbrium and disequilibrium crystallisation and degassing behaviour of natural basaltic melt
    • Develop new HPHT apparatus for direct rheometry of basaltic melts
    • Build scaled analogue models to examine multiphase fluid flow in a fissure system
    • Create a tested, physically-based numerical model for disequilibrium ascent and eruption of basaltic magma, starting in 1D and extending to 3D using the OpenFOAM framework

    Apply the model to examine questions regarding:

    • What allows basaltic systems to produce a wide range of eruption styles and scales?
    • What role do disequilibrium processes play in this diversity?
    • Why do individual volcanoes exhibit a wide range of eruptive behaviour, often changing style and scale over short timescales?
    • What conditions lead to highly explosive basaltic eruptions such as the subplinian Sunset Crater eruption, among others?
    • How can we better interpret surface gas composition and flux measurements in terms of subsurface magma dynamics?

    In collaboration with the Steering Committee, we will define future scenarios for Icelandic, Italian and continental US eruptions, and run the DisEqm model to produce eruption source parameters for each scenario

    • We will encourage the adoption of models arising from DisEqm for use during volcanic crises.


  • Project updates and news

    EarthArt Fellowship - Stephen Cornford


    The Bristol University has been running "EarthArt Fellowship" scheme to support an artist in residence porision for some years now. The artist will be based at Bristol working part-time on this project for the next 6 months.

    After selection process, Stephen Cornford has been appointed. Stephen is quite an established artist with interestes in materials and imaging technologies. You can see some of his work here.

    The project will culminate in an exhibition of some description (the nature of which will depend on what the art is). Usually these are based in our EarthArt gallery at the entrance to the School of Earth Sciences at the Bristol University. We hope that the exhibition can travel to the other institutions.

    Congratulations, Stephen.




  • Abstracts and publications


    Pre- and syn-eruptive conditions of a  basaltic Plinian eruption at Masaya Volcano, Nicaragua: The Masaya Triple Layer (2.1 ka)

    Bamber, E. C., Arzilli, F., Polacci, M., Hartley, M. E., Fellowes, J., Di Genova, D., Chavarría, D., Saballos, J. A. & Burton, M. R., 15 Feb 2020, In : Journal of Volcanology and Geothermal Research. 392, p. 1-16 16 p., 106761.

    Research output: Contribution to journal › Article

    DOI: 10.1016/j.jvolgeores.2019.106761


     Conduit dynamics of highly explosive basaltic eruptions: The 1085 CE Sunset Crater sub-Plinian events

     La Spina, G., Clarke, A. B., De' Michieli Vitturi, M., Burton, M., Allison, C. M., Roggensack, K. & Alfano, F., 2019, In : Journal of Volcanology and Geothermal Research.

     Research output: Contribution to journal › Article

     DOI: 10.1016/j.jvolgeores.2019.08.001 

    Mechanisms of ash generation at basaltic volcanoes: the case of Mount Etna, Italy 

    Polacci, M., Andronico, D., Vitturi, M. D. M., Taddeucci, J. & Cristaldi, A., 9 Jul 2019, (Accepted/In press) In : Frontiers in Earth Science : Volcanology.

     Research output: Contribution to journal › Article

     DOI: 10.3389/feart.2019.00193

     Experimental observations of bubbling regimes at in-line multi-orifice bubblers

     Capponi, A. and Llewellin, E.W., May 2019, In : International Journal of Multiphase Flow

     Research output: Contribution to journal > Article

    DOI: 10.1016/j.ijmultiphaseflow.2019.02.008

    Insights into geological processes with CO2 remote sensing – A review of technology and applications

    Queißer, M., Burton, M. & Kazahaya, R., Jan 2019, In : Earth-Science Reviews.

    Research output: Contribution to journal › Article

    DOI: 10.1016/j.earscirev.2018.11.016

    The unexpected explosive sub-Plinian eruption of Calbuco volcano (22–23 April 2015; southern Chile): Triggering mechanism implications

    Arzilli, F., Morgavi, D., Petrelli, M., Polacci, M., Burton, M., Di Genova, D., Spina, L., La Spina, G., Hartley, M. E., Romero, J. E., Fellowes, J., Diaz-alvarado, J. & Perugini, D., 2019, In : Journal of Volcanology and Geothermal Research.

    Research output: Contribution to journal › Article

    DOI: 10.1016/j.jvolgeores.2019.04.006


     X-ray phase-contrast imaging with engineered porous materials over 50 keV

     Wang, H., Cai, B.,  Pankhurst  M. J., Zhou T., Kashyap, Y.,  Atwood, R.C., Le Gall, N., Lee, P.D.,  Drakopoulosa, M.,  Sawhney, K., July 2018, In : Journal of Synchrotron Radiation

     Research output: Contribution to journal > Article

    DOI: 10.1107/S1600577518005623

     Spatter matters – distinguishing primary (eruptive) and secondary (non-eruptive) spatter deposits

     Jones, T. J.,  Houghton, B. F., Llewellin, E. W., Parcheta, C. E., Höltgen, L., June 2018, In : Scientific Reports

     Research output: Contribution to journal > Article

    DOI: 10.1038/s41598-018-27065-1

    Magmatic densities control erupted volumes in Icelandic volcanic systems

    Hartley, M. & Maclennan, J., 4 Apr 2018, In : Frontiers in Earth Science.

    Research output: Contribution to journal › Article

    DOI: 10.3389/feart.2018.00029

    Crystallisation in basaltic magmas revealed via in situ 4D synchrotron X-ray microtomography

    Polacci, M., Arzilli, F., La Spina, G., Le Gall, N., Cai, B., Hartley, M., Di Genova, D., Vo, N. T., Nonni, S., Atwood, R. C., Llewellin, E. W., Lee, P. & Burton, M. R., 2018, In : Scientific Reports. 8, 8377.

    Research output: Contribution to journal › Article

    DOI: 10.1038/s41598-018-26644-6

    SO2 emissions, plume heights and magmatic processes inferred from satellite data: The 2015 Calbuco eruptions

    Pardini, F., Burton, M., Arzilli, F., La Spina, G. & Polacci, M., 2018, In : Journal of Volcanology and Geothermal Research.

    Research output: Contribution to journal › Article

    DOI: 10.1016/j.jvolgeores.2018.08.001

    Tephra from the 3 March 2015 sustained column related to explosive lava fountain activity at Volcán Villarrica (Chile)

    Romero, J. E., Vera, F., Polacci, M., Morgavi, D., Arzilli, F., Ayaz Alam, M., Bustillos, J., Guevara, A., Johnson, J. B., Palma, J. L., Burton, M., Cuenca, E. & Keller, W., 2018, In : Frontiers in Earth Science. 6, p. 98

    Research output: Contribution to journal › Article

    DOI: 10.3389/feart.2018.00098

     Enabling three-dimensional densitometric measurements using laboratory source X-ray micro-computed tomography

     Pankhurst, M.J., Fowler, R., Courtois, L., Nonni, S., Zuddas F., Atwood, R.C., Davis, G.R. , Lee, P.D. , January 2018, In : SoftwareX

     Research output: Contribution to journal > Article

    DOI: 10.1016/j.softx.2018.03.004


     Proximal lava drainage controls on basaltic fissure eruption dynamics

     Jones, T.J., Llewellin, E.W., Houghton, B.F., Brown, R.J., Vye-Brown, C., November 2017, In : Bulletin of Volcanology 

     Research output: Contribution to journal > Article

    DOI: 10.1007/s00445-017-1164-2

    Numerical investigation of permeability models for low viscosity magmas: application to the 2007 Stromboli effusive eruption.

    La Spina, G., Polacci, M., Burton, M. & de'Michieli Vitturi, M., 2017, In : Earth and Planetary Science Letters.

    Research output: Contribution to journal › Article

    DOI: 10.1016/j.epsl.2017.06.013


    Role of syn-eruptive plagioclase disequilibrium crystallization in basaltic magma ascent dynamics

    La Spina, G., Burton, M., de'Michieli Vitturi, M. & Arzilli, F., 12 Dec 2016, In : Nature Communications. 7, 13402, p. 1-10 10 p., 13402.

    Research output: Contribution to journal › Article

    DOI: 10.1038/ncomms13402

  • Presentations and posters


    Tracing magma degassing using experimental approaches.

    Le Gall N., Pichavant M., Burton M.R., Lee P.D. 12 Dec 2016 

    Goldschmidt August 2018, Boston, USA (invited).

    Non equilibrium degassing of ascending basalt.

    Le Gall N., Pichavant M., Burton M.R., Lee P.D. 

    January 2018, The University of Oxford, UK (invited).

    The role of sulfides in controlling volcanic SO2 emissions from Icelandic eruptions: a textural approach

    Hartley M., Liu E., Edmonds M., Arzilli F., Polacci M., Bell S., Le Gall N., Ilyinskaya E., Burton M.R., Drakopoulos M., Vo N

    IAVCEI August 2017, Portland, USA.

    4D crystallisation in basaltic magmas

    Polacci M., Arzilli F., Le Gall N., La Spina G., Cai B., Hartley M., Di Genova D., Vo N., Nonni S., Llewellin E.W., Atwood R.C., Lee P.D. and Burton M.R.

    IAVCEI August 2017, Portland, USA.

    Illuminating magma shearing processes via synchrotron imaging

    Lavallée Y., Cai B., Coats R., Kendrick J.E., von Aulock F., Wallace P.A., Le Gall N., Godinho J., Dobson K., Atwood R.C., Holness M., Lee P.D.

    EGU April 2017, Vienna, Austria (invited).

    Degassing of basaltic magma: decompression experiments and implications for interpreting the textures of volcanic rocks.

    Le Gall N., Pichavant M., Cai B., Lee P.D., Burton M.R.

    EGU April 2017, Vienna, Austria (invited).


    Rapid growth of plagioclase: implications for basaltic Plinian eruption

    Arzilli F. Polacci, M., La Spina, G., Le Gall, N., Cai, B., Hartley, M., Di Genova, D., Vo, N., Bamber, E., Nonni, S., Atwood, R.C., Llewellin, E., Lee P.D., Burton, M.

    EGU April 2018, Vienna, Austria.

    Development of a rig for the in situ synchrotron X-ray imaging of the nucleation and growth of bubbles and crystals in basaltic magmas.

    Le Gall N., Cai B., Arzilli F., Atwood R.C., Marussi S., Nonni S., Rockett P., Brooker R., Lee P.D.

    EUROMAT September 2017, Thessaloniki, Greece.

    Time-resolved synchrotron tomography of basaltic magmas: successes and challenges

    Le Gall N., Arzilli F., Cai B., Atwood R.C., Rockett P., Nonni S., Marussi S., Brooker R., Polacci M., Burton M.R., Lee P.D.

    IAVCEI August 2017, Portland, USA

    A history of vesicles and crystals in volcanic rocks in 3 and 4 dimensions

    Polacci M.

    EGU April 2017, Vienna, Austria

  • Group members

    Group members login: please click here





    Role and Personal Profile

    Fabio Arzilli

    University of Manchester


    PDRA working on Petrological experiments, 3D reconstructions and HPHT apparatus development

    Richard Brooker

    University of Bristol

    School of Earth Sciences

    Petrological experiments and HPHT apparatus development

    Mike Burton

    University of Manchester


    Project coordinator and leading eruption scenario impact assessments

    Biao Cai

    University of Manchester


    PDRA working on 4D X-ray experiments

    Antonio Capponi

    Durham University

    Dept. Earth Sciences

    PDRA working on analogue experiments

    Amanda Clarke

    Arizona State University


    Leader of eruption column modelling and field testing

    Danilo Di Genova

    University of Bristol

    School of Earth Sciences

    PDRA working on HPHT rheometer development

    Margaret Hartley

    University of Manchester


    Leader of petrology work package

    Giuseppe La Spina

    University of Manchester


    Leader of numerical modelling

    Nolwenn Le Gall

    University College London

    Dept. Mechanicla Engineering

    PDRA working on 4D X-ray experiments and petrology

    Peter Lee

    University College London

    Dept. Mechanical Engineering

    Leader of 4D X-ray work package

    Ed Llewellin

    Durham University

    Dept. Earth Sciences

    Leader of analogue modelling work package

    John Maclennan

    University of Cambridge

    Dept. Earth Sciences

    Petrological analysis and icelandic field studies

    Heidy Mader

    University of Bristol

    School of Earth Sciences

    Leader of HPHT rheometer development

    Margherita Polacci

    University of Manchester


    Leader of 4D image analysis

    Kurt Roggensack

    Arizona State University


    Petrological analysis and sunset crater studies

    Sara Nonni

    University of Manchester


    PDRA working on 4D x-ray experiments

    Peter Rockett

    University of Oxford


    Consultant on 4D x-ray experimental rig design

  • Steering Committee

    The Steering Committee has the purpose of oversight of the DisEqm project, guaranteeing that the focus remains clear on the main impact-focused goals of the project from start to finish.

    It's members represent key stakeholders in European and US Volcanology.





    Sara Barsotti Icelandic Metereological Office
    Mattia de'Michieli Vitturi Istituto Nazionale di Geofisica e Vulcanologia, Pisa Italy
    Hans Schwaiger Alaska Vocano Observatory
    Daniela Ehgartner Anton Paar
    Thor Thordarson University of Iceland
    Claire Witham UK Met Office
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