# Antonio Costa (geophysicist)

Antonio Costa is a geophysicist and academic. He is a Senior Researcher at the National Institute of Geophysics and Volcanology (INGV) Branch of Bologna, and an adjunct professor at the University of Bologna, in Bologna, Italy.
Costa's research interests included the coupled fluid-rock dynamics of magmatic and volcanic processes, magma properties, hydrothermal system fluid flows and geothermal energy, volcanic plume dynamics, tephra dispersal, atmospheric transport of volcanic ash and gases, volcanic lakes, lava flow modeling, volcanic tsunamis, volcanic impacts on climate and society, and natural hazard assessment. He received the Wager Medal from the International Association of Volcanology and Chemistry of the Earth's Interior in 2013 and has been listed among the "World's Top 2% Scientists" since 2019.
Costa has been an elected member of Academia Europaea. He served as the Editor in Chief of Annals of Geophysics (2017-2019); and Topical Editor of Natural Hazards and Earth System Sciences (2011-2015).

## Education and early career

Costa received his degree in Physics at the University of Pisa in October 1998 with a thesis on "Rotation of magnetized plasmas during ICHR". Following this, he served as a Teacher of Mathematics and Physics for MIUR in Milano and completed his PhD in Environmental Physics from the University of Bologna in 2004 with a thesis titled "Themo-fluid-dynamic models applied to transport process of volcanic products". During his PhD, he spent 6 months at The Open University, UK, in the framework of an EU Research Training program. He then served as a Postdoc Grant recipient at Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano in Naples, Italy, from January 2004 to May 2005 and subsequently serving as a Post-Doctoral Research Associate at the University of Bristol from 2005 to 2006, where he was also an honorary research visitor from 2007 to 2010. He continued his research journey as a Permanent Researcher from 2007 to 2010 at Osservatorio Vesuviano, Naples, Italy.

## Career

Costa became a Research Fellow in the Environmental Systems Science Centre at the University of Reading, UK, from January 2011 to December 2012. From 2013 he served as a Researcher at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna. From April to July 2015 he was a Visiting Researcher at the Earthquake Research Institute at the University of Tokyo in Japan. Following this, he became a Senior Researcher at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, from November 2018, and was a Fellow of the Center for Advanced Studies (CAS) at the Ludwig-Maximilians-Universitat Munchen in Germany, from May to June 2019.
Costa became the managing director of the INGV Branch of Bologna from September 2019 to August 2022. Since September 2022, he has been serving as a Senior Researcher at the Istituto Nazionale di Geofisica e Vulcanologia of Sezione di Bologna, Italy.

## Research

Costa's primary research interests revolve around the fluid mechanics of volcanic processes, particularly emphasizing magma ascent dynamics, magma properties, models for geophysical flows, atmospheric gas dispersion, atmospheric transport of volcanic ash, and natural hazard and risk assessment.

### Volcanology

Costa introduced a semiempirical model that accurately predicted the effective relative viscosity of crystal-bearing magmas across diverse suspended solid configurations, showcasing its utility in comprehending magma behavior through parameter adjustments within fitting ranges. He developed magma ascent models that enlightened the controls of conduit geometry and wallrock elasticity on lava dome and explosive eruptions.
In collaboration with Costanza Bonadonna, Costa introduced an empirical approach for estimating tephra-deposit volumes, utilizing the integration of the Weibull function. He is also one of the lead authors of the FALL3D model. With Yujiro Suzuki, he coordinated the international study on Eruption Column Model Inter-comparison of the IAVCEI Commission on Tephra Hazard Modelling.

### Geophysical fluid dynamics

Costa's research on fluid dynamics presented a new equation relating permeability and porosity, derived from classical methods and fractal geometry; the Kozeny-Carman approach, with only two parameters.
Among Costa's research works is the exploration of thermal effects on the dynamics of temperature-dependent fluids as well as of rheological properties of high-solid suspensions, with a focus on silicate melts, and the proposal of semiempirical models describing the effective relative viscosity of crystal-bearing magmas and partially melted rocks as a function of crystal fraction, crystal shape, and strain rate backed up by extensive experimentation.

### Natural hazards

In 2016 Costa was lead author of the report for the International Atomic Energy Agency (IAEA) on Volcanic Hazards Assessment for Nuclear Installations: Methods and Examples in Site Evaluation. More recently in 2022, he served as the contributing author of reports addressing methodologies and case studies for coastal nuclear safety, emphasizing defense in depth post-2004 Indian Ocean Tsunami and 2011 Fukushima Daiichi incident, and the use of validated numerical models for tsunami hazard evaluation.

## Awards and honors

* 2013 – Wager Medalist, International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI)

## Selected articles

* Costa, A. (2006). Permeability-porosity relationship: A reexamination of the Kozeny-Carman equation based on a fractal pore-space geometry assumption. Geophysical research letters, 33(2).
* Costa, A., Macedonio, G., & Folch, A. (2006). A three-dimensional Eulerian model for transport and deposition of volcanic ashes. Earth and Planetary Science Letters, 241 (3–4), 634–647.
* Costa A., Macedonio G. (2005) Viscous heating effects in fluids with temperature-dependent viscosity: triggering of secondary flows, J. Fluid Mech., 540, 21-38
* Costa, A., Caricchi, L., & Bagdassarov, N. (2009). A model for the rheology of particle-bearing suspensions and partially molten rocks. Geochemistry, Geophysics, Geosystems, 10 (3).
* Costa, A., Folch, A., Macedonio, G., Giaccio, B., Isaia, R., & Smith, V. C. (2012). Quantifying volcanic ash dispersal and impact of the Campanian Ignimbrite super-eruption. Geophysical research letters, 39(10).