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Institute of Advanced Study

Professor James Gardner

“Being part of the IAS Fellowship program allowed me the ability to explore ideas outside of my usual realm (of physical volcanology). Without my time at the IAS I would not have explored the idea of how accounts from eyewitnesses and survivors could inform our understanding of fundamental volcanological processes. These have provided glimpses of the interiors of deadly pyroclastic flows that could not be imagined otherwise. ”

Professor Jim Gardner, University of Texas at Austin

IAS Fellow at Van Mildert College, Durham University (October - December 2015)

James E. Gardner is a Professor of Geology in the Jackson School of Geosciences at the University of Texas at Austin, the flagship university of the University of Texas system. His research program broadly aims to understand the causes and consequences of explosive eruptions of volcanoes. In particular, he investigates the dynamics of magma storage beneath volcanoes before eruption, the kinetics of gas bubble formation that drives eruption, and the deposition of volcanic material on the Earth's surface during eruption. Each process must be understood before integrated models can be developed to forecast eruptive behavior and mitigate the hazards associated with them. Because most processes that occur during eruptions take place within the Earth’s crust, they cannot be observed directly. As a consequence, a major aspect of Professor Gardner's research is simulating magmatic and volcanic processes using laboratory experiments. Such experiments involve taking natural volcanic materials and subjecting them to magmatic pressures and temperatures, often reaching pressures of more than 1,000 times atmospheric pressure and temperatures over 1000 degrees Celsius, and comparing the products to natural pumice and ash.

Professor Gardner has authored or co-authored more than 180 peer reviewed papers and abstracts focused on understanding the dynamics of volcanic eruptions and the eruptive histories of volcanoes. Recent contributions on the generation of bubbles in magmas, the storage rhyolite magma before eruption, and the collapse of eruption plumes to form pyroclastic flows have been published in leading geoscience journals such as Geology, Journal of Volcanology and Geothermal Research, Geochimica Cosmochimica Acta, and Contributions to Mineralogy and Petrology. He also recently co-authored a chapter called "Timescales of Magma Degassing", which describes the nucleation and growth gas bubbles in magma and the loss of gas during eruptions, as part of the book "Timescales of Magmatic Processes", published by Wiley-Blackwell. Professor Gardner also serves as Associate Editor for the journal Bulletin of Volcanology, the leading international journal devoted to research on volcanoes and their eruptions.

Professor Gardner has been a Visiting Research Scholar at the Universidad Nacional Autónoma de México, in México City, where he helped establish the first volcano experimental laboratory in Latin America. He has also served on the staff of the Alaska Volcano Observatory. In 2002, he won the Wager Prize from the International Association of Volcanology and Chemistry of the Earth's Interior, which is given to a scientist up to 15 years after Ph.D acquisition, who has made outstanding contributions to volcanology. He was awarded an Alexander von Humboldt Fellowship in 1995.

While at the IAS at Durham, Professor Gardner plans to collaborate with the staff in the Department of Earth Sciences to integrate his research findings with numerical and physical models of magma fluid dynamics. In particular, he will undertake collaborative research with Senior Lecturer Ed Llewellin to link experimental findings with numerical models to investigate the behavior of gases in magma as it rises to the Earth's surface.

Public Lecture - Evidence for the Largest Volcanic Eruptions from the Tiniest of Bubbles and Crystals

Volcanic eruptions are awe inspiring natural events. Violent ones occur when molten rock, called magma, disintegrates and explodes into the atmosphere. Not all are violent, however, and instead magma can sometimes quiescently pour out as lava. It is critical to understand what controls whether magma erupts violently or as lava, but the lethal nature of eruptions makes them all but impossible for scientists to study up close, except in the most benign of circumstances. Even more daunting is the fact that everything that dictates eruptive behavior happens while magma is hidden from view deep in the Earth.

Volcanologists are left to seek evidence from the products of the eruption. Before erupting, magma at depth consists of hot silicate liquid with gases dissolved in it – like the carbon dioxide dissolved in champagne while still in the bottle. When those gases are released they form tiny bubbles which propel the magma upwards and drive eruptions, leaving behind cavities called vesicles. In response, the silicate liquid begins to solidify, growing micrometer sized crystals called microlites. Professor James Gardner will discuss how experimental laboratory simulations can calibrate the textures of those vesicles and microlites in order so they can be used as evidence for what happens while magma rises and ultimately erupts at the Earth’s surface.

Listen to the lecture in full.

Professor James Gardner Publications

Gardner, J.E., Llewellin, E.W., Watkins, J.M., Befus, K.S (2016) 'Formation of obsidian pyroclasts by sintering of ash particles in the volcanic conduit', Earth and Planetary Science Letters, 459(1), pp. 252-263.

Gardner, J.E., Andrews, B.J., Dennen, R (2016) 'Liftoff of the 18 May 1980 surge of Mount St. Helens (USA) and the deposits left behind', Bulletin of Volcanology, 79(1).

Gardner, J.E (2016) 'Nucleation rates of spherulites in natural rhyolitic lava', The American Mineralogist, 101(11), pp. 2367-2376

Gardner, J.E., Webster, James D (2016) 'The impact of dissolved CO2 on bubble nucleation in water-poor rhyolite melts', Chemical Geology, 420, pp.180-185.

Gardner, J. E., Jackson, B.A., Gonnermann, H., Soule, S.A. (2016) 'Rapid ascent and emplacement of basaltic lava during the 2005–06 eruption of the East Pacific Rise at ca. 9◦51'N as inferred from CO2 contents', Earth and Planetary Science Letters, 451, pp. 152–160.

IAS Insights Paper


Pyroclastic flows have been recognized as one of the most devastating hazards of volcanic eruptions ever since one killed nearly 28,000 people in the town of St Pierre in 1902 AD. After more than 100 years, however, there are aspects about them that scientists still do not understand, including where they will go, how far they will travel, how their velocity varies laterally and vertically, and how volcanic ash is transported within them to be deposited on the ground. Scientists rely on indirect evidence from their ash deposits or from computer models to hypothesize about such unknowns. The fundamental problem is that no one has made in situ measurements within the flows. Despite their lethal nature, however, some people have lived through them. While being enveloped by searing hot ash must be unimaginably traumatic, it is possible that survivors remember details that could help inform scientists, especially if a collective memory can be developed from multiple accounts. This study uses recollections from eyewitnesses and survivors of the 18 May 1980 pyroclastic flow from Mount St Helens to develop a collective memory that shows the leading edge of the flow is relatively ash poor, cold and even carrying ice. It is shown that this collective memory is likely sound by comparing it to the physical record of the flow from its impact on inanimate objects. What is gained is that a cold flow front would not have otherwise been imagined. It is hoped that if future encounters occur, scientists seek out eyewitnesses and survivors to gain new and potentially unexpected evidence about pyroclastic flows.

Insights Paper