Physical Volcanology and Environmental Multiphase Flow at Georgia Tech

Kalymnos

Kos

Nisyros

Tilos

Bodrum

2

N

Vathi

0 5 10

km

Mars

Venus

Prof. Joe Dufek

Multiphase flows shape the landscape of all terrestrial planets and dictate interactions at the inte rface of the solid surface and the atmosphere, transforming the biosphere on Earth. Examples of multiphase flows include deadly explosive volcanic eruptions, Martian dust storms, sediment-choked rivers, and planetary accretion. Although extremely common, the cumulative expression of numerous particle-particle and particle-fluid interactions can produce emergent meso-scale structure and self-organization that is poorly understood and difficult to predict.

Our research is primarily focused on the application of fluid dynamics to understand mass and energy transfer in geological processes, with particular emphasis on igneous systems. Most processes in nature involve multiple phases: for instance ash particles interacting with a turbulent gas carrier phase in an explosive volcanic eruption or bubbles exolving and interacting with magma in a volcanic conduit. One of our research goals is to delineate how multiphase interactions contribute to the structure and composition of igneous systems, and the role of such interactions in determining the dynamics and deposit architecture of explosive volcanic eruptions and to the production of the crust on Earth and other planets.

To examine these problems we use a combination of field, computational and laboratory experiments. In 2008 we will be establishing in the School of Earth and Atmospheric Sciences at Georgia Tech one of the larger computational facilities devoted to simulations of volcanic phenomena. These facilities will enable high-resolution simulations of turbulent explosive volcanic eruptions, magma dynamics in the crust, and the exchange of mass and energy between the mantle and the crust. We also have a laboratory facility to examine multiphase mixing, and turbulent and granular flows. Field studies and study of remote observations provide the fundamental constraints to our physical models, and students and postdocs will have the opportunity to participate in field work locations in North America, South America and Europe. Likewise, planetary phenomena on Mars, Venus and the Jovian moons is constrained by remote sensing from orbital spacecraft.

Computer simulation of melt dynamics near the crust/mantle boundary (Chris Huber).

Field Locations

Our group has conducted and plans to conduct research in the American West, the Andes, and in the Aegean Arc. We also utilize the next generation of remote sensing of planetary surfaces and interiors to examine processes on Mars, Venus and the Jovian moons.

Often times, deposits provide the most useful information on past events, and we focus on testing our physical models with field derived depositional data.

Computer simulation of a steam explosionwhen a pyroclastic flow from Montserratenters the ocean.

Computer Simulations

Particle segregation in a hot, particle-laden current.

For more information visit our website at: http://shadow.eas.gatech.edu/~dufek/ or email: dufek@gatech.edu

The School of Earth and Atmospheric Science at Georgia Tech

The physical volcanology group at Georgia Tech is part of the interdisciplinary focus on natural hazards. Researchers in the School of the Earth and Atmospheric Science conduct cutting edge research on volcanic eruptions, seismic hazards, hurricane occurrence and dynamics, tsunami hazards and climate change. Volcanology is by its very nature a multidisciplinary field, and students will have the opportunity to interact with faculty researchers in geophysics, atmospheric and ocean sciences, planetary science, engineering, and the center for nonlinear science.

Website for more information on the Geophysics group at Georgia Tech:http://geophysics.eas.gatech.edu/

Other faculty in Earth and Atmospheric Science with Ties to solid earth and surface flows:-Prof. Dominic Assimaki: (adjunct) Numerical methods in earthquake engineering and site response- Prof. Josef Dufek: Volcanology/petrology and multi-phase flow modeling- Prof. Kurt Frankel: Active Tectonics, Tectonic Geomorphology, cosmogenic nuclide geochronology- Prof. Leonid Germanovich: (adjunct) Rock/fracture mechanics, earth/extraterrestrial materials, applied mathematics- Prof. Andrew Newman: Earthquake and volcano geodesy and seismology- Prof. Carol Paty: Planetary magnetospheric science/plasma physics - Prof. Zhigang Peng: earthquake seismology- Dr. Wenyue Xu: Geologic fluid flow and chemical transport, high-performance computing

Why Georgia Tech?

The Georgia Institute of Technology is one of the nation's top research universities, distinguished by its commitment to improving the human condition through advanced science and technology. Georgia Tech's campus occupies 330 acres in the heart of the lively, progressive city of Atlanta, where more than 17,000 undergraduate and graduate students receive a focused, technologically-based education.

Georgia Tech offers many nationally recognized, top-ranked programs and our students learn from world-class teachers and scholars working at the frontiers of science and technology. The Institute consistently ranks among U.S. News & World Report's top ten public universities in the United States.

2Laboratory Studies of Granular and Multiphase Fluids

A.

C.

D.Experiments are used understand granular and fluid interactions that are important for large-scale natural flows. Examples: A. Mixing in hot particle-laden gravitycurrent, B. Ash initiated steam explosion, C. Granular interactions under Martian conditions, D. High veloictyparticle-water interaction, E. Hydrodynamic instabiliity initiated by a shock and phase change.

B.

E.