- Ph.D. University of Arizona, Tucson, AZ. (2003)
- Dissertation title: Investigations into young outflow channels on Mars
- Major: Geosciences (advisor: Victor Baker)
- Minor: Planetary Sciences (advisor: Alfred McEwen)
- M.S. University of Iowa, Iowa City, IA. (1998)
- M.A. St. John’s College, Santa Fe, NM. (1996)
- Liberal Arts Classical and Modern Philosophy
- B.S. United States Naval Academy, Annapolis, MD. (1989), Distinguished graduate
- Political Science (Honors Program)
As a planetary geomorphologist, I study the shapes and landscape of the surfaces of planetary bodies to gain insight into their formative processes and to discern past and present influences. The ultimate goal is to contribute to understanding the distribution, movement, and evolution of material in our Solar System and its present or potential niches of habitability.
My approaches in this work involve the use of spacecraft images and topographic data, combined with field work on appropriate terrestrial analogues, and mechanical experiments. Geographically, my research interests include both rocky objects in the inner Solar System and icy objects in the outer Solar System.
Inner Solar System:
Current interests in the inner Solar System include aeolian processes, specifically the origin of aeolian sand on Mars. Sand is wide-spread on Mars and the discovery of that this sand is in motion, which likely breaks it down, highlights the decades-old question as to the origin(s) of Martian sand. We’ve tested one hypothesis — the volcaniclastic hypothesis –in the Aeolis Dorsa region of Mars, and found it to be supported (Burr et al., 2022, Geology).
- Former MS student Ariana Boyd led some important first steps on this work as part of her thesis at the University of Tennessee.
An enduring interest is in fluvial (river-related) landscapes. Externally-funded fluvial research has included investigations of multi-billion-year-old fluvial deposits on Mars.
- Former Ph.D. student Dr. Robert Jacobsen provide the Mars community with a series of excellent insights, including a comprehensive mapping of these multi-billion-year-old fluvial deposits in the Aeolis Dorsa region of Mars.
- Dr. Jacobsen also analyzed the Martian deposits to more accurately derive paleodischarges
Field work on Earth, most effectively at the Quinn River in the Blackrock Desert of Utah, has provide insights for the Mars work.
- As a Ph.D. student with Prof. Alan Howard at the University of Virginia, Dr. Yo Matsubara led that multifaceted fieldwork.
- Dr. Jacobsen used the Quinn River to show howto more accurately derive paleodischarges and their implications for the Aeolis Dorsa region.
- With former research group members Dr. Robert Jacobsen, Dr. Alexandra Lefort, Rose Borden, and Dr. Samantha Peel, we have a USGS geologic map of the Aeolis Dorsa region in press, showing
Outer Solar System:
Although fluvial processes appear very rare in the Solar System, Titan, the largest moon of Saturn, affords us the opportunity to study on-going fluvial processes in liquid hydrocarbons.
- With work with former graduate students Sarah Drummond, Dr. Richard Cartwright and Dr. Ben Black, our analysis suggested that fluvial drainage on Titan were predominately rectangular.
Also in the outer Solar System, a primary area of investigation is tectonic processes on icy satellites. This work, begun at the Earth and Planetary Science Department at the University of Tennessee, substantially built on that department’s strengths in terrestrial tectonism and structural geology.:
- M.S. Student Ashley Dameron led a terrific paper creating, analyzing and interpreting topographic data of ridges on Europa.
- As a Ph.D. student, Dr. Chloe Beddingfield completed a series of excellent studies on outer Solar System satellites, specifically
- inferring listric faulting on Miranda and implications for ancient heat flow
- analyzing normal fault geometries across the Saturnian system and implications for viscous relaxation
- quantifying polygonal impact crater geometrics on Dione and so giving us new insight into tectonic structures outside the wispy terrain
Another interest is aeolian (wind-related) processes and landscapes. NASA-funded investigations include analysis of orbital images of wind-scoured landscapes on Mars and planetary wind-tunnel experiments to understand aeolian sediment transport on Titan. These experiments, which take place at the NASA Ames Research Center Planetary Aeolian Laboratory in Mountain View, CA, use a unique facility for which I led the refurbishment.
- Former postdoctoral associate Dr. Stephen Sutton and M.S. student Emily Nield were critical allies on this work. And Emily has a YouTube page that shows some of our high-speed videography from the Titan Wind Tunnel.
In addition to experimentally investigating aeolian processes on Titan, I also participate in experimental investigations into fluvial processes through using a cryogenic tumbler – the Titan Tumbler – to quantify the rounding and size-reduction rates of analog fluvial sediments for comparison to image data.
- This work consisted primarily of supporting Ph.D. graduate Tony Maue — please see Dr Maue’s webpage for details!
An area of research in the Astronomy and Planetary Science Department at Northern Arizona University is small bodies. My involvement in this area of planetary science includes organizing and participating in work to support NAU development of spacecraft mission concepts relevant to asteroid research. The indefinite deferral of the SIMPLEx mission call has put this work on the back burner, but we hope to pick it up again soon.