Near Surface Geophysics
I specialize in applying geophysical techniques, notably ground penetrating radar, resistivity, magnetics, and gravity, to the investigation of volcanological deposits and processes. In addition to volcanological investigations, I also use these tools to examine a variety of geologic and/or environmental hazards, including sink holes, damaged wetlands, ground contamination, archaeological cites, and cemeteries. In each of these studies, and in archaeology in particular, geophysics can provide valuable information about the location and extent of features that could not otherwise be gleaned without risking the destruction of the local environment and/or the object under study.
I use field, laboratory, and numerical experiments to determine the ways that volcanic ash moves through the atmosphere. Current experiments are focused on tephra aggregation, specifically the rate at which particles aggregate in subzero conditions, and how this rate is related to the charges of the aggregating particles. Ultimately, these experiments will enable the determination of aggregation rates which can be plugged into hazard models used to predict both the mass density of tephra within the atmosphere and the mass loading of tephra on the ground. These models are important as they are useful both for aviation safety and for hazard mitigation.
Volcanic Bombs and Blocks
Volcanic bombs and blocks are particles 6 cm in diameter or greater ejected from volcanoes during explosive eruptions. Historically, these particles are typically considered to follow ballistic trajectories before coming to rest on the ground. However, these pyroclasts can also collide mid-air, resulting in significant deviations from truly ‘ballistic’ flight paths. By developing a numerical model capable of accounting for these particle-particle interactions, I am able to explore the range of scenarios documented by high-speed imaging of volcanic eruptions. This enables the quantification of the effects of pyroclast-pyroclast interactions during explosive volcanic activity.
I am also interested in modeling the cooling of pyroclasts in-flight, especially as it relates to the kinematic properties of blocks (e.g. restitution coefficient, spring constant, friction coefficient, etc).
Scoria Cone Morphology
The volcanic processes that produce scoria cones, often considered the simplest of volcanic constructs, can in fact vary by orders of magnitude in explosivity. As the hazards related to Hawaiian eruptions differ from those associated with, for example, violent Strombolian activity, it is important to characterizee the formation mechanism(s) responsible for cone construction. To this end, I investigate scoria cone morphology based on surface and exposure surfaces, while also employing ground penetrating radar in order to generate a three-dimensional view of the processes responsible for constructing the outer 10+m of scoria cone deposits. Radar has also proven to be a useful tool in the study of tephra deposits, which are often associated with scoria cones, as well as with the deposits of larger eruptions.
Cyberinfrastructure in Volcanology
Vhub.org is an online resource for collaboration in volcanology research and risk mitigation. As a member of the Vhub development team, I work actively on model and resource development, with particular emphasis on tephra modeling, graphical user interface development, and educational resources. Additionally, I take a leadership role in the development and implementation of training workshops that aim to introduce Vhub.org to the volcanological community. My workshop specializations include tephra modeling, online tool development, vhub groups, and general vhub use.
My interest in geoscience education is focused primarily on how to use geoscience to instill in students both quantitative and model literacy. The prevalence of computational models in a multitude of fields and industries necessitates an understanding of concepts like model verification, validation, and uncertainty. By developing educational resources focused on quantitative skills-building and model literacy, I aim to increase both quantitative and model literacy among students.
One of my underlying goals in geoscience education is to find ways to bring active scientific research into the classroom environment in meaningful ways. This includes using student interest in open research questions to help grow their scientific skills-set, providing motivated students with projects that they can take ownership of and present at scientific meetings, and familiarizing students with the the scientific method and the academic and industrial pathways and partnerships that enable research to be undertaken and results disseminated.