My research focuses on using geophysical tools to investigate the past and present of magma plumbing systems, and how these magmatic systems interact with tectonic faults and stresses, with implications for volcanic monitoring and hazard assessment. Recent advances in the field of volcanology have revealed the importance of looking at volcanoes as complex, laterally and vertically heterogeneous systems that span the crust, which can complicate the work of monitoring agencies who forecast volcanic activity. Additionally, advances in machine learning and high end computing allow us to analyze and visualize multiparametric data sets in heretofore unprecedented ways. As a PhD student at Cornell University, I analyzed actively deforming trans-crustal magma plumbing systems at two volcanoes in South America with InSAR time series analysis and gravity data analysis. My primary tools are InSAR (Interferometric Synthetic Aperture Radar), gravimetry, and geophysical inversion. While my focus is on geophysics, I constrain my analysis with other existing data from satellite remote sensing, other geophysical methods (including seismic and magnetotelluric), and petrology and geochemistry. My research emphasizes the importance of interdisciplinary study of complex volcanic systems in order to understand how magma moves in the subsurface, and how magmatic plumbing systems interact with local and regional tectonic stresses and faults, influencing cycles of seismicity and the evolution of volcanic systems over time.
My recent research at Sabancaya Volcano in Peru (JGR Solid Earth, 2020) is a clear demonstration of the value of interpreting InSAR surface deformation measurements with multiparameter, interdisciplinary constraints. Multiple strong seismic swarms preceded the reawakening of Sabancaya in 2013, prompting the question of whether the seismic activity was connected to the volcanic activity, and if so, how. My InSAR analysis revealed deformation from magmatic inflation offset >5 km from the summit, earthquakes, and long-lived fault creep. For the final published work I collaborated with multiple other InSAR and satellite remote sensing specialists as well as representatives of Peruvian volcano observatories to reveal how magmatic intrusions at Sabancaya in critically saturated crust precipitated the intense seismic activity through a fluid pressure pulse. Additionally, the offset magmatic inflation provided evidence of the lateral and vertical complexity of the magmatic system at Sabancaya, in which deep-seated mafic intrusion rejuvenated a shallower dacitic magma chamber, indirectly promoting eruption. This work has implications for understanding strong seismicity and offset inflation in other volcanic systems. This work shows the value of multiparameter, interdisciplinary research on inherently complicated volcanic systems.
In my first contribution to the scientific literature I showed how the magmatic plumbing system at Cerro Negro, Nicaragua, was unexpectedly connected at depth to a nieghbroing voclano, using a subsurface density model derived from an inversion of gravity data (MacQueen et al., 2016, Journal of Volcanological and Geothermal Research). I continued my investigation into the subsurface structure of volcanic systems in my PhD, adding InSAR as a tool for investigating actively deforming systems. In addition to the previously described work at Sabancaya, I am also currently using InSAR, gravimetry, cluster analysis, and eventually numerical modeling to interrogate several possible hypotheses to explain long-lived deformation at the dormant volcano Uturuncu in Bolivia, partially funded through a NASA “Future Investigators in NASA Earth and Space Science and Technology” (FINESST) grant. Although Uturuncu has not erupted in almost 250 ka, slow ( 2 cm/yr) deformation has been ongoing at this volcano for at least 50 years. My work at this system expands on existing geophysical data sets collected here and seeks to jointly interpret this rich dataset to determine whether we are observing rejuvenation of the magmatic system, the active formation of an ore body, or a ballooning diapir of magmatic mush. This work has direct implications for hazard analysis – volcanic inflation only sometimes precedes eruption, so distinguishing between pre-eruptive and non-eruptive volcanic deformation with complementary geophysical data is critical. This work also has the potential to inform economic geology as an unprecedented opportunity to observe the formation of an ore body in real time.
The value I place on interdisciplinary research stems in part from my experience working in industry. During my four years working at Micro-G LaCoste, I experienced first-hand the value of close collaboration between experts from different fields in the process of designing and troubleshooting gravity meters. While my focus was on geophysical analysis of test data, I had to communicate and work effectively with engineers, technicians, and clients ranging from industry geophysicists to academic physicists. While I gained many technical skills during this time, my key takeaway from this experience was the importance of knowing my own work well while also being able to communicate effectively with my colleagues. This is experience I bring with me to my academic research, and that I can bring into the classroom and in mentoring graduate students.
In future I plan to develop an externally funded research group for the study of subsurface volcanic structure using geophysical field and satellite data combined with modeling of this data in an interdisciplinary fieldwork. My group will actively collaborate across traditional boundaries within the geosciences, seeking active partnerships to investigate volcanic structure from all possible angles. In support of interdisciplinary geophysical research, I also hope to promote greater accessibility of gravimetry as a geophysical technique by working with existing agencies to establish a federally funded pool of gravity meters, similar to IRIS’s pool of seismic equipment.