I’m a 4th year PhD Candidate at the University of Oregon Department of Earth Sciences working with Dr. Paul Wallace. My research uses micro-scale features in minerals to understand macro-scale processes in volcanic systems.
For my dissertation, I’m analyzing tephra-forming eruptions from Nyiragongo and Nyamulagira volcanoes in the East African Rift. This project is part of a broader NSF-funded effort to chemically constrain volcanic hazards in the Virunga Volcanic Province. My research employs a broad swath of analytical methods, from X-ray tomography to stable isotope geochemistry, to answer questions like…
Where are magmas stored in the crust?
How long do they reside there prior to eruptions?
How fast do they ascend to the surface?
Why do some volcanoes emit more greenhouse gases than others?
During my PhD I’ve developed a keen interest in numerical modeling, statistics, and geospatial analysis, and am always looking to branch out and learn new skills.
Research
Investigating magma storage histories using melt inclusions
Melt inclusions–tiny blebs of liquid entrapped in crystals–can provide insightful snapshots of the chemical and physical conditions of magma bodies at depth. These micrometer-scale features can retain signatures of magmatic volatiles (H2O, CO2, S, etc.), which can influence surficial gas emissions and eruptive style. We can use the concentration of volatiles in melt inclusions to estimate the pressure, and subsequently, depth at which inclusions are entrapped, providing insights into magma plumbing systems.
Currently, I am studying melt inclusions from tephras erupted along the flanks of Nyiragongo and Nyamulagira, two highly active volcanoes in the East African Rift System (EARS). These volcanoes produce some of the most volatile-rich magmas on earth, but little is known about how they form. By measuring the volatile, major element, trace element, and isotopic characteristics of inclusions, we are reaching an improved understanding of how these magmas form, and what kinds of hazards they can produce.
Estimating magma storage timescales using diffusion in minerals
The chemistry of minerals crystallizing from magma depends on temperature, pressure, and bulk composition. If these conditions are perturbed, for example, if a hotter magma is injected into the system–minerals will kinetically reequilibrate to the new conditions. As this process is time-dependent, we can capitalize on this process to estimate the timescales between magma perturbations and eruptions.
To understand the timescales between eruptions and their potential triggers, I’m measuring compositional gradients in olivine phenocrysts. Through numerical models, I’m making estimates of how long it takes to generate these gradients. As these timescales are often associated with seismic and geodetic signals of unrest at volcanoes, these timescale calculations can provide beneficial information to government officials.
Using volatiles in anhydrous minerals to calculate magma decompression rates
Nominally anhydrous minerals, like olivine and clinopyroxene, all contain trace amounts of water, which is typically proportional to the total amount of water dissolved in the magma. As magmas decompress on their way to the surface, water solubility decreases, leading to disequilibrium, causing water in the mineral to diffuse back into the melt. As with diffusion of major elements in crystals, we can capitalize on this kinetic process to estimate the timescales at which magmas ascend to the surface.
I’m measuring hydrogen species in olivine using Fourier-Transform Spectroscopy (FTIR) to investigate the rate of decompression of magmas at Nyiragongo and Nyamulagira.
Apatite as a monitor of magma evolution
Apatite, a calcium phosphate mineral, is a common accessory phase in many volcanic rocks. Its ability to incorporate volatile species in its chemical structure makes it a valuable tool for fingerprinting the volatile components of magmas. With the ability to incorporate sulfur at multiple valence states (S6+ and S2-), the mineral apatite also serves as an excellent probe of magma oxidation state.
For my undergraduate thesis at Lafayette College, I analyzed apatite phenocrysts from Torfajökull Central Volcano, a rhyolitic center along Iceland’s propagating rift. We found that for one eruption, elevated S contents in apatite indicated a shift towards more oxidizing conditions, likely correlating with degassing. To learn more about our work, checkout our AGU Monograph Chapter.
