Magmatic volatiles and degassing from the Earth

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This proposal examines the nature, origin, and transport of magmatic volatile elements in influencing and controlling volcanic activity, especially the style and size of violent explosive eruptions which pose a major threat to millions of people worldwide. My goal is to use a series of new and novel tools and approaches which together will propel our understanding of how, when, and why volcanoes erupt. The research is designed to examine volatiles through a vertical section of the shallow Earth system, moving from crustal conditions where volatiles are stored and transported upward, through the near surface where magmatic volatiles interact with shallow groundwater and hydrothermal systems, to the surface where the volatiles emerge as volcanic gas. The first component of the research will use nominally anhydrous minerals (NAM's), which contain small amounts of water, to understand the behaviour of magmatic water in the shallow crust, including its accumulation and loss (degassing). Two systems will be studied in detail, one basaltic (Stromboli, Italy) and one silicic (Toledo caldera, New Mexico, USA). The second component of the research is to understand phreatic eruptions, which are commonly driven by inputs of magmatic gas into shallow hydrothermal systems. I will design, build, and use a new CH4-CO2-H2S MultiGas instrument (first of its kind) to measure the CH4/CO2 gas ratio, which provides a monitor of hydrothermal and magmatic interactions. I will also conduct a field experiment at Rincn de la Vieja volcano in Costa Rica, where phreatic eruptions are common. I will conduct a series of real-time gas, seismic, and deformation measurements before during, and after phreatic eruptions. Last, I will study a suite of hydrothermal breccias at Turrialba volcano, Costa Rica, to determine the nature of sealing and unsealing processes associated with phreatic eruptions and the underlying magmatic-hydrothermal system. The final component of this research is to characterize volcanic plumes isotopically on a near real-time basis, to evaluate spatial and temporal changes in relation to eruptions. The isotopic systems include 13C in CO2, 13C in CH4, and D and 18O in water. In terms of highly qualified personnel (HQP), I will train a total of 13 students (6 MSc-PhD-PDF and 7 BSc). In terms of equity, diversity, and inclusion (EDI), gender balance for my students over the past six year has been 56% male and 44% female, and currently it is 43% male and 57% female, with two students from other under-represented groups. My EDI efforts include maintaining gender balance, targeted recruiting, and outreach.