Magmatic Processes
Magmatic systems are a key pathway connecting the deep Earth to the climate and the biosphere. The spatio-temporal scale of magma transport in the crust and the lithosphere sets the rate of volcanic eruptions and controls volcanic gas fluxes, hydrothermal activity, and crustal density and rheology. Consequently, my research focuses on two key questions: What are the primary processes controlling magma transport from source (melt generation) to eruption, and associated timescales? How do these change in different tectonic environments?
I create coupled models and combine them with observations to greatly increase our understanding of magma transport in the asthenosphere (melt channelization in plume-ridge systems, Mittal & Richards 2017), lithosphere (fracture-mechanics and analog dike experiments, Mittal & Richards 2018), and the crust (multiply connected thermo-mechanical magma chambers, Mittal & Richards 2020b; data-driven parameterizations of high-velocity fault friction, Saltiel, Mittal, et al., 2020).
I developed a new thermo-mechanical model for magma reservoirs interacting with crustal hydrothermal systems. Using this framework, I demonstrated for the first time that non-eruptive magmatic gas emissions strongly affect the likelihood of an eruption [Mittal & Richards, 2019]. In collaboration with a geochemist, I created a new petrological method to determine eruption initiation timescales and used it to show that both mafic and silicic systems can be primed for eruption on similar time periods, contrary to previous assumptions [Antonelli, Mittal 2019].
Using the Deccan Traps as an archetype for CFB systems, I created an extensive data compilation, comprising geochronology, paleomagnetism, geochemistry, volcanology (lava flows, eruptive vents), and geophysics (seismic, gravity, magnetotelluric) [Mittal & Richards 2020a]. Integrating this compilation with my magmatic model toolkit, I definitively showed that the conventional model of one/a few large magma chambers cannot explain the frequent, large individual CFB eruptions. Instead, CFBs have a trans-crustal magmatic system with multiple smaller (∼ 102 - 103.5 km3) magma bodies that stochastically connect to feed eruptions [Mittal & Richards 2020b].