High Temperature Reactions Between Gases and Ash Particles in Volcanic Eruption Plumes

The common manifestation of an explosive volcanic eruption is the emission of a hot mixture of solid fragments and expanding magmatic gases, referred to as the eruption plume, into the atmosphere (Fig. 1, Sparks et al. 1997; Carey and Bursik 2015). Ash (the rock particles less than two millimeters across) usually dominates the plume’s solid load, whereas water vapor followed by CO₂ and lesser amounts of sulfur and halogen species constitute the eruptive gas phase. Plumes can initially travel as a jet with velocities up to 600 m s⁻¹, temperatures above 800 °C...