Bubble Formation in Magma

Volcanic eruptions are driven by bubbles that form when volatile species exsolve from magma. The conditions under which depend mainly on magma composition, concentration, presence of crystals, and decompression rate. These all predicated the mechanism volatiles melt to bubbles. We critically review known or inferred mechanisms bubble formation in magmas: homogeneous nucleation, heterogeneous nucleation crystal surfaces, spontaneous phase separation (spinodal decomposition). propose a general approach for calculating rates as sum contributions suggesting may not be limited single prior eruption. identify three major challenges further experimental, analytical, theoretical work is required permit development model natural eruption conditions. ? summarize various understood operate. Bubble evolve throughout ascent change such simultaneously sequentially via more than one mechanism. Contributions both multiphase phases can captured equation. Future should focus constraining macroscopic surface tension, characterizing microphysics, developing framework modeling formation, mechanisms, over pathways.