A new model of volatile bubble growth in a magmatic system: Isobaric case

• Published in: Journal of Geophysical Research: Solid Earth 2007-12, Vol.112 (B12), p.n/a
• Main Author: L'Heureux, Ivan
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; physical volcanology; theory of bubble growth; volatile in magmatic systems
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/2006JB004872

The nucleation, growth, and, ultimately, coalescence of volatile bubbles in a silicate melt (magma chamber) play a crucial role in the processes leading to volcanic eruptions. A new diffusion‐limited nonlinear growth and nucleation model of volatile bubbles in such a system is proposed here. In contrast to previously existing models, the present one treats the competitive effects of the other randomly located bubbles on the growth dynamics in presence of a hydrodynamic coupling with the melt advection field through its viscous resistance. I consider here cases where the fluid pressure is kept constant. Numerical results pertaining to a basaltic and a rhyolitic melt suggest that for small volatile supersaturations and for small times, bubble growth occurs essentially as in the single‐bubble problem. However, for longer times, the influence of the other bubbles is important. I find that bubble growth rate decreases exponentially with time and propose an approximate expression for the decay rate. Finally, for larger volatile supersaturations, the bubble growth is subjected to transitions to and from an inflationary regime, whereby the bubble radius increases very rapidly during a small time interval.