Michael Manga, Department of Earth and Planetary Science
University of California, Berkeley
THE FLUID MECHANICS INSIDE A VOLCANO
Why do volcanoes only sometimes erupt explosively
ABSTRACT: The style and evolution of volcanic eruptions is dictated by the fluid mechanics that governs ascent of magma. Ascent in turn is influenced by the nucleation and growth of bubbles which provide the driving force for eruptions, the loss of gas from the magma, crystallization, fragmentation, and magma rheology. We integrate models of all these processes to show when each dominates and how they interact within a conduit. In particular, we show that ascent rate controls eruptive behavior: slowly ascending magmas erupt effusively and rapidly ascending magmas erupt explosively.