Revision 1

Accepted · first revision · record

Title: What decides whether an eruption is explosive or effusive?
Plain: The same volcano, with similar magma, can erupt explosively one time and quietly the next. The deciding factors seem to be how fast magma rises and how much gas escapes on the way up, but no model predicts the style beforehand.
Precise: For a given magma composition and volatile content, determine the conditions (ascent rate, conduit permeability and outgassing, crystallization, conduit geometry) that select explosive versus effusive eruption, and identify the observable precursors that discriminate them. An answer is a predictive model of eruption style verified against eruptions with known ascent conditions.
Settled by: Conduit models that, given monitored pre-eruptive gas fluxes, deformation and seismicity, correctly classify the style of a set of eruptions before they occur.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)