Instability of Magma Flow from Volatile-Dependent Viscosity

Oscillatory flow is recognized as a fundamental mode of behavior at silicic volcanoes, and understanding it allows improved short-term forecasting of timing and eruption style.

Abstract

Volatiles dissolved in silicic magma at depth exsolve as the magma nears the surface and cause an increase in viscosity of the magma. A model of a volcanic conduit within an elastic medium and a viscosity dependent on the volatile content of the magma produces oscillatory magma flow for a critical range of steady input flow rates. Oscillatory flow is recognized as a fundamental mode of behavior at silicic volcanoes, and understanding it allows improved short-term forecasting of timing and eruption style.