Eruption dynamics are governed by magma rheology.

The viscosity of silicate melts is influenced by composition, temperature, pressure, and dissolved water. However, the rheological properties of magmatic suspensions, which consist of crystals and bubbles suspended in the melt (three phases), are far less understood. Previous experiments have advanced our knowledge of two-phase systems (bubble + melt or crystals + melt), particularly in terms of how relative volume fractions, particle/bubble size distributions, and deformation rates affect their behavior.

At the University of Bristol, I collaborated with Dr Richard Brooker, Heidy Mader, and our in-house machine shop to conduct rheological measurements under high-pressure and high-temperature conditions. Direct measurements of hydrous melts at these conditions represent a significant advancement, and studying magma during decompression will provide a step-change in our understanding of the physical parameters that control conduit dynamics.

Keep watching this space…