Non‐Newtonian viscosity of basaltic magma

Abstract

Basaltic melt drives most of earth's volcanism. Understanding its rheology is crucial for any model of magma transport and volcanic eruption. Basaltic magma is generally treated as a quasi Newtonian liquid, but there are observations of Non‐Newtonian behaviour. With a method, that allows measurement of Non‐Newtonian viscosity of a representative melt (molten basaltic rock), we found a strong shear rate dependency of viscosity in a wide range of temperatures. The temperature‐viscosity dependency indicates properties of the molten phase as the cause. The viscosity data are in good agreement with a power law model.