Shear forces drive explosive volcanic eruptions by creating gas bubbles in magma

Researchers have discovered that shear forces, not just pressure drops, cause gas bubbles to form in magma, explaining varied volcanic eruption styles. This new understanding suggests that even magma with low gas content can erupt explosively if shear forces create numerous bubbles, while high-gas magma might erupt gently if bubbles form early and release pressure. The findings, based on simulations and experiments, could lead to improved volcano hazard prediction models by incorporating the role of shear forces in magma conduits.