In situ X-ray tomographic microscopy observations of vesiculation of bubble-free and bubble-bearing magmas

Magma degassing is thought to play a major role in magma fractionation, transport, storage, and volcanic eruption dynamics. However, the conditions that determine when and how magma degassing operates prior to and during an erup- tion remain poorly constrained. We performed experiments to explore if the initial presence of gas bubbles in magma influ- ences the capability of gas to escape from the magma. Vesic- ulation of natural H2O-poor (<