A scaling for the permeability of loose magma mush validated using X-ray computed tomography of packed confectionary in 3D and estimation methods from 2D crystal shapes

Magma chambers in the Earth are ‘mushy’, meaning that liquid magma is trapped in between solid crystals. In many cases, the liquid magma must escape before an eruption occurs. For the liquid magma to escape, it must move through the tight spaces between the solid crystals, which occurs at a speed dictated by the ‘permeability’ of the crystal framework. Here, we use fudge and sugar crystals as a proxy for the solid crystals in these magma chambers, and we use simulations to observe how the fluid between the fudge and sugar moves. The key advance here is that we show how the complicated shape of fudge and sugar crystals changes the speed at which the fluid is able to move.