Permeability evolution in volcanic systems : field, laboratory, and numerical investigations

Overview & Synopsis

The permeability of various volcanic materials is an essential parameter governing the explosive behaviour of volcanic systems, as well as being important in many other scientific and industrial applications in environments where fluid flow is a major concern. Combining experimental rock deformation methods with field measurements, numerical modelling, and systematic analyses of rock microstructure, this work explores the complexities involved in the formation and destruction of porous networks in magma and volcanic rocks, addressing how permeability can evolve in volcanic systems. Competition between dilatant processes (which increase porosity) and compactant processes (which decrease porosity) influences the fluid transport properties both in the conduit-dwelling magma and in solidified edifice rock. These processes include (but are not limited to) vesiculation and bubble growth in the conduit, fracture and compaction of magma, post-emplacement thermal or mechanical fracturing, strain-induced deformation, and viscous sintering.