This module aims to provide you with knowledge of volcanoes and volcanic systems. Its foundations are an understanding of the properties and behaviour of volcanic materials gained through laboratory, theoretical and field study. The module emphasizes the widely-applicable physical and chemical processes that occur during volcanic activity, including variations in solubility, rheology, phase, density and permeability. The interaction of volcanic processes with the biosphere, atmosphere and hydrosphere are discussed. The products of volcanism, together with the hazard and benefits to life on Earth are studied.