From Magma to Tephra: Modelling Physical Processes of Explosive Volcanit Eruptions (Developments in Volcanology)

Hot magma rising through the Earth's crust releases gases that expand and may come into contact with external water that vaporizes. The magma is then fragmented into an accelerating gas-particle/droplet mixture that is shot into the atmosphere, possibly in an overpressured state, where it may buoyantly rise up into the stratosphere as an ash plume, partially through totally collapse back to the surface, or rapidly expand sideways,or perform a combination to these processes. Tephra is then deposited on the Earth's surface by pyroclastic fall, flow or surge, or some hybrid mechanism. The combination of processes that operate from the degassing of magma to the emplacement of tephra makes an explosive volcanic eruption, and the physical characterization of these processes is the scope of this book. This text reviews basic physics and summarizes recent physical modelling advances of processes operating during explosive volcanic eruptions. The book addresses topics such as: magma degassing; magmatic and phreatomagmatic fragmentation; flow in the conduit; eruption column dynamics; transport and emplacement processes of pyroclastic fall, flow and surge.