Hydrovolcanic Explosions: The Systematics of Water-Pyroclast Equilibration

Abstract
The initial contact of external water with erupting magma and the mass ratio of water to magma govern the development of hydrovolcanic phenomena. The phase relations of water within the runout system and the separation of vapor or liquid from the pyroclasts explain gradational transitions between some pyroclastic flows, base surges, mud hurricanes, mudflows, and sheetfloods.