The phenomena associated with volcanic activity WordNet 3.0 & Open English WordNet

Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a vent. Wikipedia

Phenomena and processes associated with the action of volcanos, geysers and fumaroles Wikidata

The processes by which magma and its associated gases rise into the crust and are extruded onto the Earth's surface and into the atmosphere. OmegaWiki