Intraplate volcanism: Intraplate regions of voluminous volcanism are called hotspots.
Ring of fire: The Ring of Fire is an area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean.
Lava: magma that flows onto earth's surface; the rock that forms when lava colls and solidifies.
Magma: Liquid rock produced under earth's surface.
Viscosity: the state of being thick, sticky, and semifluid in consistency, due to internal friction.
Silica Content: Silica means Silicon Dioxide (SiO2) that molten rock, that is lava, contains as it is thrown out / ejected from volcanoes.