Synopsis

Volcanoes are mountains born of molten rock. The Earth's crust is structured as large, shifting plates, perpetually in slow motion. These plates rest upon the mantle, a layer of hot rock that flows with a viscous quality, like thick syrup. Within the mantle, pockets of rock reach intense heat and approach a liquid state, becoming magma. Occasionally, this magma forces its way to the surface, coalescing into a volcano.