Volcanoes
Volcanoes are openings in Earth's crust that allow molten rock, gases, and ash to escape from beneath the surface, playing a key role in shaping the planet's geology and, historically, human civilization.
Most volcanoes form along boundaries where tectonic plates meet, either where plates collide and one is forced beneath another or where plates pull apart, allowing magma from Earth's mantle to rise to the surface.
Volcanic eruptions range from relatively gentle lava flows to catastrophic explosive eruptions capable of altering global climate temporarily by releasing large amounts of ash and sulfur dioxide into the atmosphere.
While volcanic eruptions can be devastating, volcanic activity has also historically enriched soil for agriculture and created some of the most fertile farmland in the world, from Indonesia to Italy.