A volcano is an opening in Earth’s crust that allows molten rock from beneath the crust to reach the surface. This molten rock is called magma when it is beneath the surface and lava when it erupts or flows from a volcano. Along with lava, volcanoes also release gases, ash, and rock. It’s a super hot mix that can be both incredibly destructive and creative.
Volcanoes form at the edges of Earth’s tectonic plates. These huge slabs of Earth’s crust travel atop the partly molten mantle, the layer beneath the crust. If you could see the plates, you might think they look like pieces of a puzzle because the edges fit together. But these puzzle pieces move, usually at the unnoticeable pace of only a few inches every year. Sometimes, though, plates collide with one another or pull apart, and it’s at these active zones where volcanoes form. Volcanoes may also erupt in areas called hot spots where the crust is thin. (Continue Reading from National Geographic)
Volcanoes are Earth's geologic architects. They've created more than 80 percent of our planet's surface, laying the foundation that has allowed life to thrive. Their explosive force crafts mountains as well as craters. Lava rivers spread into bleak landscapes. But as time ticks by, the elements break down these volcanic rocks, liberating nutrients from their stony prisons and creating remarkably fertile soils that have allowed civilizations to flourish. (Continue Reading from National Geographic)