How do volcanoes form?

Volcanoes are typically formed when the tectonic plates go against each other, causing the earth to heat and melts rock into magma and gases. The magma will be stored in chambers near the surface. Volcanoes can also form by the tectonic plates moving away from each other. In this case, magma will push up and form lava although it won't reach the surface. Instead, the volcano will be found on the ocean floor.

Sometimes volcanoes aren't even formed by the tensions in tectonic plates, but by hotspots. Hotspots are places where the mantle heats up, causing magma to bubble and move to the surface. It is widely believed by scientists that these volcanoes are formed by columns called mantles plumes.