- Volcanoes typically occur at plate boundaries (although they can also occur at hot spots). The occur at plate boundaries because these are place in the crust where magma can come to the surface.
- At a divergent plate boundary the plates pull apart. In between the plates magma can come to the surface and create a volcano. Volcanoes can occur at both divergent boundaries on land and divergent boundaries in the ocean floor.
- At convergent plate boundaries where subduction is occuring volcanoes can exist. As one plate is subducted beneath the other some of the rock will melt into magma and create volcanoes. This can happen where two oceanic plates collide (this creates and island arc) or where one continental and one oceanic plate collide.
- At hotspot mantle material has melted and risen near the surface where it can easily erupt as magma and form a volcano.
Convergent- Alaskan volcanoes, Indonesia (island arc), Phillipines
Diveregent- Seafloorspreading/mid-ocean ridges, volcaneos in the Great Rift Valley
Hot spot- Hawiian islands, Yellowstone