Summary:
- Volcanoes are common along convergent and divergent plate boundaries.
- They are also found within lithospheric plates at hotspots.
- Most people think of volcanoes as large, peaky cones.
- But volcanoes can be large and broad, or tiny little cones.
- Volcanoes erupt because mantle rock melts.
- Magma can be created when temperature rises, pressure lowers, or water is added.
- Scientists question whether a volcano that is not erupting will ever erupt again and then describe it as active, dormant, or extinct.