Volcanoes - A vent or fissure in the Earth's surface through which magma and gases are expelled.

Ring of Fire - A volcanic belt formed by the many volcanoes that rim the Pacific Ocean.

Subduction Zone - A place where old oceanic crust is forced back down into an ocean trench.

Magma chamber - An underground pocket of molten rock.

Vent - A Volcanic opening from which lava flows.

Plate boundary - A place where two plates meet.

Proclastic flow - The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption.

Fumarole – An opening in Earth’s crust, often found close to volcanoes, which gives off steam and gases.