A volcano is a rupture on the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle.
Volcanoes consists of
- Magma chamber: A large underground pool of molten rock found beneath the surface of the Earth.
- Lava: Hot molten magma when it reaches the surface.
- Pyroclastic Flow – Pyroclastic flows are fast moving currents of hot gas and rock with travel downhill from a volcano, reaching speeds of 700 km/hour. The gas can reach temperatures of more than 1,000 degrees C, and is one of the greatest dangers from volcanic eruptions.
- Vent: An opening which allows hot magma, ash and gases to escape.
- Crater: A bowl-shaped opening at the top of a volcano
- Ash cloud: Clouds of steam, gases and hot ash that is spewed out from a volcanic eruption.
- Volcanic bombs: A mass of molten rock that are ejected during a volcanic eruption.
- Secondary Vent – On large volcanoes, magma will reach the surface through several different vents, and not just the main vent. This can form cones, eject lava, and cause destruction.
- Secondary Cone – Secondary cones build up around secondary vents on larger volcanoes.