Ash and lava form the layers that shape the volcano over time.
geyser
Hot water spring that ejects sporadic jets of water and vapor.
lava flow
Lava mass pouring from a volcano at average speeds of 300 meters per hour; it can reach temperatures as high as 1,200°C.
fumarole
Regular emission of gas from a fissure on the Earth’s surface.
sill
Layer of magma that has solidified between the layers of the Earth’s crust; it is about 10 meters thick and several kilometers long.
dike
Mass of magma that enters the Earth’s crust and then solidifies in the form of bladelike shafts that are vertical or oblique to the layers of the Earth.
magma
Molten rock and gas under very high pressure that can reach extremely high temperatures.
magma chamber
Pocket where magma accumulates before rising to the surface.