 Lava fountain of the Pu`u `O`o cinder and spatter cone on Kilauea Volcano, Hawaii. |
Lava fountain
A jet of lava sprayed into the air by the rapid formation and expansion of gas bubbles in the molten rock is called a lava fountain. Lava fountains typically range from about 10 to 100 m in height, but occasionally reach more than 500 m. Lava fountains erupt from isolated vents, along fissures , within active lava lakes , and from a lava tube when water gains access to the tube in a confined space (see type of explosive activity where lava enters the sea , from the USGS Hawaiian Volcano Observatory). |
 Dome fountain about 20 m tall formed during the 1969-71 Mauna Ulu eruption of Kilauea Volcano, Hawaii. |
Dome fountain Dome fountains are hemispherically shaped lava fountains that form when the upward pressure of magma from the conduit below is in approximate equilibrium with the mass of ponded lava through which it passes. Dome fountains may reach as high as several tens of meters, and they typically occur in relatively gas-poor lavas. |
 Arching lava fountain 10-15 m tall on the east rift zone of Kilauea Volcano, Hawaii. |
Arching fountain Instead of shooting lava vertically from a vent, an arching lava fountain sends lava upward and outward. Arching fountains form when the shape or geometry of an erupting vent forces the lava outward in a continuous stream of airborne lava. |
