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).