In this USGS video, lava forms a “dome fountain” at the inlet to the lava lake in Halema’uma’u crater on Jan. 2-3, 2021, in Hawaii Volcanoes National Park.
In the video, lava from the western vent cascades beneath roofed vertical channels to enter the lava lake at an inlet that has become partially submerged. The result is a rolling upwelling of lava near the inlet called a “dome fountain.”
Dome fountains have been observed during eruptions at Mauna Ulu and Pu‘u ‘O‘o. Dome fountains can occur when lava rapidly emerges from a constricted vent or fissure onto the surface or, as in this case, beneath the surface of a lava lake. The feature resembles, in part, a bubbling water fountain. The height of the dome fountain was estimated to be about 16 feet with an estimated width of 33 feet.