Global Volcanism Program | Image GVP-03463
A dome fountain reached heights of about 20 m for hours on 11 October 1969. This unusual activity, produced by fountaining from a circular, vertical conduit at relatively constant gas pressures, occurred early during the Mauna Ulu eruption. This East Rift Zone eruption lasted from 1969 until 1974.
Photo by Jeffrey Judd, 1969 (U.S. Geological Survey).