Global Volcanism Program | Image GVP-01030
A submarine eruption from Anak Krakatau on 13 June 1930, produces both a vertical eruption plume and a base surge extending radially from the vent along the surface of the sea. Submarine eruptions were first observed in December 1927, forming several ephemeral islands. By 12 August 1930 Anak Krakatau had become a permanent island.
Photo by W. Petroschevsky, 1930 (courtesy Volcanological Survey of Indonesia).