This 12 April 1940 photo shows a lava fountain within the Mauna Loa Moku‘āweoweo caldera from the SE. The eruption began during the night of 7 April from fissures that soon migrated down the SW rift zone. A 6-km-long fissure produced lava flows that covered two-thirds of the caldera floor. The eruption lasted until 18 August.

Photo by G.O. Fagerlund (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Galleries: Volcanic Gases | Lava Flows | Fissure Vents

Keywords: gas | plume | fissure | lava | lava flow | lava | cone | crust | spatter cone | lava fountain | emissions | caldera | eruption

Mauna Loa