Global Volcanism Program | Image GVP-04251
Three craters formed from the summit to the lower west flank of Arenal during the initial stages of a long-lived eruption that began on 29 July 1968. The lowermost crater (Crater A) is the near the center of this photo. Crater B is between Crater A and Crater C, which is producing a gas plume near the summit. Crater A was the source of the largest explosions, pyroclastic flows, and ballistic ejecta.
Photo by William Melson, 1968 (Smithsonian Institution).
This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.