Global Volcanism Program | Image GVP-04279
A dark ash plume at Arenal rises above white atmospheric clouds in 1968. A major explosive eruption began on 29 July 1968 from three new craters down the western flank. A series of major explosions took place between the morning of 29 July and the afternoon of 31 July.
Photo by Tom Simkin, 1968 (Smithsonian Institution).
This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.