Global Volcanism Program | Image GVP-04302
Steam rises in June 1956 from a new circular sub-crater formed in the summit crater of Poás volcano during an eruption from 1952-57. Phreatic explosions increased in intensity from 1952 to early 1953. Ash emission began in May 1953, and the crater lake was vaporized by May 22. The first juvenile material was observed in mid July, and strombolian activity continued until 1955, after which geyser-like activity resumed. Slabs of lava appeared in the crater in 1957, and a phreatic explosion on December 25, 1957 ejected ash.
Photo courtesy of Jorge Barquero (Universidad Nacional Costa Rica), 1956.