Las Pilas is a complex volcano like Vesuvius. Little is known about its first historical eruption in ca. 1528. Small phreatic eruptions occurred in 1952 and 1954. Neither eruption caused any damage. This photo was taken on October 23, 1952, and shows steam escaping from a fissure at Las Pilas. Photograph credit: Howell Williams. Photo courtesy of NOAA'S National Geophysical Data Center.
Sources of Information:
McBirney, A.E., 1955, Thuoghts on the eruption of the Nicaraguan volcano Las Pilas: Bull Volc., v. 17, p. 113-118.
Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.