Global Volcanism Program | Image GVP-09390
A dense ash plume pours from the summit crater of Irazú volcano on April 14, 1964, about midway through a major explosive eruption that began in 1963. The ash-covered plateau at the left is Playa Hermosa, a buried older crater. The road to the summit of Irazú can be seen at the lower left. Heavy ashfall from the 1963-65 eruption blanketed the Central Valley and caused major economic disruption. The eruption merged several pre-existing smaller craters and increased the diameter of the vent to form the larger present-day crater.
Photo by U.S. Geological Survey, 1964.