Global Volcanism Program | Image GVP-11683
An ash plume rises above Cerro Negro on July 24, 1947. A strong explosive eruption beginning on July 9 produced ashfall that damaged crops at Malpaisillo and prompted evacuations of towns west of the volcano. Ash fell to the Pacific coast and to 7 inches on the roof of the cathedral at Leon. A NE-flank parasitic cone was formed and lava flows were emitted from both summit and flank vents. The eruption lasted until August 2, 1947.
Photo by Ray Wilcox, 1947 (U.S. Geological Survey).