Global Volcanism Program | Image GVP-08623
The 50-m-deep central crater (seen here looking NE toward the breach in the large summit depression) and the SW crater were the site in 1866 of the last and largest historical eruption of Turrialba volcano. Phreatomagmatic eruptions in January and February produced ashfall in Costa Rica's Central Valley for four days in January and three days in February. Ash fell as far as Puntarenas and El Realejo in Nicaragua. Pyroclastic surges traveled more than 4 km, and small lahars traveled down the Río Aquiares and presumably other valleys.
Photo by José Enrique Valverde Sanabria, 1996 (courtesy of Eduardo Malavassi, OVSICORI-UNA).