Global Volcanism Program | Image GVP-08885
An avalanche produced during an 8 December 1994 phreatic explosion at Irazú traveled down the Río Sucio to the north, destroying trees high up the banks of the river. Associated lahars swept many kilometers farther down the river, which flows through the Cordillera Volcánica Central Forest Reserve. The explosion formed a new crater in a geothermal area north of the main crater.
Photo by Jorge Barquero, 1998 (OVSICORI-UNA).