Global Volcanism Program | Image GVP-08885
An avalanche produced during a December 8, 1994 phreatic explosion swept 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 cuts through lush valleys of the Cordillera Volcánica Central Forest Reserve. The explosion formed a new crater in a fumarolic area north of Irazú's main crater.
Photo by Jorge Barquero, 1998 (OVSICORI-UNA).