DLESE description of Deadly Lahars from Nevado del Ruiz, Colombia: November 13, 1985

This web site describes a series of Lahars that occurred from the Nevado del Ruiz volcano in the Andes mountains, the northernmost and highest volcano in Colombia. Beginning in November 1984, the volcano began showing clear signs of unrest. An explosive eruption from Ruiz's summit crater on November 13, 1985, at 9:08 p.m. generated an eruption column and sent a series of pyroclastic flows and surges across the volcano's summit. Within minutes, pumice and ash began to fall to the northeast along with heavy rain that had started earlier in the day. Within four hours, lahars had traveled 100 km and left behind a wake of destruction: more than 23,000 people killed, about 5,000 injured, and more than 5,000 homes destroyed along the Chinchina, Guali, and Lagunillas rivers and destroying the town of Armero, Columbia. This deadly eruption of Nevado del Ruiz offers lessons on the generation of lahars for scientists, emergency-response professionals, and communities located downstream of such ice- and snow-covered volcanoes. The narrative is illustrated with 9 photographs.