Cotopaxi eruption causes deadly mudflows in Ecuador

Background. Cotopaxi is an active stratovolcano in the Andes Mountains, located in Cotopaxi National Park, about 50 km south of Quito. It is one of Ecuador's most active volcanoes, known for 87 eruptions that created numerous valleys formed by lahars. The main danger of significant eruptions is the flash-melting of its summit glacier, resulting in devastating lahars guided by river valleys.

Lahar Formation. Lahars are extremely destructive and deadly, capable of flowing tens of meters per second and reaching depths of up to 140 meters. Large flows destroy any structures in their path. During the 1877 eruption, pyroclastic flows descended on all sides of the mountain, melting the entire ice cap. This process generated lahars that traveled more than 100 km into the Pacific Ocean and western Amazon basin.

Destruction and Casualties. The 1877 eruption is listed among Cotopaxi's most violent historical events. The regional capital Latacunga, located in the south valley, was destroyed by lahars caused by volcanic activity. The event wiped out surrounding cities and valleys. The great distances traveled by these significant lahars greatly increased the hazard areas to include all river valleys leading from the volcano.