IGP reported that during 11 and 20-21 February small- to moderate-sized lahars descended the El Volcán drainage, on the S flank of Huaynaputina, and traveled to within 500 m of Quinistaquillas, in the province of Sánchez Cerro, Moquegua region.

Geological Summary. Huaynaputina (whose name means "new volcano") is a relatively inconspicuous volcano that was the source of the largest historical eruption of South America in 1600 CE. It has no prominent topographic expression and lies within a 2.5-km-wide depression formed by edifice collapse and further excavated by glaciers within an older edifice of Tertiary-to-Pleistocene age. Three overlapping ash cones with craters up to 100 m deep were constructed during the 1600 CE eruption on the floor of the ancestral crater, whose outer flanks are heavily mantled by ash deposits from the 1600 eruption. This powerful fissure-fed eruption may have produced nearly 30 km3 of dacitic tephra, including pyroclastic flows and surges that traveled 13 km to the east and SE. Lahars reached the Pacific Ocean, 120 km away. The eruption caused substantial damage to the major cities of Arequipa and Moquengua, and regional economies took 150 years to fully recover.

Source: Instituto Geofísico del Perú (IGP)