The Servicio Geologico Colombiano (SGC) reported that seismic tremor at Puracé increased at 2356 on 19 January with events located in the NW part of the Los Coconucos volcanic chain. An ash emission rose 1.4 km above the Curiquinga crater rim and drifted SW, causing a notable sulfur odor in the towns of Puracé (11 km NW) and Coconuco (12 km WNW), along with ashfall in Coconuco, Timbío (34 km WNW), Popayán (30 km NW), and Sotará (23 km W). The emission was detected by pressure sensors, was visible in webcam images, and was observed by nearby residents. A significant increase in sulfur dioxide emissions was detected in satellite data and from instruments at the summit. Deformation was also detected at the Puracé and Curiquinga craters. On 20 January SGC noted that four vents producing gas emissions had been identified based on webcam images and reports by residents: two at Puracé and two new vents in Curiquinga. The Alert Level remained at Yellow (the second lowest level on a four-color scale).

Geological Summary. Puracé in Colombia consists of an andesitic stratovolcano with a 500-m-wide summit crater constructed over a dacitic shield volcano. It lies at the NW end of a volcanic massif opposite Pan de Azúcar stratovolcano, 6 km SE. A NW-SE-trending group of seven cones and craters, Los Coconucos, lies between the two larger edifices. Frequent explosive eruptions in the 19th and 20th centuries have modified the morphology of the summit crater. The largest eruptions occurred in 1849, 1869, and 1885.

Source: Servicio Geológico Colombiano (SGC)