Observatorio Vulcanológico y Sismológico de Popayán, Servicio Geologico Colombiano (SGC) reported increased unrest at Puracé on 5 January. A sudden increase in carbon dioxide emissions was detected during the morning and decreased through the day; increased gas emissions were visible in webcam images during the afternoon. Seismicity increased at 1450 and continued at high levels at least through 1715, the time the report was issued. The earthquake signals indicated fluid movement, had low magnitudes, and were located less than 2 km below the summit. The Alert Level remained at Yellow (the second 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)