Observatorio Vulcanológico y Sismológico de Popayán, Servicio Geologico Colombiano (SGC) reported that the number of both volcanic tremor (VT) and long-period (LP) seismic events at Puracé were stable during 7-13 May with only a slight increase in both the number and intensity of LP events on 9 May. The VT events had low magnitudes and were located at depths up to 4 km beneath the volcano and its E flank. The largest VT events were a M 1.8 recorded at 2351 on 7 May and at 2202 on 10 May. LP earthquakes were located in similar areas as the VT events, at depths less than 2 km. Earthquakes indicating magma movement were recorded during 7-9 May. Inclement weather sometimes prevented visual observations of emissions, though during the second part of the week diffuse fumarolic emissions from the crater and the crater rim were visible. Both carbon dioxide and sulfur dioxide emissions remained above baseline levels. The Alert Level remained at Orange (the second highest 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)