Colombia faces a second natural threat while continuing to assess the devastating consequences of the earthquake on August 10. The Puracé volcano, located in the department of Cauca, remains on orange alert after experiencing significant changes in its internal activity and chaining new emissions of ash and gases.
The temporal coincidence of both phenomena has generated concern and numerous speculations. However, the Colombian Geological Service (SGC) has clarified that the activity of the Puracé volcano was not caused by the earthquake. These are two independent geological processes, with different origins, depths, and locations.
The earthquake had its epicenter in the vicinity of San José del Palmar, in the department of Chocó, and originated at tens of kilometers deep. Volcanic activity, on the other hand, is concentrated beneath the crater of Puracé and other centers of the Los Coconucos volcanic chain, at generally depths of less than three kilometers.
The Puracé was already on alert before the earthquake
The reactivation of the volcano did not begin after the major quake. The SGC had been observing an increase in its activity since July 20 and decided to raise the alert level from yellow to orange on August 1, nine days before the earthquake.
The decision responded to the joint evolution of several indicators: the increase in the energy of the earthquakes located approximately one kilometer below the crater, the rise in the temperature of the emissions, the expulsion of sulfur dioxide, and the recurrent presence of columns of gas and ash.
These columns reached up to 3,400 meters above the summit of the volcano during the days of highest activity, according to information released by the Colombian scientific agency.
The orange level means that the Puracé presents significant changes in the monitored parameters and that the possibility of an eruption is significantly greater than during the yellow alert. However, it does not imply that a large magnitude eruption is certain or imminent.
Five new ash emissions
The latest extraordinary bulletin from the SGC confirmed that, from 2:00 PM on August 9 until the publication of the report the following day, five ash emissions had been recorded, with a maximum height of approximately 700 meters.
Some of them could be observed from the sidewalks of Cristales and Alto Anambío, belonging to the municipality of Puracé. One of the emissions was recorded at 10:34 hours on August 10 by the Mina camera, installed 2.2 kilometers north of the volcano.
The presence of ash also affected air transport. Authorities temporarily suspended operations at the Guillermo León Valencia airport in Popayán as a preventive measure against the risk that these particles represent for airplanes.
The SGC maintains the recommendation not to approach the craters of Puracé, Piocollo, and Curiquinga, where sudden emissions of gases or ash dangerous to the population may occur.
Can the Puracé volcano erupt?
Yes, there is a real possibility, but scientists cannot determine if an eruption will ultimately occur nor set a specific date. Since 2023, the Colombian volcanic alert system no longer links the orange level to a probable eruption within a specified period of days or weeks. The new classification recognizes that the probability exists in all active volcanoes, although it increases as one moves from green alert to yellow, orange, and red.
Volcanic activity can experience fluctuations. A temporary reduction in seismic activity or emissions does not necessarily mean that the risk has disappeared. To lower the alert level again, the SGC would need to observe a sustained trend towards stability over a sufficient period.
One of the most active volcanoes in Colombia
The Puracé is located approximately 27 kilometers southeast of Popayán and is part of Los Coconucos, a chain made up of fifteen volcanic centers.
It is a stratovolcano characterized by predominantly explosive activity. It has an outer crater of about 900 meters in diameter and an inner one of approximately 550 meters.
Its last eruption of considerable magnitude occurred in March 1977. Since 1827, at least fourteen other minor eruptions have been documented, some of which caused material damage and casualties, according to the records compiled by the SGC.
Due to this history and its proximity to populated areas, the Puracé is considered one of the most relevant active volcanoes in Colombia and is subject to permanent instrumental monitoring.
Colombia remains thus pending two different scenarios: the consequences and aftershocks of the devastating earthquake and the evolution of a volcano that continues to expel ash under close scientific monitoring.