Purace Volcano in Colombia Reaches Phase of Highest Probability of Eruptive Activity

The National Unit for Disaster Risk Management (UNGRD) raised the alert level for the Purace Volcano, in the department of Cauca, southwestern Colombia, to orange, indicating a higher probability of eruptive activity, and activated the National Crisis Room.

Since July 20, the Los Coconucos volcanic chain, of which Purace is part, has been recording a continuous increase in activity. However, in recent hours, the Colombian Geological Service (SGC) reported significant changes in the behavior of Purace.

Purace Volcano is one of the 25 active volcanic structures monitored by the SGC. It is located 27 km southeast of Popayan and is one of the fifteen volcanoes that make up the Los Coconucos Volcanic Chain (CVLC). It is characterized as a stratovolcano with predominantly explosive activity and has two craters: an outer crater measuring 900 meters in diameter and an inner crater measuring 550 meters in diameter.

Its last eruption of considerable magnitude occurred in March 1977, and since 1827 at least 14 smaller eruptions have been documented that caused material damage and loss of life. For this reason, it is considered one of the country’s most active volcanoes.

Residents urged to stay away from the crater areas

In recent days, several of the parameters monitored by experts at the volcano have increased, according to the SGC. These include an increase in seismic energy associated with volcanic tremor (continuous ground vibration caused by the movement of fluids, gases, and magma), ash emissions reaching up to 3,400 meters above the crater, higher columns of gas and ash, and ground deformation in the area between the Purace, Piocollo, and Curiquinga volcanoes.

There has also been an increase in sulfur dioxide (SO₂) emissions, higher concentrations of carbon dioxide (CO₂), and ground deformation between the Purace, Piocollo, and Curiquinga volcanoes. According to the SGC, these are the highest instrumental values ever recorded for this volcano.

With the UNGRD measure, coordination with local and departmental authorities and emergency response agencies was strengthened to reinforce the institutional response to any eventual event.

The agency also urged residents in the areas of influence of Purace Volcano not to enter the crater zones while geological monitoring continues, and to remain informed only through official channels in order to prevent the spread of unverified information about the volcano’s behavior.

Purace’s main crater is located at an elevation of 4,630 meters above sea level. According to the volcanic hazard map for Purace Volcano, prepared by the SGC in 2014, the area of influence of this geological structure is inhabited mainly by Indigenous and farming communities.

The municipalities at risk in the event of a major eruption are Purace, Popayan, and Sotara, all located in the department of Cauca. Also at risk are the Indigenous Reserves of Purace, Kokonuko, and Paletara, the Juan Tama Indigenous resettlement of the Paez ethnic group (Nasa people), and the Misak settlement, Indigenous territories belonging to the Kokonuko ethnic group or people.

These communities could experience volcanic phenomena such as pyroclastic flows (in the case of Purace) and lahars or mudflows (affecting the community of Paletara and the city of Popayan).

Following the change in the alert level for Purace Volcano from yellow to orange, the Government of the department of Huila also strengthened its monitoring of the volcanic system’s activity.

A highly unstable volcano

Since 2021, Purace Volcano has been showing gradual changes in its activity, according to the SGC. One of the most notable was the increase in seismic activity recorded in March 2022, the month in which the highest number of daily earthquakes was recorded since the SGC began monitoring the volcano.

These variations occurred before a small phreatic eruption took place at the crater of Curiquinga Volcano on March 29, 2022. Curiquinga is one of the fifteen volcanoes that, together with Purace, make up the CVLC. At that time (March 30, 2022), the SGC changed the volcano’s alert status to yellow due to the high variability observed in the number and location of fracture earthquakes and fluid movement events following the eruption.

Two years later, on May 3, 2024, the SGC again changed the volcano’s alert status to orange because of significant variations in three variables: seismicity, ground deformation, and changes in the type of gases and fluids emitted by the volcanic system.

That alert level remained in effect until July 5, 2024. Since then, the volcano’s behavior has remained unstable, and on November 29, 2025, its alert status was once again raised to orange because of changes and increases in seismic activity, as well as the occurrence of ash emissions, which had not been recorded since 1977.

The volcano remained under orange alert until January 22, 2026, when it returned to yellow alert status.

The SGC’s Popayan Volcanological and Seismological Observatory has been monitoring the activity of Purace Volcano since 1993. It is currently one of the best-instrumented volcanoes in the country, meaning it has one of the largest numbers of monitoring instruments to understand its behavior and changes in its activity.

It currently has a monitoring network consisting of 97 stations, 60 of which are equipped with a data telemetry system, while data from the remaining 37 stations are collected directly at sampling points.