Purace volcano (Colombia): alert status raised to Orange

Purace volcano on 3 April (image: Servicio Geológico Colombiano)

Purace volcano on 3 April (image: Servicio Geológico Colombiano)

Since the declaration of the Orange alert status, a seismic activity related to fracture and fluid movements has exhibited a consistent pattern in terms of the number of events and released energy.
The majority of earthquakes stemming from rock fracturing were detected beneath the crater of the volcano and on its eastern flank, occurring at depths ranging from 0.8 to 4 km. The highest magnitude recorded was M 1.6, observed yesterday at 10:50 local time. The seismic activity associated with fluid movement was concentrated around the crater and its northern flank, occurring at depths shallower than 0.8 km. Furthermore, earthquakes linked to the rise, emplacement, or movement of magma have been documented, potentially forming domes or protuberances that may or may not breach the surface.

Observations reveal a maximum gas column height of approximately 1,400 m, measured from the volcano’s summit, with a dispersion direction towards the west. Soil deformation processes and concentrations of carbon dioxide (CO2) and sulfur dioxide (SO2) emissions remain elevated compared to baseline levels.
The SGC volcano observatory affirms that the alert level for the volcano remains at Orange, signifying significant changes in monitored parameters. Although fluctuations in seismic activity and degassing levels may occur, this does not indicate a return to normal volcanic activity levels. Transitioning back to a lower alert state (Yellow) requires a sustained period during which all monitored parameters are assessed, identifying trends indicative of increased stability. However, if there is an acceleration in processes suggesting an imminent eruption or an eruption itself, the alert status will be escalated to Red.

Source: Servicio Geológico Colombiano volcano activity update 5 May 2024