Colombian authorities are taking preparatory, mitigation, and communication actions as the alert level of the Nevado del Ruiz Volcano changed from Yellow (I) to Orange (II) on 30 March 2023, indicating a probable eruption in days or weeks. The change in activity level follows a significant increase in seismic activity associated with rock fracturing within the volcano since 24 March 2023.

According to the Colombian Geological Service (SGC), an eruption of the Nevado del Ruiz volcano could be more significant than those in the past decade. The worst-case scenario could result in the alert level changing from orange to red (III), representing the highest level of alert. Such an emergency would put more than 57,000 people in surrounding areas at risk.

The volcano has been erupting for approximately ten years, but all eruptions have been minor and limited to areas around the volcano, depending on the wind direction. However, if the activity level changes to red and the volcano erupts, the consequences could be significant. The expulsion of pyroclastic material, along with gases and fluids at high speeds and temperature, could affect municipalities in the area of influence, causing falling ash or denser material. The greatest threat would be lahars or mudflows, which could flow into the Magdalena and Chinchiná rivers, affecting surrounding populations along their course. Ashes could also affect crops, flora and fauna, air traffic, and air quality, posing significant health risks for people, such as respiratory, ocular, and skin risks.

In the event of an eruption, an energy wave of great magnitude would be released, and the SGC would evaluate this as the eruption signal, initiating the response protocol. Emergency services, including firefighters, Civil Defense, and Red Cross in the departments of Caldas and Tolima, and coordinators of the departmental Risk Management Units of Risaralda, Caldas, and Tolima, must be notified of the eruption within two minutes of the confirmation of the energy release.

The change in activity level of the Nevado del Ruiz volcano is a concerning development, and the Colombian Geological Service continues to monitor the situation closely. Authorities have urged local populations to stay informed and follow the recommendations of emergency services in the event of an eruption.