A loud rumble and intense smell of sulfur recorded this Sunday at Turrialba volcano raised alarms among residents and park rangers, although initial analyses rule out, for now, an explosive eruption linked to the event.

What happened at Turrialba volcano

Around midday, staff at Turrialba Volcano National Park reported hearing a loud rumble accompanied by a sulfur smell coming from the massif. The signal was detected at 12:03 p.m. by seismographs and infrasound acoustic sensors installed in the area, allowing specialists to analyze the origin of the phenomenon. The Volcanological and Seismological Observatory of Costa Rica (OVSICORI-UNA) reviewed the records and concluded that the rumble is primarily associated with an internal collapse inside the crater.

Expert analysis

According to OVSICORI, the instruments recorded a signal characteristic of a material collapse within the crater, with no evidence of an eruption with significant ash emission. During a field inspection carried out the following morning, volcanologists found no fresh ash deposits or other typical signs of a recent eruption. The cameras monitoring the volcano were unable to capture the moment of the collapse due to heavy cloud cover at the summit.

Recent activity at Turrialba

Turrialba volcano maintains activity considered low to moderate, with gas emissions and sporadic small explosions that are part of its current behavior. So far in March, episodes of ash columns several hundred meters high have been reported, as well as seismic signals associated with internal fluid movements. Authorities note that, although there is no ongoing eruption linked to the rumble, Turrialba remains an active volcano requiring constant monitoring.

Recommendations to the population

OVSICORI and the National Seismological Network recommend respecting access restrictions to the crater and following only authorized trails within the National Park. Residents and visitors are asked to immediately report any ash fall, persistent strong sulfur smell, or noticeable changes in volcanic activity to the relevant authorities. Institutions urge the public to rely on official channels and avoid spreading rumors about supposed “major eruptions” not backed by scientific observatories.

Official sources

• OVSICORI-UNA: activity reports on Turrialba volcano and communiqué on the rumble and internal crater collapse.
• National Seismological Network (RSN-UCR-ICE): reports on seismic and volcanic activity at Turrialba.
• Turrialba Volcano National Park and National System of Conservation Areas (SINAC): notices on access, safety, and visit regulations.