Mount Semeru again showed an increase in volcanic activity on early Monday morning, July 13, 2026. The peak of the highest mountain on Java Island was recorded spewing a volcanic ash column 1.2 kilometers high toward the southwest. This phenomenon, observed since 00:49 WIB, indicates a significant eruption intensity, with more than 18 subsequent eruptions recorded until noon.
According to reports from the Semeru Volcano Observatory, seismic data shows intense unrest within the earth. During the first six hours of Monday, 33 eruption earthquakes, 12 rockfall earthquakes, and several other seismic activities such as harmonic, gust, and distant tectonic earthquakes were recorded. This figure continues the increasing trend of activity seen since the previous day, when a total of 89 earthquakes were detected in a single day.
Responding to this situation, the Acting Head of the Lumajang Regency Regional Disaster Management Agency (BPBD), Isnugroho, emphasized that Mount Semeru's current status remains at Level III (Alert). The public is urged to increase vigilance against potential secondary hazards, such as pyroclastic flows, lava, and cold lahar flows that could threaten river courses originating from Semeru's peak.
Authorities strictly prohibit resident activities in the southeastern sector, particularly along the Besuk Kobokan river flow up to a radius of 13 kilometers from the peak. In addition, the public is forbidden from conducting activities within a 5-kilometer radius of the main crater to avoid the risk of incandescent rock ejection. Residents are also requested to maintain a safe distance of 500 meters from riverbanks as a precautionary measure against pyroclastic flow hazards.
