Mount Semeru again showed an increase in volcanic activity on Friday, July 3, 2026. According to a report from the Semeru Volcano Observation Post (PGA), two eruptions were recorded within a span of a few hours in the morning. The latest eruption observed at 09:48 WIB produced a volcanic ash column 1,300 meters high above the peak, or reaching 4,976 meters above sea level.
Previously, the tallest mountain on Java Island also erupted at 08:45 WIB, with the ash column height reaching 800 meters. Seismograph data recorded a maximum amplitude of 22 millimeters with a consistent eruption duration, indicating that magma activity fluctuations within the crater remain high.
In addition to eruptive activity, a number of rockfall earthquakes, emission earthquakes, and distant tectonic earthquakes were also recorded during the same observation period. Although the visual condition of the mountain appeared clear, the Center for Volcanology and Geological Hazard Mitigation (PVMBG) still emphasized the importance of extra vigilance for people active around the slopes.
As a precautionary measure, PVMBG has established an exclusion zone of 13 kilometers in the southeastern sector along Besuk Kobokan. Residents are also prohibited from conducting activities within a 5-kilometer radius of the eruption center to avoid the risk of projected incandescent material. Furthermore, the public is asked to stay away from the banks of rivers originating from the peak of Semeru to avoid the potential hazard of lahar flows and pyroclastic flows.
Authorities urge the public to only refer to official information regarding the status of Mount Semeru. Vigilance must be maintained given the dynamic characteristics of Semeru's volcanic activity and the potential for subsequent eruptions at any time.
