Mount Semeru, located in East Java, reportedly erupted again on Saturday, July 4, 2026, at 06:08 WIB. The eruption produced a volcanic ash column reaching a height of 1,400 meters above the peak, with observed white-to-gray ash material moving towards the south.
According to seismogram records, this eruption had a maximum amplitude of 22 millimeters and lasted for 2 minutes and 17 seconds. As of this report, volcanic activity on the highest mountain on Java Island is still ongoing.
The Center for Volcanology and Geological Hazard Mitigation (PVMBG) maintains Mount Semeru's status at Level III (Alert). The public is advised to increase vigilance, particularly regarding the potential for pyroclastic flows that could occur at any time due to the accumulation of volcanic material on the mountain slopes.
Regarding public safety, authorities have established a total exclusion zone for community activities. This prohibition covers the southeastern sector along Besuk Kobokan up to 13 kilometers from the eruption center. In addition, a 5-kilometer radius from the crater has also been declared a restricted zone due to the threat of incandescent rock projectiles.
Residents are strictly prohibited from conducting activities along rivers originating from the peak of Semeru, such as Besuk Bang, Besuk Kembar, and Besuk Sat, to minimize the risk of being trapped in lahar flows or lava avalanches that could extend up to 17 kilometers at any time.
