Mount Semeru, located on the border of Lumajang and Malang Regencies, East Java, showed volcanic activity once again with an eruption on Tuesday (30/6/2026). The event was recorded at 13:04 WIB, with the ash column reaching 900 meters above the peak.
An officer at the Mount Semeru Observation Post, Sigit Rian Alfian, confirmed that the observed ash column was thick with a white to gray color. The ash material was observed moving toward the northeast and east. Based on seismograph data, the eruption had a maximum amplitude of 21 millimeters and a duration of 99 seconds.
Overall, Mount Semeru has erupted five times between the early hours of the morning and Tuesday afternoon. The height of the eruption columns varied between 500 and 900 meters above the peak of Java's highest mountain.
Currently, the status of Mount Semeru remains at Level III (Alert). Authorities emphasized the ban on public activities within a five-kilometer radius from the crater or peak to avoid the risk of incandescent material ejection. Additionally, residents are advised not to carry out activities in the southeastern sector along Besuk Kobokan up to a radius of 13 kilometers from the eruption center.
The public is asked to remain vigilant against the threat of pyroclastic flows, lava avalanches, and lahar flows that could potentially occur along the river basins originating from Mount Semeru, such as Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat.
