Mount Semeru, located in East Java, was observed erupting again on Saturday (4/7/2026) morning. The eruption occurred precisely at 06:08 WIB, spewing a column of volcanic ash approximately 1,400 meters above the crater peak.
According to the report from the Center for Volcanology and Geological Hazard Mitigation (PVMBG), the observed ash column was white to gray in color with moderate intensity. The volcanic material was seen drifting towards the south. This eruptive activity was recorded on a seismogram with a maximum amplitude of 22 millimeters and an initial duration of about 2 minutes and 17 seconds.
As of now, Mount Semeru's status remains at Level III (Alert). Authorities emphasize that the public should not conduct any activities in the southeastern sector along Besuk Kobokan, within a 13-kilometer radius from the eruption center. A similar restriction applies outside this radius, specifically 500 meters from the riverbanks along Besuk Kobokan, due to the threat of expanding pyroclastic flows and lahar flows up to 17 kilometers.
In addition to the threat of pyroclastic flows, the public is also advised to stay away from a 5-kilometer radius from the crater peak to avoid the danger of incandescent rock ejecta. Residents living near river basins originating from the peak of Mount Semeru, such as Besuk Bang, Besuk Kembar, and Besuk Sat, are urged to exercise extra vigilance regarding potential lava flows and lahars that could occur at any time.
