Mount Semeru, located in Lumajang Regency, East Java, showed significant volcanic activity again on Friday morning (10/7/2026). The Center for Volcanology and Geological Hazard Mitigation (PVMBG) recorded the eruption taking place at 07:39 WIB, with the ash column height reaching 1,300 meters above the peak, or about 4,976 meters above sea level.
Volcanic material in the form of ash was observed to be white to gray with moderate intensity. The ash dispersion was reported moving north and northeast. As of this report, the status of Mount Semeru remains at Level III (Alert), considering that throughout 2026 the volcano has erupted 1,448 times.
Mount Semeru Monitoring Post officer Liswanto emphasized a strict ban on residents and tourists carrying out activities within a 5-kilometer radius of the crater center. This measure was taken to anticipate the danger of incandescent rock ejecta that could occur at any time.
Furthermore, the public is asked to stay away from the southeastern sector along Besuk Kobokan up to a distance of 13 km from the peak. A similar restriction applies to residents within 500 meters of riverbanks due to the risk of expanding pyroclastic flows and cold lava flows that could reach up to 17 km away.
PVMBG seismic records for the period from 00:00 to 06:00 WIB showed fairly high activity, including 18 eruption earthquakes, 4 rockfall earthquakes, as well as several emission and distant tectonic earthquakes. Authorities urge the public to remain alert to potential lava avalanches along river courses such as Besuk Bang, Besuk Kembar, and Besuk Sat.
