Level III Alert! Mount Semeru Erupts Accompanied by Rumbling Sounds
The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) has released the latest update on the condition of Mount Semeru, East Java. An eruption was recorded on 10 September 2026 at 07:56 WIB.
However, the height of the ash column was not observed. This eruption was recorded on the seismogram with a maximum amplitude of 22 mm and a duration of approximately 1 minute and 50 seconds. “The eruption was accompanied by moderate rumbling sounds,” the Geological Agency explained on Thursday (10/9/2026).
Currently, Mount Semeru is at Level III (Alert) status with the following recommendations:
Do not engage in any activities in the south-eastern sector along Besuk Kobokan, up to 13 km from the summit (the centre of the eruption). Outside of that distance, the public should avoid activities within 500 metres of the riverbanks along Besuk Kobokan due to the potential for expanding pyroclastic clouds and lava flows up to 17 km from the summit.
Do not engage in any activities within a 5 km radius of the crater/summit of Mount Semeru due to the danger of volcanic rock fragments (incandescent rocks).
Remain vigilant regarding the potential for pyroclastic clouds, lava flows, and lahars along the riverbeds/valleys originating from the summit of Mount Semeru, particularly along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahars in small rivers that are tributaries to Besuk Kobokan.