Mount Semeru Erupts Again Tonight, Ash Column Reaches 800 Metres Above Summit

Jakarta, VIVA – Mount Semeru erupted again on Tuesday evening, with the eruption column reaching 800 metres above the summit. The volcano is situated on the border of Lumajang and Malang regencies in East Java.

“An eruption of Mount Semeru occurred at 21:50 Western Indonesian Time, with the eruption column observed at approximately 800 metres above the summit, or 4,476 metres above sea level,” said Sigit Rian Alfian, an officer at the Mount Semeru Observation Post, in a written report received in Lumajang on Tuesday evening, 17 February 2026.

The volcanic ash column was observed to be white to grey in colour, with thick intensity drifting eastward and southeastward. “The eruption was recorded on the seismograph with a maximum amplitude of 21 mm and a duration of 119 seconds,” he said.

According to records kept by monitoring officers, Mount Semeru erupted a total of eight times on Tuesday, with the first eruption occurring at 00:17 Western Indonesian Time. The visual aspect of that eruption was not observed as it was obscured by fog.

He explained that Mount Semeru is currently at volcanic activity Level III (Alert), prompting the Centre for Volcanology and Geological Hazard Mitigation (PVMBG) to issue a number of recommendations. Residents are prohibited from carrying out any activities in the southeast sector along Besuk Kobokan, within 13 kilometres of the summit (eruption centre).

Beyond that distance, he said, residents must not undertake activities within 500 metres of the riverbanks along Besuk Kobokan, owing to the potential for pyroclastic flow expansion and lahars extending up to 17 kilometres from the summit.

“Residents are also prohibited from any activity within a five-kilometre radius of the crater or summit of Mount Semeru, due to the danger of incandescent rock projectiles,” he said.

The public should remain vigilant against the potential for pyroclastic flows, lava avalanches and lahars along river courses and valleys originating at the summit of Mount Semeru, particularly along Besuk Kobokan, Besuk Bang, Besuk Kembar and Besuk Sat, as well as the potential for lahars in smaller tributaries of Besuk Kobokan.