Mount Semeru erupts, ash column reaches 600 meters

Lumajang, Jawa Timur (ANTARA) - Mount Semeru, located on the border of Lumajang and Malang districts in East Java, erupted on Wednesday, spewing an ash column 600 meters above its summit.

An eruption occurred at Mount Semeru on Wednesday June 24, 2026, at 06:22 a.m. Western Indonesian Time with the observed eruption column reaching around 600 meters above the summit, or 4,276 meters above sea level, Mount Semeru Observation Post Officer Yadi Yuliandi said in a written report received in Lumajang on Wednesday.

According to Yadi, the eruption produced a thick gray ash column that drifted westward. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and lasted 130 seconds.

Based on observations from midnight to 06:00 a.m. on Wednesday, Mount Semeru recorded 14 eruption earthquakes with amplitudes of 15-22 millimeters, three avalanche earthquakes with amplitudes of 2-4 millimeters, two emission earth quakes with amplitudes of 3-4 milimeters, one harmonic tremor with an amplitude of 1 millimeter, and one distant tectonic earthquake with an amplitude of 15 millimeters.

Yadi said the Mount Semeru's volcanic activity is currently at Level III status with a recommendation that people refrain from carrying out any activities in the south eastern sector along Besuk Kobokan within 13 kilometers of the summit, or the eruption center.

Beyond that distance, he said, people should not carry out activities within 500 meters of riverbanks along Besuk Kobokan, as the area could be affected by the expansion of pyroclastic clouds and lava flows up to 17 kilometers from the summit.

"People are prohibited from carrying out activities within five kilometer radius of Mount Semeru's crater or summit due to the risk of incandescent rock ejections," he said.

He urged residents to remain alert for potential pyroclastic clouds, lava avalanches along rivers and valleys originating from Mount Semeru's summit.

"This applies especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lava in small rivers that are tributaries of Besuk Kobokan," Yadi added.

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Translator: Bayu Prasetyo

Editor: M Razi Rahman

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