Mount Semeru Erupts Again Tonight, Ash Column 700 Meters Above Peak

Mount Semeru in East Java erupted again on Friday (9/26/2025) at 11:28 PM WIB. In the last week, Mount Semeru has erupted 37 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column reached 700 meters above the peak or 4,376 meters above sea level.

The ash column was observed to be white to grey with moderate intensity towards the west. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Indonesia Has the Most Active Volcanoes in the World)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on September 26, 2025, from 00:00-23:59 WIB showed 85 eruption tremors with amplitudes of 10-22 millimeters and durations of 51-192 seconds.

Additionally, there were 12 exhalation tremors with amplitudes of 4-8 millimeters and durations of 43-80 seconds, and 5 harmonic tremors with amplitudes of 2-8 millimeters and durations of 43-80 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, people should not engage in activities within 500 meters of the riverbanks (river borders) along Besuk Kobokan, as there is a potential for hot clouds and lava flows to extend up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,369 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,503 eruptions.

(Read: Volcanic Eruption Trends in Recent Years)