Mount Semeru Erupts Again Tonight (Friday, December 12, 2025)

Mount Semeru in East Java erupted again on Friday (12/12/2025) at 00.42 WIB. In the last week, Mount Semeru has erupted 31 times.

According to eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the observed ash column reached None meters above the peak (None meters above sea level).

No visual eruption was observed. The Mount Semeru eruption was still ongoing when this report was made.

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According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on December 12, 2025, from 18.00-23.59 WIB, showed 19 eruption tremors/earthquakes with amplitudes of 10-23 millimeters and durations of 67-190 seconds.

Then, there were 2 rockfall tremors with amplitudes of 2-5 mm and durations of 48-59 seconds, and 19 emission tremors with amplitudes of 3-8 millimeters and durations of 20-90 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, up to 13 kilometers from the peak (eruption center). Beyond that distance, people should not engage in activities within 500 meters of the riverbank (river boundary) along Besuk Kobokan due to the potential for expanding hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,308 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 3,009 occurrences.

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