Mount Semeru Erupts Again This Afternoon (Monday, October 6, 2025)

Mount Semeru in East Java erupted again on Monday (6/10/2025) at 4:00 PM Western Indonesian Time. In the last week, Mount Semeru has erupted 6 times.

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

The eruption visual was not observed. Mount Semeru's eruption was still ongoing when this report was made.

(Read: Volcanic Eruption Trends in Recent Years)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on October 6, 2025, from 00:00-23:59 Western Indonesian Time, showed 94 eruption/explosion earthquakes with amplitudes of 10-23 millimeters and durations of 40-202 seconds.

Additionally, there was 1 rockfall earthquake with an amplitude of 5 mm and a duration of 66 seconds, and 4 emission earthquakes with amplitudes of 4-6 millimeters and durations of 37-95 seconds.

PVMBG urges against any activities in the southeastern 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 along Besuk Kobokan due to the potential for being affected by expanding hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,554 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,567 events.

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