Warning! Mount Semeru Erupts Again Tonight (Thursday, October 30, 2025)

Mount Semeru in East Java erupted again on Thursday (10/30/2025) at 00:57 AM Western Indonesian Time (WIB). In the last week, Mount Semeru has erupted 26 times.

Citing 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 600 meters above the peak (4,276 meters above sea level).

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

(Read: Indication of Forest and Land Fire Area in East Kalimantan until June 2025)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on October 30, 2025, from 00:00-23:59 WIB, showed 126 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 54-165 seconds.

Then, 25 rockfall earthquakes with amplitudes of 2-8 mm and earthquake durations of 44-86 seconds, and 23 exhalation earthquakes with amplitudes of 3-9 millimeters and earthquake durations of 30-91 seconds occurred.

PVMBG urges against any activity in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, the public is advised not to engage in activities within 500 meters from the riverbanks (river borders) along Besuk Kobokan due to the potential for expansion of hot clouds and lahar flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,827 volcano eruptions across Indonesia. Mount Semeru in East Java has had the most eruptions, with 2,709 occurrences.

(Read: 55 Disasters Occurred in Mid-September 2023, Forest and Land Fires Dominated)