Warning! Mount Semeru Erupts Again This Afternoon (Monday, October 20, 2025)

Mount Semeru in East Java erupted again on Monday (10/20/2025) at 12:58 PM WIB. In the last week, Mount Semeru only erupted once.

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).

No visual eruption was observed. Mount Semeru's eruption is still ongoing as this report is being made.

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

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on October 20, 2025, at 00.00-23.59 WIB showed 81 eruption/explosion earthquakes with amplitudes of 10-23 millimeters and earthquake durations of 57-203 seconds.

Subsequently, 71 rockfall earthquakes with amplitudes of 2-9 mm and earthquake durations of 31-123 seconds, and 18 gas emission earthquakes with amplitudes of 3-9 millimeters and earthquake durations of 40-75 seconds occurred.

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 conduct activities within 500 meters from the riverbanks (river borders) along Besuk Kobokan, as there is a potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,717 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,641 occurrences.

(Read: Indication of Forest and Land Fire Area in Central Kalimantan Province in the Last Decade)