Warning! Mount Semeru Erupts Again This Morning (Tuesday, December 2, 2025)

Mount Semeru in East Java erupted again on Tuesday (12/2/2025) at 10:04 AM WIB. In the last week, Mount Semeru has erupted 26 times.

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

The eruption visuals were not observed. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Number of Natural Disaster Incidents in Provinces on Java Island 2020-2024)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on December 2, 2025, at 00:00-06:00 WIB, showed 46 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 66-194 seconds.

Furthermore, there were 5 rockfall earthquakes with amplitudes of 4-8 mm and durations of 44-126 seconds, and 1 deep volcanic earthquake with an amplitude of 15 millimeters, s-p 2.7 seconds, and a duration of 30 seconds.

PVMBG urges against any activity in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond that distance, people should not engage in activities within 500 meters from the riverbanks along Besuk Kobokan, as there is a potential for hot cloud expansion and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,150 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,905 occurrences.

(Read: Number of Natural Disaster Victims in Indonesia as of July 8, 2025)