Mount Semeru Erupts Again This Morning (Monday, December 8, 2025)

Mount Semeru in East Java erupted again on Monday (8/12/2025) at 10:30 AM WIB. In the last week, Mount Semeru has erupted 5 times.

Based on 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).

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

(Read: Countries with the Most Active Volcanoes in the World, Indonesia Ranks First)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on December 8, 2025, from 00:00-06:00 WIB, showed 41 eruption earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 62-180 seconds.

Then, 2 rockfall earthquakes with amplitudes of 8-10 mm and durations of 44-79 seconds, and 2 exhalation earthquakes with amplitudes of 6-8 millimeters and durations of 62-65 seconds occurred.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond this distance, the public should not engage in activities within 500 meters from the riverbanks (river boundaries) along Besuk Kobokan, as there is potential for expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,258 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,983 eruptions.

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