Mount Semeru Erupts Again This Afternoon (Tuesday, September 30, 2025)

Mount Semeru in East Java erupted again on Tuesday (9/30/2025) at 11:01 AM WIB. In the last week, Mount Semeru has erupted 14 times.

According to 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 or None meters above sea level.

No visual eruption was observed. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Air Quality in Indonesia Improved Slightly in 2021)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on September 30, 2025, from 00:00-23:59 WIB showed 80 eruption earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 60-207 seconds.

Furthermore, there was 1 rockfall earthquake with an amplitude of 4 mm and a duration of 89 seconds, and 4 emission earthquakes with amplitudes of 3-8 millimeters and durations of 37-95 seconds.

PVMBG advises against any activity in the southeast 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 (river borders) along Besuk Kobokan due to the potential for being affected by the expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,466 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,536 eruptions.

(Read: West Kalimantan Has the Worst Air Quality in Indonesia This Morning (Friday, August 18, 2023))