Warning! Mount Semeru Erupts Again This Afternoon (Sunday, October 26, 2025)

Mount Semeru in East Java erupted again on Sunday (10/26/2025) at 4:20 PM WIB. In the last week, Mount Semeru has erupted 40 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 approximately None meters above the peak (None meters above sea level).

Eruption visuals were not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 113 seconds.

(Read: Not Jakarta, These Are the Areas with the Worst Air Quality in Indonesia (Wednesday, June 7, 2023))

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on October 26, 2025, from 00:00-23:59 WIB showed 39 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 68-174 seconds.

Subsequently, there were 13 rockfall earthquakes with amplitudes of 2-5 mm and durations of 37-132 seconds, and 3 exhalation earthquakes with amplitudes of 5-7 millimeters and durations of 49-63 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 river banks (riverine borders) along Besuk Kobokan as there is a potential for hot cloud expansion and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,781 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,680 times.

(Read: Jatibening Enters the List of 15 Areas with the Best Air Quality in Indonesia as of September 2023)