Mount Semeru Erupts Again Tonight (Wednesday, October 29, 2025)

Mount Semeru in East Java erupted again on Wednesday (10/29/2025) at 00.25 WIB. In the last week, Mount Semeru has erupted 17 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the ash column height was observed to be around 500 meters above the peak (4,176 meters above sea level).

The ash column was observed to be white to gray with moderate intensity towards the southwest. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Floods, Natural Disasters That Frequently Hit Indonesia as of September 2025)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on October 29, 2025, from 00.00-23.59 WIB showed 115 eruption earthquakes with amplitudes of 10-22 millimeters and durations of 54-178 seconds.

Additionally, there were 6 rockfall earthquakes with amplitudes of 2-10 mm and durations of 43-77 seconds, and 10 gas emission earthquakes with amplitudes of 3-9 millimeters and durations of 19-60 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 boundaries) along Besuk Kobokan due to the potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,811 volcanic eruptions across Indonesia. Mount Semeru in East Java has had the most eruptions, with 2,700 events.

(Read: Floods Dominate Natural Disasters in Indonesia as of End of February 2024)