Mount Semeru Erupts Again This Morning, Ash Plume 700 Meters Above Peak

Mount Semeru in East Java erupted again on Thursday (25/9/2025) at 06:56 AM WIB. In the last week, Mount Semeru has erupted 19 times.

Citing eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the ash plume was observed to be approximately 700 meters above the peak (4,376 meters above sea level).

The ash plume was observed to be gray with thick intensity to the north. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 129 seconds.

(Read: Nearly 5 Thousand Natural Disaster Incidents in Indonesia Throughout 2023, Forest and Land Fires Dominate)

According to MAGMA Indonesia''s volcano activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 25, 2025, from 00:00-23:59 WIB showed 74 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 56-176 seconds.

Followed by 5 rockfall earthquakes with amplitudes of 2-3 mm and durations of 34-102 seconds, and 10 gas emission earthquakes with amplitudes of 3-8 millimeters and durations of 19-98 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, the public should not engage in activities within 500 meters from the riverbanks along Besuk Kobokan, as there is a potential for expansion of hot clouds and lahar flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,317 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,485 occurrences.

(Read: BNPB Recorded 52 Natural Disasters in Mid-August 2023, Forest and Land Fires Most Numerous)