Mount Semeru Erupts Again This Dawn (Thursday, September 25, 2025)

Mount Semeru in East Java erupted again on Thursday (25/9/2025) at 01:25 AM Western Indonesia Time. In the last week, Mount Semeru has erupted 17 times.

Citing 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 600 meters above the peak or 4,276 meters above sea level.

The ash column was observed to be white to gray with thick intensity towards the east. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 127 seconds.

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According to MAGMA Indonesia''s volcanic 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.

Furthermore, 5 rockfall earthquakes with amplitudes of 2-3 mm and durations of 34-102 seconds, and 10 exhalation earthquakes with amplitudes of 3-8 millimeters and durations of 19-98 seconds occurred.

PVMBG urges people not to carry out any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, the public is advised not to engage in activities within 500 meters from the riverbanks (river borders) along Besuk Kobokan, as there is a potential for pyroclastic flows and lahar flows to extend up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,312 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,483 occurrences.

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