Mount Semeru Erupts Again Tonight (Wednesday, October 8, 2025)

Mount Semeru in East Java erupted again on Wednesday (8/10/2025) at 00.37 WIB. In the last week, Mount Semeru has erupted 22 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 300 meters above the peak or 3,976 meters above sea level.

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

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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 October 8, 2025, from 00.00-23.59 WIB showed 103 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and a duration of 41-188 seconds.

Furthermore, there were 4 exhalation earthquakes with amplitudes of 4-6 millimeters and a duration of 32-48 seconds, and 2 distant tectonic earthquakes with amplitudes of 8-15 millimeters s-p 15-19 seconds and a duration of 48-53 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 along Besuk Kobokan due to the potential for being affected by expanding hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,576 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 2,583 occurrences.

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