Mount Semeru Erupts Again This Afternoon (Saturday, September 20, 2025)

Mount Semeru in East Java erupted again on Saturday (September 20, 2025) at 4:52 PM WIB. 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 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 21 millimeters and a duration of 107 seconds.

(Read: Indonesia, Country with the Worst Air Quality in Southeast Asia)

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismicity observations on September 20, 2025, from 00:00-23:59 WIB showed 62 eruption earthquakes with amplitudes of 10-22 millimeters and durations of 47-226 seconds.

Subsequently, there were 4 rockfall earthquakes with amplitudes of 2-5 mm and durations of 44-79 seconds, and 14 emission earthquakes with amplitudes of 3-8 millimeters and durations of 29-74 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, within 8 kilometers from the peak (eruption center). Beyond this distance, the public is advised not to engage in activities within 500 meters from the riverbanks (river boundaries) along Besuk Kobokan, as there is a potential for hot clouds and lahar flows to extend up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,181 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,464 times.

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