Warning! Mount Semeru Erupts Again This Afternoon (Monday, September 15, 2025)

Mount Semeru in East Java erupted again on Monday (9/15/2025) at 17:40 WIB. In the last week, Mount Semeru has erupted 4 times.

Reporting 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 or None meters above sea level.

The eruption visual was not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 100 seconds.

(Read: Jakarta''s Air Quality This Morning is the Second Worst in the World (Friday, June 17, 2022))

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 15, 2025, from 00:00-23:59 WIB showed 53 eruption tremors with amplitudes of 10-22 millimeters and durations of 54-221 seconds.

Then, 2 rockfall tremors with amplitudes of 4-6 mm and durations of 55-66 seconds, and 2 exhalation tremors with an amplitude of 6 millimeters and durations of 32-65 seconds occurred.

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 conduct activities within 500 meters from the riverbanks (river boundaries) along Besuk Kobokan as there is a potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,111 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,451 eruptions.

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