Warning! Mount Semeru Erupts Again This Morning (Sunday, September 21, 2025)

Mount Semeru in East Java erupted again on Sunday (21/9/2025) at 08:01 AM WIB. In the last week, Mount Semeru has erupted 18 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the observed ash column was approximately None meters above the peak (None meters above sea level).

The eruption was not visually observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 140 seconds.

(Read: Countries with the Most Active Volcanoes in the World, Indonesia Ranks First)

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismicity observations on September 21, 2025, from 00:00-23:59 WIB, showed 52 eruption quakes/eruptions with amplitudes of 10-22 millimeters and durations of 60-194 seconds.

Additionally, there were 2 rockfall quakes with an amplitude of 2 mm and durations of 56-83 seconds, and 14 exhalation quakes with amplitudes of 4-8 millimeters and durations of 40-105 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, 8 kilometers from the peak (eruption center). Beyond this distance, the public should not engage in activities within 500 meters of the riverbank (river boundary) along Besuk Kobokan, as there is a potential for pyroclastic flows and lahars to extend up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,192 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,465 occurrences.

(Read: Indonesia Has the Most Active Volcanoes in the World)