Mount Semeru Erupts Again This Morning (Thursday, September 4, 2025)

Mount Semeru in East Java erupted again on Thursday (4/9/2025) at 05:01 AM WIB. In the last week, Mount Semeru has erupted 16 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 or None meters above sea level.

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

(Read: 4.4 M Earthquake Shakes Babar, Indonesia)

According to MAGMA Indonesia''s volcano activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 4, 2025, from 00:00-23:59 WIB showed 45 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 50-179 seconds.

Subsequently, there were 2 rockfall earthquakes with amplitudes of 6-10 mm and durations of 63-80 seconds, and 2 exhalation earthquakes with an amplitude of 8 millimeters and durations of 53-55 seconds.

PVMBG advises against any activities in the southeastern 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 river bank (river border) 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 5,956 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,384 occurrences.

(Read: 4.2 M Earthquake Shakes Fox Aleutian Islands)