Mount Semeru Erupts Again This Afternoon, Volcanic Ash Reaches 700 Meters Above Peak

Mount Semeru in East Java erupted again on Friday (9/26/2025) at 4:59 PM WIB. In the last week, Mount Semeru has erupted 33 times.

According to eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the observed ash column reached 700 meters above the peak (4,376 meters above sea level).

The observed ash column was white to gray with thick intensity towards the southwest. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 119 seconds.

(Read: Global Economic Losses Due to Floods Declined in 2023)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on September 26, 2025, from 00:00-23:59 WIB, showed 85 eruption earthquakes with amplitudes of 10-22 millimeters and durations of 51-192 seconds.

Additionally, there were 12 exhalation earthquakes with amplitudes of 4-8 millimeters and durations of 43-80 seconds, and 5 harmonic earthquakes with amplitudes of 2-8 millimeters and durations of 43-80 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 (river borders) 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 6,357 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,499 times.

(Read: Jakarta Roads Still Flooded (July 9, 2025, 09:00 AM WIB))