Mount Semeru Erupts Again This Morning, Ash Column Height Around 300 Meters

Mount Semeru in East Java erupted again on Saturday (10/4/2025) at 06:25 AM WIB. In the last week, Mount Semeru has erupted 29 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 reached 300 meters above the peak (3,976 meters above sea level).

The ash column was observed to be white to grey with thick intensity towards the southwest. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 110 seconds.

(Read: Trends in Volcanic Eruptions in Recent Years)

According to MAGMA Indonesia's volcano activity report, the activity level of Mount Semeru is at Level II (Alert). Seismic observations on October 4, 2025, from 00:00-23:59 WIB showed 80 eruption/explosion earthquakes with amplitudes of 11-23 millimeters and durations of 65-161 seconds.

Subsequently, 1 rockfall earthquake with an amplitude of 2 mm and a duration of 94 seconds, and 6 emission earthquakes with amplitudes of 4-7 millimeters and durations of 41-59 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 borders) along Besuk Kobokan due to the potential for being affected by the expansion of hot clouds and lahar flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,524 volcanic eruptions across Indonesia. Mount Semeru in East Java erupted the most, with 2,551 eruptions.

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