Mount Semeru Erupts Again This Afternoon (Friday, October 17, 2025)

Mount Semeru in East Java erupted again on Friday (17/10/2025) at 11:07 AM WIB. In the last week, Mount Semeru has erupted 19 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 None meters above the peak (None meters above sea level).

No visual eruption was observed. Mount Semeru's eruption was still ongoing when this report was made.

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

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on October 17, 2025, from 00:00-23:59 WIB, showed 53 eruption tremors/earthquakes with amplitudes of 10-22 millimeters and durations of 51-143 seconds.

Furthermore, there were 3 rockfall tremors with amplitudes of 3-8 mm and durations of 45-81 seconds, and 2 exhalation tremors with amplitudes of 2-8 millimeters and durations of 63-66 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, the public 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 6,686 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,632 events.

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