Mount Semeru Erupts Again This Afternoon (Tuesday, April 21, 2026)

Mount Semeru in East Java erupted again on Tuesday (April 21, 2026) at 14:10 WIB. In the past week, Mount Semeru has erupted 10 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 or None meters above sea level.

No visual observation of the eruption was made. The eruption of Mount Semeru was still ongoing when this report was compiled.

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According to the MAGMA Indonesia volcanic activity report, the activity level of Mount Semeru is at Level III (Alert). Seismic observations on April 21, 2026 from 06:00 to 12:00 WIB showed 16 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 82-182 seconds.

Then, 3 emission earthquakes with amplitudes of 6-7 millimeters and durations of 57-68 seconds, as well as 1 local tectonic earthquake with an amplitude of 40 millimeters, s-p time of 7.5 seconds, and duration of 32 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, within 13 kilometers of the peak (eruption center). Beyond that distance, residents are advised not to carry out activities within 500 meters of the riverbank along Besuk Kobokan due to the potential for being affected by the expansion of hot clouds and lahar flows up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 1,587 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 842 events.

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