Mount Semeru Erupts Again This Morning (Monday, April 20, 2026)

Mount Semeru in East Java erupted again on Monday (April 20, 2026) at 09:01 WIB. In the past week, Mount Semeru has erupted only once.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height is approximately 500 meters above the peak or 4,176 meters above sea level.

The ash column was observed to be white to gray in color with thick intensity towards the southwest. The eruption was recorded on the seismograph with a maximum amplitude of 22 millimeters and a duration of 130 seconds.

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According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level III (Alert). Earthquake observations on April 20, 2026, from 00:00 to 06:00 WIB showed 20 eruption/explosion earthquakes with amplitudes of 15-22 millimeters and durations of 87-225 seconds. Then, 3 emission earthquakes with amplitudes of 3-5 millimeters and durations of 42-67 seconds.

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

Throughout 2026, MAGMA Indonesia has recorded 1,568 volcanic eruptions across Indonesia. Mount Semeru in East Java has the most eruptions with 833 explosions.

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