Alert! Mount Semeru Erupts Again This Afternoon (Saturday, April 18, 2026)

Mount Semeru in East Java erupted again on Saturday (April 18, 2026) at 1:23 PM WIB. In the past week, Mount Semeru has erupted 51 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height reached None meters above the peak (None meters above sea level).

No eruption visuals were observed. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: Floods and Extreme Weather, the Most Disasters in Indonesia in 2025)

According to the MAGMA Indonesia volcanic activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on April 18, 2026 from 6:00 AM to 12:00 PM WIB showed 20 eruption/explosion earthquakes with amplitudes of 15-22 millimeters and durations of 70-132 seconds.

Additionally, there were 8 emission earthquakes with amplitudes of 2-6 millimeters and durations of 31-72 seconds, as well as 1 harmonic earthquake with an amplitude of 2 millimeters and a duration of 71 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, up to 13 kilometers from the peak (eruption center). Beyond this 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 expanding hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 1,546 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 826 events.

(Read: Distribution of Fatalities from Floods and Landslides in Aceh (December 9, 2025))