Alert! Mount Semeru Erupts Again Tonight (Thursday, April 9, 2026)

Mount Semeru in East Java erupted again on Thursday (April 9, 2026) at 8:29 PM WIB. In the past week, Mount Semeru has erupted 36 times.

Quoting eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height reached 800 meters above the peak or 4,476 meters above sea level.

The ash column was observed to be white to gray in color with thick intensity towards the east. The eruption was recorded on the seismograph with a maximum amplitude of 22 millimeters and a duration of 138 seconds.

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

According to the MAGMA Indonesia volcano activity report, the activity level of Mount Semeru is at Level III (Alert). Earthquake observations on April 9, 2026 from 12:00 PM to 6:00 PM WIB showed 10 eruption/explosion earthquakes with amplitudes of 12-22 millimeters and durations of 50-130 seconds.

Then, 1 hot cloud avalanche earthquake with an amplitude of 18 mm and duration of 170 seconds, as well as 2 avalanche earthquakes with amplitudes of 3-7 mm and durations of 60-62 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, up to 13 kilometers from the peak (eruption center). Beyond that distance, residents should avoid activities within 500 meters of the riverbank along Besuk Kobokan due to the potential for hot cloud expansion and lahar flow up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 1,384 volcanic eruptions across Indonesia. Mount Semeru in East Java has the most eruptions with 744 events.

(Read: Trend of Volcanic Eruptions in Recent Years)