Warning! Mount Semeru Erupts Again Tonight (Tuesday, December 2, 2025)

Mount Semeru in East Java erupted again on Tuesday (2/12/2025) at 10:01 PM WIB. In the last week, Mount Semeru has erupted 27 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the ash column was observed to be around 600 meters above the peak or 4,276 meters above sea level.

The ash column was observed to be white to gray with thick intensity towards the southwest and west. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 137 seconds.

(Read: Indications of Forest and Land Fire Area in West Kalimantan Province 2016-2025)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level III (Alert). Seismicity observations on December 2, 2025, from 12:00 PM to 6:00 PM WIB, showed 39 eruption tremors with amplitudes of 10-22 millimeters and durations of 65-170 seconds.

Additionally, there were 6 rockfall earthquakes with amplitudes of 3-5 mm and durations of 35-65 seconds, and 5 exhalation earthquakes with amplitudes of 3-6 millimeters and durations of 53-126 seconds.

PVMBG urges against any activity in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond that distance, people should not engage in activities within 500 meters of the riverbanks (river borders) along Besuk Kobokan due to the potential for being affected by the expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,153 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,906 recorded.

(Read: Many Forest and Land Fires in Concession Areas, Especially Oil Palm Concessions)