Mount Semeru Erupts Again Tonight, Ash Column 800 Meters Above Peak

Mount Semeru in East Java erupted again on Friday (19/12/2025) at 22:26 WIB. In the last week, Mount Semeru has erupted 40 times.

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

The ash column was observed to be white to grey with thick intensity towards the east. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 140 seconds.

(Read: There Have Been 1,300 Natural Disasters in Indonesia Until September 2024, Here Are the Details)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on December 19, 2025, from 12:00-18:00 WIB showed 4 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 55-99 seconds.

Furthermore, there were 3 emission earthquakes with amplitudes of 4-7 millimeters and durations of 37-53 seconds, and 1 distant tectonic earthquake with an amplitude of 11 millimeters, S-P 17 seconds, and a duration of 52 seconds.

PVMBG advises 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 conduct activities within 500 meters from 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 7,414 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 3,064 events.

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