Mount Semeru Erupts Again Tonight (Thursday, December 11, 2025)

Mount Semeru in East Java erupted again on Thursday (11/12/2025) at 00:53 WIB. In the last week, Mount Semeru has erupted 22 times.

According to eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the ash column observed reached 500 meters above the peak (4,176 meters above sea level).

The ash column was observed to be white to grey with thick intensity towards the southwest. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 128 seconds.

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According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismicity observations on December 11, 2025, from 18:00-23:59 WIB showed 37 eruption/explosion earthquakes with amplitudes of 10-23 millimeters and earthquake durations of 56-164 seconds.

Furthermore, there were 3 avalanche earthquakes with amplitudes of 2-3 mm and durations of 33-70 seconds, and 12 emission earthquakes with amplitudes of 3-8 millimeters and durations of 52-70 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond this distance, the public should not conduct activities within 500 meters of the riverbanks (river borders) along Besuk Kobokan due to the potential for hot cloud expansion and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,292 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 3,000 eruptions.

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