Warning! Mount Semeru Erupts Again Tonight (Saturday, August 9, 2025)

Mount Semeru in East Java erupted again on Saturday (August 9, 2025) at 23:51 WIB. In the last week, Mount Semeru has erupted 27 times.

Citing 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 reach 600 meters above the peak (4,276 meters above sea level).

The ash column was observed to be white to gray with thick intensity towards the southwest. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 99 seconds.

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According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on August 9, 2025, from 00:00-23:59 WIB, showed 53 eruption/explosion earthquakes with amplitudes of 12-22 millimeters and durations of 56-204 seconds.

Furthermore, there were 2 rockfall earthquakes with amplitudes of 5-8 mm and durations of 40-47 seconds, and 12 exhalation earthquakes with amplitudes of 4-8 millimeters and durations of 42-76 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond this distance, people should not engage in activities within 500 meters from the riverbanks (river borders) along Besuk Kobokan, as there is potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 5,537 volcanic eruptions/explosions across Indonesia. Mount Semeru in East Java has erupted the most with 2,212 occurrences.

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