Warning! This Morning Mount Semeru Erupts Again (Wednesday, January 21, 2026)

Mount Semeru in East Java erupted again on Wednesday (1/21/2026) at 08:37 AM Western Indonesia Time. In the last week, Mount Semeru has erupted 8 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the observed ash column height reached None meters above the peak (None meters above sea level).

The eruption visual was not observed. Mount Semeru's eruption is still ongoing when this report was made.

(Read: Air Quality in Indonesia Slightly Improved in 2021)

According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level III (Siaga/Alert). Seismicity observations on January 21, 2026, from 00:00-06:00 AM Western Indonesia Time, showed 27 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 73-145 seconds.

Subsequently, there were 2 avalanche earthquakes with amplitudes of 2-3 mm and durations of 50-68 seconds, and 2 exhalation earthquakes with amplitudes of 4-6 millimeters and durations of 48-55 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 engage in activities within 500 meters from the river bank (river border) along Besuk Kobokan because of the potential for expansion of hot clouds and lahars up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 282 volcano eruptions in all of Indonesia. Mount Semeru in East Java has erupted the most with 154 explosions.

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