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

Mount Semeru in East Java erupted again on Wednesday (Jan 21, 2026) at 17:33 WIB. In the last week, Mount Semeru has erupted 10 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 approximately None meters above the peak or None meters above sea level.

The visual eruption was not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 113 seconds.

(Read: Trends in Volcanic Eruptions in Recent Years)

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level III (Alert). Seismic observations on January 21, 2026, from 06:00-12:00 WIB, showed 34 eruption/volcanic earthquakes with amplitudes of 15-22 millimeters and earthquake durations of 65-149 seconds.

Furthermore, 4 emission earthquakes with amplitudes of 5-6 millimeters and earthquake durations of 47-53 seconds, and 1 harmonic tremor with an amplitude of 2 millimeters and an earthquake duration of 149 seconds occurred.

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

Throughout 2026, MAGMA Indonesia has recorded 288 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 156 occurrences.

(Read: Countries with the Most Active Volcanoes in the World, Indonesia Ranks First)