Mount Semeru Erupts Again Tonight (Monday, December 15, 2025)

Mount Semeru in East Java erupted again on Monday (December 15, 2025) at 19:20 WIB. In the last week, Mount Semeru has erupted 5 times.

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

The visual eruption was not observed. The eruption of Mount Semeru was still ongoing when this report was made.

(Read: 4.1 M Earthquake Shakes Phala, Hawaii)

According to the MAGMA Indonesia volcanic activity report, the activity level of Mount Semeru is at Level III (Alert). Seismic observations on December 15, 2025, at 12:00-18:00 WIB showed 43 eruption earthquakes with amplitudes of 10-23 millimeters and earthquake durations of 53-128 seconds.

Then, there was 1 rockfall earthquake with an amplitude of 5 mm and an earthquake duration of 54 seconds, and 2 emission earthquakes with amplitudes of 4-7 millimeters and earthquake durations of 42-60 seconds.

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

Throughout 2025, MAGMA Indonesia has recorded 7,355 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 3,029 recorded.

(Read: 4.4 M Earthquake Shakes Babar, Indonesia)