Warning! Mount Semeru Erupts Again This Morning (Sunday, December 21, 2025)

Mount Semeru in East Java erupted again on Sunday (12/21/2025) at 10:21 AM WIB. In the last week, Mount Semeru has erupted 68 times.

Reporting 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 around None meters above the peak (None meters above sea level).

Visual eruption was not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 99 seconds.

(Read: Almost 5 Thousand Natural Disaster Incidents in Indonesia Throughout 2023, Forest Fires Dominate)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismicity observations on December 21, 2025, from 00:00-06:00 WIB, showed 50 eruption earthquakes with amplitudes of 13-22 millimeters and durations of 95-132 seconds.

Furthermore, there were 12 avalanche earthquakes with amplitudes of 4-8 mm and durations of 20-71 seconds, and 2 exhalation earthquakes with amplitudes of 5-7 millimeters and durations of 40-47 seconds.

PVMBG urges people not to carry out 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 engage in activities within 500 meters from the riverbanks (river boundaries) along Besuk Kobokan due to the potential for expansion of hot clouds and lava flows up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,454 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 3,092 events.

(Read: There were 1,300 natural disasters in Indonesia until September 2024, here are the details)