Warning! Mount Semeru Erupts Again Tonight (Sunday, October 26, 2025)

Mount Semeru in East Java erupted again on Sunday (October 26, 2025) at 10:38 PM WIB. In the past week, Mount Semeru has erupted 43 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 observed was approximately 900 meters above the peak (4,576 meters above sea level).

The ash column was observed to be white to grey with thick intensity towards the west. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 129 seconds.

(Read: Majority of Indonesians Access Air Quality Information from Social Media)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on October 26, 2025, from 00:00-23:59 WIB showed 39 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 68-174 seconds.

Subsequently, there were 13 rockfall earthquakes with amplitudes of 2-5 mm and durations of 37-132 seconds, and 3 emission earthquakes with amplitudes of 5-7 millimeters and durations of 49-63 seconds.

PVMBG urges against any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, the public is advised not to conduct 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 6,787 volcano eruptions across Indonesia. Mount Semeru in East Java recorded the most eruptions with 2,683 occurrences.

(Read: Not Jakarta, These are the Areas with the Worst Air Quality in Indonesia (Wednesday, June 7, 2023))