Mount Semeru Erupts Again Tonight (Friday, October 17, 2025)

Mount Semeru in East Java erupted again on Friday (17/10/2025) at 20.25 Western Indonesian Time (WIB). In the last week, Mount Semeru has erupted 21 times.

Citing 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 or None meters above sea level.

The visual eruption was not observed. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 119 seconds.

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

According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on October 17, 2025, at 00.00-23.59 WIB showed 53 eruption/explosion earthquakes with an amplitude of 10-22 millimeters and a duration of 51-143 seconds.

Then, 3 times of rockfall earthquakes with an amplitude of 3-8 mm and a duration of 45-81 seconds, and 2 times of gas emission earthquakes with an amplitude of 2-8 millimeters and a duration of 63-66 seconds.

PVMBG advises against any activity in the southeastern sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond this distance, the public is advised not to conduct activities within 500 meters from the riverbank (river boundary) along Besuk Kobokan as there is a potential for hot cloud expansion and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,691 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,634 eruptions.

(Read: Air Quality in Bangladesh is the Worst in the World, How About Indonesia?)