Mount Semeru Erupts Again This Afternoon (Wednesday, September 17, 2025)

Mount Semeru in East Java erupted again on Wednesday (9/17/2025) at 4:31 PM WIB. In the last week, Mount Semeru has erupted 9 times.

According to 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 128 seconds.

(Read: Indonesia Has the Most Active Volcanoes in the World)

According to MAGMA Indonesia''s volcano activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 17, 2025, from 00:00-23:59 WIB showed 54 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 50-225 seconds.

Subsequently, there were 9 rockfall earthquakes with amplitudes of 2-8 mm and durations of 48-114 seconds, and 8 emission earthquakes with amplitudes of 4-8 millimeters and durations of 35-71 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, people should not engage in activities within 500 meters from the riverbanks along Besuk Kobokan as there is a potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,131 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,456 events.

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