Mount Semeru Erupts Again This Afternoon, Volcanic Ash Plume Approximately 300 Meters High

Mount Semeru in East Java erupted again on Saturday (13/9/2025) at 13:45 WIB. In the last week, Mount Semeru has erupted 35 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 300 meters above the peak or 3,976 meters above sea level.

The ash column was observed to be white to grey with thick intensity towards the southwest. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 112 seconds.

(Read: Nearly 5 Thousand Natural Disaster Events in Indonesia Throughout 2023, Forest and Land Fires Dominate)

According to the MAGMA Indonesia volcano activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 13, 2025, from 00:00-23:59 WIB showed 55 eruption tremors/earthquakes with amplitudes of 12-22 millimeters and durations of 49-217 seconds.

Furthermore, there were 5 avalanche tremors with amplitudes of 3-7 mm and durations of 64-128 seconds, and 2 exhalation tremors with an amplitude of 5 millimeters and durations of 38-40 seconds.

PVMBG urges people not to carry out any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond this distance, the public should not engage in activities within 500 meters of the river banks (river boundaries) 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 6,078 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,437 occurrences.

(Read: NTT Always Hit by Forest and Land Fires in the Last 10 Years, BMKG Urges Increased Preparedness)