Mount Semeru Erupts Again Tonight, Ash Column Height Around 700 Meters

Mount Semeru in East Java erupted again on Monday (8/25/2025) at 18:18 WIB. In the last week, Mount Semeru has erupted 5 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the height of the observed ash column was approximately 700 meters above the peak (4,376 meters above sea level).

The observed ash column was grey with thick intensity towards the west. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 141 seconds.

(Read: Volcanic Eruption Trends in Recent Years)

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismicity observations on August 25, 2025, from 00:00-23:59 WIB showed 44 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and durations of 54-183 seconds.

Furthermore, there were 5 rockfall earthquakes with amplitudes of 2-6 mm and durations of 49-90 seconds, and 14 exhalation earthquakes with amplitudes of 3-9 millimeters and durations of 35-90 seconds.

PVMBG advises against any activity 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 from the riverbanks (river borders) 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 5,795 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,314 events.

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