Mount Semeru Erupts Again This Afternoon (Wednesday, September 3, 2025)

Mount Semeru in East Java erupted again on Wednesday (9/3/2025) at 4:49 PM WIB. In the last week, Mount Semeru has erupted 14 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 observed reached None meters above the peak or None meters above sea level.

The eruption''s visuals were not observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 115 seconds.

(Read: Jakarta''s Air Quality This Morning is the Second Worst in the World (Friday, June 17, 2022))

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismicity observations on September 3, 2025, from 00:00-23:59 WIB showed 52 eruption tremors with amplitudes of 10-22 millimeters and durations of 42-238 seconds.

Furthermore, there were 2 avalanche tremors with amplitudes of 4-6 mm and durations of 64-113 seconds, and 6 exhalation tremors with amplitudes of 3-8 millimeters and durations of 41-76 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, the public is advised not to conduct activities within 500 meters from the riverbanks (river border) along Besuk Kobokan due to the potential for expansion of hot clouds and lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 5,948 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,382 incidents.

(Read: How Do Residents Identify Clean Air Amid Poor Air Quality?)