Warning! Mount Semeru Erupts Again This Morning (Monday, September 1, 2025)

Mount Semeru in East Java erupted again on Monday (1/9/2025) at 07.59 WIB. In the last week, Mount Semeru has erupted 2 times.

Reporting 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 500 meters above the peak (4,176 meters above sea level).

The ash column was observed to be gray with thick intensity towards the southwest and west. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 124 seconds.

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

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 1, 2025, at 00.00-23.59 WIB showed 58 eruption earthquakes with amplitudes of 10-22 millimeters and durations of 45-188 seconds.

Then, 2 avalanche earthquakes with amplitudes of 2-4 mm and durations of 46-61 seconds, and 8 emission earthquakes with amplitudes of 3-8 millimeters and durations of 34-85 seconds occurred.

PVMBG urges not to carry out any activities in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond that distance, people should not conduct activities within 500 meters from the river bank (river border) 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 5,918 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions with 2,370 occurrences.

(Read: Air Quality in Indonesia Slightly Improved in 2021)