Warning! Mount Semeru Erupts Again Tonight (Wednesday, August 6, 2025)

Mount Semeru in East Java erupted again on Wednesday (8/6/2025) at 09:19 PM Western Indonesian Time. In the last week, Mount Semeru has erupted 13 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 reached 500 meters above the peak (4,176 meters above sea level).

The observed ash column was white to gray with thick intensity towards the north. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 109 seconds.

(Read: There Were Almost 300 Natural Disasters Until Mid-February 2024)

According to the MAGMA Indonesia volcano activity report, the activity level of Mount Semeru is at Level II (Alert). Seismic observations on August 6, 2025, from 00:00-23:59 Western Indonesian Time showed 37 eruption/explosion earthquakes with amplitudes of 10-22 millimeters and earthquake durations of 65-188 seconds.

Furthermore, there were 3 rockfall earthquakes with amplitudes of 4-10 mm and durations of 84-109 seconds, and 2 emission earthquakes with an amplitude of 6 millimeters and durations of 55-56 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 (river boundaries) along Besuk Kobokan, as there is a potential for expansion of hot clouds and lahar flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 5,489 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,198 times.

(Read: Extreme Weather to Floods, There Were 927 Natural Disaster Incidents in Indonesia Until Early May 2023)