Mount Semeru Erupts Again This Morning (Monday, August 4, 2025)

Mount Semeru in East Java erupted again on Monday (August 4, 2025) at 07:52 AM WIB. In the last week, Mount Semeru has erupted twice.

Reporting 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 800 meters above the peak (4,476 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 181 seconds.

(Read: Due to Forest Fires, ISPA Cases in South Kalimantan Reached 189 Thousand by September 2023)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on August 4, 2025, from 00:00-23:59 WIB showed 46 eruption tremors/earthquakes with amplitudes of 10-22 millimeters and durations of 48-169 seconds.

Furthermore, there were 5 exhalation tremors with amplitudes of 3-8 millimeters and durations of 37-75 seconds, as well as 3 harmonic tremors with amplitudes of 7-13 millimeters and durations of 95-153 seconds.

PVMBG urges 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 borders) along Besuk Kobokan due to the potential for being affected by the expansion of hot clouds and lahars up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 5,449 volcano eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,187 eruptions.

(Read: Indication of Forest and Land Fire Extent in West Kalimantan Province 2016-2025)