Mount Semeru Erupts Again This Morning (Tuesday, August 5, 2025)

Mount Semeru in East Java erupted again on Tuesday (August 5, 2025) at 07:07 AM WIB. In the last week, Mount Semeru has erupted 4 times.

According to 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 southwest. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 110 seconds.

(Read: Indonesia Has the Most Active Volcanoes in the World)

According to MAGMA Indonesia's volcano activity report, Mount Semeru's activity level is at Level II (Alert). Seismic observations on August 5, 2025, from 00:00-23:59 WIB showed 40 eruption tremors/earthquakes with amplitudes of 10-22 millimeters and durations of 52-211 seconds.

Additionally, there were 2 rockfall tremors with amplitudes of 4-8 mm and durations of 84-147 seconds, and 8 emission tremors with amplitudes of 3-8 millimeters and durations of 42-59 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, up to 8 kilometers from the peak (eruption center). Beyond this distance, the public should not engage in activities within 500 meters of the river banks (riverine 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 5,459 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,189 times.

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