Mount Semeru Erupts Again Tonight, Ash Plume Approximately 300 Meters High

Mount Semeru in East Java erupted again on Tuesday (7/10/2025) at 00.37 WIB. In the last week, Mount Semeru has erupted 9 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, the ash plume was observed to be approximately 300 meters above the peak (3,976 meters above sea level).

The ash plume was observed to be white to gray with moderate intensity, heading west. The eruption of Mount Semeru was still ongoing when this report was made.

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

According to MAGMA Indonesia's volcanic activity report, Mount Semeru's activity level is at Level II (Alert). Seismicity observations on October 7, 2025, at 00.00-23.59 WIB showed 83 eruption/explosion earthquakes with amplitudes of 12-23 millimeters and a duration of 50-167 seconds.

Additionally, there were 5 exhalation earthquakes with amplitudes of 3-8 millimeters and a duration of 39-105 seconds, and 1 local tectonic earthquake with an amplitude of 20 millimeters, s-p 5 seconds, and a duration of 29 seconds.

PVMBG advises against any activity in the southeast sector along Besuk Kobokan, as far as 8 kilometers from the peak (eruption center). Beyond this distance, the public should not engage in activities within 500 meters from the riverbanks 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 6,560 volcanic eruptions across Indonesia. Mount Semeru in East Java has erupted the most, with 2,570 eruptions.

(Read: Volcanic Eruption Trends in Recent Years)