Mount Semeru Erupts Again This Afternoon, Volcanic Ash Plume Approximately 500 Meters High

Mount Semeru in East Java erupted again on Monday (9/22/2025) at 4:18 PM WIB. In the last week, Mount Semeru has erupted 8 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 ash column was observed to be white to grey with thick intensity towards the southwest and west. The eruption was recorded on a seismograph with a maximum amplitude of 21 millimeters and a duration of 124 seconds.

(Read: A 4.7 M Earthquake Rocks the Bonin Islands Region)

According to MAGMA Indonesia''s volcano activity report, Mount Semeru''s activity level is at Level II (Alert). Seismicity observations on September 22, 2025, from 00:00-23:59 WIB showed 70 eruption earthquakes with amplitudes of 10-22 millimeters and durations of 50-195 seconds.

Additionally, there were 3 avalanche earthquakes with amplitudes of 4-6 mm and durations of 57-59 seconds, and 14 exhalation earthquakes with amplitudes of 3-8 millimeters and durations of 34-77 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 is advised not to 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 lava flows up to 13 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 6,272 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 2,474 occurrences.

(Read: A 4.5 M Earthquake Rocks 94 Km Southwest of Banda Aceh,)