Mount Semeru Erupts Again This Morning (Friday, December 26, 2025)

Mount Semeru in East Java erupted again on Friday (12/26/2025) at 07:31 AM WIB. In the last week, Mount Semeru has erupted 34 times.

Based on eruption information from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application, 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 northeast and east. The eruption was recorded on a seismograph with a maximum amplitude of 17 millimeters and a duration of 98 seconds.

(Read: There are Still 381 High-Risk Forest and Land Fire Hotspots in Indonesia in Early 2023)

According to the MAGMA Indonesia volcano activity report, Mount Semeru's activity level is at Level III (Alert). Seismicity observations on December 26, 2025, from 00:00-06:00 AM WIB, showed 42 eruption tremors/earthquakes with amplitudes of 10-23 millimeters and durations of 88-203 seconds.

Additionally, there were 3 avalanche tremors with an amplitude of 2 mm and durations of 39-45 seconds, and 2 distant tectonic earthquakes with amplitudes of 5-8 millimeters, S-P times of 18-26 seconds, and durations of 55-74 seconds.

PVMBG advises against any activities in the southeast sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond this distance, the public is advised not to engage in activities within 500 meters from the riverbanks along Besuk Kobokan, as there is a potential for hot ash clouds and lava flows to extend up to 17 kilometers from the peak.

Throughout 2025, MAGMA Indonesia has recorded 7,513 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 3,132 occurrences.

(Read: BNPB Recorded 52 Natural Disasters in Mid-August 2023, Mostly Forest and Land Fires)