Mount Semeru Erupts Again This Morning (Monday, January 12, 2026)

Mount Semeru in East Java erupted again on Monday (January 12, 2026) at 08:09 AM Western Indonesian Time. In the last week, Mount Semeru only erupted once.

Citing 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 400 meters above the peak (4,076 meters above sea level).

The ash column was observed to be white to gray with thick intensity towards the northeast. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 110 seconds.

(Read: There were 137 Natural Disaster Events Nearing the End of January 2024, Floods Were the Most Frequent)

According to the MAGMA Indonesia volcano activity report, the activity level of Mount Semeru is at Level III (Alert). Seismic observations on January 12, 2026, from 00:00-06:00 AM WIB, showed 38 eruption tremors with an amplitude of 15-22 millimeters and a duration of 86-225 seconds.

Subsequently, there were 3 avalanche tremors with an amplitude of 4-6 mm and a duration of 40-58 seconds, and 1 exhalation tremor with an amplitude of 6 millimeters and a duration of 63 seconds.

PVMBG urged people not to engage in any activities in the southeastern sector along Besuk Kobokan, as far as 13 kilometers from the peak (eruption center). Beyond that distance, the public is advised not to engage in activities within 500 meters from the riverbanks (river border) along Besuk Kobokan, as there is a potential for expansion of hot clouds and lahars up to 17 kilometers from the peak.

Throughout 2026, MAGMA Indonesia has recorded 168 volcanic eruptions across Indonesia. Mount Semeru in East Java had the most eruptions, with 90 occurrences.

(Read: Floods Dominated Natural Disasters in Indonesia in Early 2024)