Mount Semeru Erupts Again Tonight (Thursday, September 18, 2025)

Mount Semeru in East Java erupted again on Thursday (September 18, 2025) at 18:40 WIB. In the last week, Mount Semeru has erupted 12 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 None meters above the peak (None meters above sea level).

No visual eruption was observed. The eruption was recorded on a seismograph with a maximum amplitude of 22 millimeters and a duration of 115 seconds.

(Read: 4.6 M Earthquake Shakes 128 Km North of Lae, Papua)

According to MAGMA Indonesia''s volcanic activity report, Mount Semeru''s activity level is at Level II (Alert). Seismic observations on September 18, 2025, at 00:00-23:59 WIB showed 56 eruption tremors/earthquakes with amplitudes of 10-22 millimeters and durations of 73-230 seconds.

Subsequently, there were 11 avalanche tremors with amplitudes of 2-8 mm and durations of 46-94 seconds, and 14 exhalation tremors with amplitudes of 3-8 millimeters and durations of 29-185 seconds.

PVMBG urges against any activity in the southeastern 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 (river border) 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 6,140 volcanic eruptions/eruptions across Indonesia. Mount Semeru in East Java has erupted the most with 2,459 eruptions.

(Read: 4.5 M Earthquake Shakes 14 Km North of San Carlos,)