Inp.polri.go.id - Lumajang. Mount Semeru, located on the border of Lumajang and Malang in East Java, erupted Saturday morning (11/1/2025), sending an ash column 600 meters above its summit.

"An eruption occurred at 7.23 am, with the ash column reaching 600 meters above the summit, or 4,276 meters above sea level," Yadi Yuliandi, an observer at the Semeru Monitoring Post, told antaranews.com. 

The ash plume, gray and thick, drifted northeast, with seismic activity recorded at a maximum amplitude of 22 mm lasting 100 seconds.

Semeru, currently at Alert Level II (Caution), has been erupting intermittently. Earlier eruptions occurred at 4.08 am, 4.31 am (with a 700-meter ash column), and 5.45 am (unobservable visually).

Authorities advise against activities within 8 kilometers of the Besuk Kobokan sector and prohibit access within 500 meters of riverbanks in the area. 

Residents are told to remain vigilant for pyroclastic flows, lava, and rain-triggered lahars in the Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat river basins.

(mg/inp/pr/nm)