Mount Semeru Erupted 4 Times, Residents Asked to Stay 5 Km from the Peak

Mount Semeru erupted with an observed eruption column height of about 400 meters above the peak on Monday (12/1/2026). ANTARA/HO-PVMBG

JAKARTA - Mount Semeru, which is on the border of Lumajang and Malang Regencies, East Java, was recorded to have erupted four times on Monday, January 12.

"The first eruption occurred at 08.09 WIB with the height of the observed eruption column of about 400 meters above the peak or 4,076 meters above sea level (msl)," said Mount Semeru Observation Post Officer, Mukdas Sofian in a written report received in Lumajang, Monday, quoted by Antara.

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

Then, in a row, it happened at 09.06 WIB, then 09.30 WIB and 10.20 WIB with an unobservable eruption visual and when the report was made by the officer, the eruption was still going on.

He said Mount Semeru was in a Level III (Alert) volcanic activity status, so the Center for Volcanology and Geological Hazard Mitigation (PVMBG) provided a number of recommendations, namely that the public should not carry out any activities in the southeast sector along Besuk Kobokan, as far as 13 km from the peak (center of the eruption).

Outside this distance, he said, the public should not carry out activities at a distance of 500 meters from the river bank (river border) along Besuk Kobokan because they have the potential to be hit by the expansion of the hot cloud and lava flow up to a distance of 17 km from the peak.

"The public is also prohibited from carrying out activities within a radius of 5 kilometers from the crater/peak of Mount Semeru, because they are prone to the danger of stone throwing (pijar)," he said.

The public needs to be aware of the potential for hot clouds, lava discharge, and lahar along the river/valley streams upstream of the Semeru Volcano peak, especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahar in small rivers which are tributaries of Besuk Kobokan.